Our Common Insects
by A. S. Packard · English · Gutenberg #24409 · 442,701 chars · public domain (US)
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Title: Our Common Insects
Author: A. S. Packard
Release date: January 23, 2008 [eBook #24409]
Language: English
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Produced by Bryan Ness, Janet Blenkinship and the Online
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book was produced from scanned images of public domain
material from the Google Print project.)
OUR COMMON INSECTS.
[Illustration: AMERICAN SILK WORM (MALE).]
OUR
COMMON INSECTS.
A POPULAR ACCOUNT OF THE INSECTS
OF OUR
Fields, Forests, Gardens and Houses.
Illustrated with 4 Plates and 268 Woodcuts.
BY
A. S. PACKARD, JR.,
Author of "A GUIDE TO THE STUDY OF INSECTS."
SALEM.
NATURALISTS' AGENCY.
BOSTON: Estes & Lauriat. NEW YORK: Dodd & Mead.
1873.
Entered, according to Act of Congress, in the year 1878, by
F. W. PUTNAM & CO.,
in the Office of the Librarian of Congress at Washington.
PRINTED AT
THE SALEM PRESS,
F. W. PUTNAM & CO.,
Proprietors.
DEDICATION.
TO SAMUEL H. SCUDDER.
MY DEAR SCUDDER:--You and I were drawn together many years ago by a
common love for insects and their ways.
I dedicate this little volume of ephemeral essays to you in recognition
of your worth as a man and a scientist, and as a token of warm
friendship.
Yours sincerely,
A. S. PACKARD, JR.
PREFACE.
This little volume mainly consists of a reprint of a series of essays
which appeared in the "American Naturalist" (Vols. i-v, 1867-71). It is
hoped that their perusal may lead to a better acquaintance with the
habits and forms of our more common insects. The introduction was
written expressly for this book, as well as Chapter XIII, "Hints on the
Ancestry of Insects." The scientific reader may be drawn with greater
interest to this chapter than to any other portion of the book. In this
discussion of a perhaps abstruse and difficult theme, his indulgence is
sought for whatever imperfections or deficiencies may appear. Our
systems of classification may at least be tested by the application of
the theory of evolution. The natural system, if we mistake not, is the
genealogy of organized forms; when we can trace the latter, we establish
the former. Considering how much naturalists differ in their views as to
what is a natural classification, it is not strange that a genealogy of
animals or plants seems absurd to many. To another generation of
naturalists it must, perhaps, be left to decide whether to attempt the
one is more unphilosophical than to attempt the other.
Most of the cuts have already appeared in the "Guide to the Study of
Insects" and the "American Naturalist," where their original sources are
given, while a few have been kindly contributed by Prof. A. E. Verrill,
the Boston Society of Natural History, and Prof. C. V. Riley, and three
are original.
SALEM, June, 1873.
OUR COMMON INSECTS.
INTRODUCTORY.
_What is an Insect?_ When we remember that the insects alone comprise
four-fifths of the animal kingdom, and that there are upwards of 200,000
living species, it would seem a hopeless task to define what an insect
is. But a common plan pervades the structure of them all. The bodies of
all insects consist of a succession of rings, or segments, more or less
hardened by the deposition of a chemical substance called chitine; these
rings are arranged in three groups: the head, the thorax, or middle
body, and the abdomen or hind body. In the six-footed insects, such as
the bee, moth, beetle or dragon fly, four of these rings unite early in
embryonic life to form the head; the thorax consists of three, as may be
readily seen on slight examination, and the abdomen is composed either
of ten or eleven rings. The body, then, seems divided or _insected_ into
three regions, whence the name _insect_.
The head is furnished with a pair of antennæ, a pair of jaws
(mandibles), and two pairs of maxillæ, the second and basal pair being
united at their base to form the so-called labium, or under lip. These
four pairs of appendages represent the four rings of the head, to which
they are appended in the order stated above.
A pair of legs is appended to each of the three rings of the thorax;
while the first and second rings each usually carry a pair of wings.
The abdomen contains the ovipositor; sometimes, as in the bees and
wasps, forming a sting. In the spiders (Fig. 1), however, there are no
antennæ, and the second maxillæ, or labium, is wanting. Moreover, there
are four pairs of legs. The centipedes (Fig. 2, a Myriopod) also differ
from the rest of the insects in having an indefinite number of abdominal
rings, each bearing a pair of legs.
[Illustration: 1. Spider (Tegenaria).]
On examining the arrangement of the parts within, we find the nervous
cord, consisting of two chains of swellings, or nerve-knots, resting
upon the floor or under side of the body; and the heart, or dorsal
vessel, situated just under the skin of the back; and in looking at
living caterpillars, such as the cut-worm, and many thin-skinned aquatic
larvæ, we can see this long tubular heart pulsating about as often as
our own heart, and when the insect is held against its will, or is
agitated, the rapidity of the pulsations increases just as with us.
[Illustration: 2. Centipede.]
Insects do not breathe as in the higher animals by taking the air into
the mouth and filling the lungs, but there are a series of holes or
pores along the side of the body, as seen in the grub of the humble bee,
through which the air enters and is conveyed to every part of the body
by an immense number of air tubes. (Fig. 3, air tubes, or tracheæ, in
the caudal appendage of the larva of a dragon fly). These air tubes are
everywhere bathed by the blood, by which the latter becomes oxygenated.
[Illustration: 3. Caudal appendage of larva of Agrion.]
Indeed the structure of an insect is entirely different from that of man
or the quadrupeds, or any other vertebrate animal, and what we call
head, thorax, abdomen, gills, stomach, skin, or lungs, or jaws, are
called so simply for convenience, and not that they are made in the same
way as those parts in the higher animals.
An insect differs from a horse, for example, as much as a modern
printing press differs from the press Franklin used. Both machines are
made of iron, steel, wood, etc., and both print; but the plan of their
structure differs throughout, and some parts are wanting in the simpler
press which are present and absolutely essential in the other. So with
the two sorts of animals; they are built up originally out of
protoplasm, or the original jelly-like germinal matter, which fills the
cells composing their tissues, and nearly the same chemical elements
occur in both, but the mode in which these are combined, the arrangement
of their products: the muscular, nervous and skin tissues, differ in the
two animals. The plan of structure, namely, the form and arrangement of
the body walls, the situation of the appendages to the body, and of the
anatomical systems within, i.e., the nervous, digestive, circulatory,
and respiratory systems, differ in their position in relation to the
walls of the body. Thus while the two sorts of animals reproduce their
kind, eat, drink and sleep, see, hear and smell, they perform these acts
by different kinds of organs, situated sometimes on the most opposite
parts of the body, so that there is no comparison save in the results
which they accomplish; they only agree in being animals, and in having a
common animal nature.
[Illustration: 4. Different forms of jaws.]
[Illustration: 5. Mouth parts of the Larva of a Beetle.]
[Illustration: 6. Maxilla of a Beetle.]
_How Insects Eat._ The jaws of insects (Fig. 4) are horny processes
situated on each side of the mouth. They are variously toothed, so as to
tear the food, and move horizontally instead of up and down as in the
horse. The act of taking the food, especially if the insect be
carnivorous in its habits, is quite complex, as not only the true jaws,
but the accessory jaws (maxillæ, Fig. 5, _a_, upper, b, under side of
the head of a young beetle; _at_, antennæ, _md_, mandible, _mx_,
maxillæ, _mx_[1], labium) and the feelers (palpi) attached to the
maxillæ, and the under lip (labium) are of great service in enabling the
insect to detect its food both by the senses of touch and smell. The
maxillæ are in the fully grown beetle (Fig. 6) divided into three lobes,
the outermost forming the palpus, and the two others forming sharp
teeth, often provided with hairs and minute brushes for cleansing the
adjoining parts; these strong curved teeth are used in seizing the food
and placing it between the grinders, where it is crushed, prepared for
digestion and swallowed. Fig. 7 represents the mouth parts of the humble
bee. (_b_, upper lip; _d_, mandible; _e_, maxilla; _f_, maxillary
palpus; _g_, tongue; _ih_, labium and tabial palpi; _k_, eye.)
[Illustration: 7. Mouth parts of a Humble Bee.]
The alimentary canal passes through the middle of the body, the stomach
forming usually a simple enlargement. Just before the stomach in certain
insects, as the grasshopper, is a gizzard armed with rows of powerful
horny teeth for finely crushing grass.
Insects eat almost incredible quantities of food when young and growing
rapidly. Mr. Trouvelot tells us in the "American Naturalist" that the
food taken by a single American Silk-worm in fifty-six days is equal to
eighty-six thousand times its primitive weight! On the other hand, after
the insect has finished its transformations, it either takes no food at
all, as in the May fly, or merely sips the honey of flowers, as in the
butterfly, while the June beetle and many others like it eat the leaves
of trees, and the tiger and ground beetles feed voraciously on other
insects.
_How Insects Walk._ In man and his allies, the vertebrates, the process
of walking is a most difficult and apparently dangerous feat. To
describe the mechanics of walking, the wonderful adaptation of the
muscles and bones for the performance of this most ordinary action of
life, would require a volume. The process is scarcely less complex in
insects. Lyonnet found 3,993 muscles in a caterpillar, and while a large
proportion belong to the internal organs, over a thousand assist in
locomotion. Hence the muscular power of insects is enormous. A flea will
leap two hundred times its own height, and certain large, solid beetles
will move enormous weights as compared to the bulk of their bodies.
[Illustration: 8. Larva of a beetle (Photuris).]
In walking, as seen in the accompanying figure (Fig. 8), three legs are
thrown forward at a time, two on one side and one on the other.
Flies and many other insects can walk upside down, or on glass, as
easily as on a level surface. A fly's foot, as in most other insects,
consists of five joints (tarsal joints), to the last one of which is
appended a pair of stout claws, beneath which is a flat, soft, fleshy
cushion or pad, split into two (sometimes three) flaps, beset on the
under surface with fine hairs. A part of these hairs are swollen at the
end, which is covered with "an elastic membranous expansion, capable of
close contact with a highly polished surface, from which a minute
quantity of a clear, transparent fluid is emitted when the fly is
actively moving." (T. West.) These hairs are hence called holding, or
tenent, hairs. With the aid of these, but mainly, as Mr. West insists,
by the pressure of the atmosphere, a fly is enabled to adhere to
perfectly smooth surfaces. His studies show the following curious facts.
"That atmospheric pressure, if the area of the flaps be alone
considered, is equal to just one-half the weight of a fly. If the area
covered by the tenent hairs be added, an increase of pressure is gained,
equal to about one-fourth the weight of a fly. This leaves one-fourth to
be accounted for by slight viscidity of the fluid, by the action I have
so often alluded to, which may be called 'grasping,' by molecular
attraction, and, doubtless, by other agents still more subtle, with
which we have at present scarcely any acquaintance."
_How Insects Fly._ Who of us, as remarked by an eminent ornithologist,
can even now explain the long sustained, peculiar flight of the hawk, or
turkey buzzard, as it sails in the air without changing the position of
its wings? and, we would add, the somewhat similar flight of a
butterfly? It is the poetry of motion, and a marvellous exhibition of
grace and ease, combined with a wonderful underlying strength and
lightness of the parts concerned in flight.
Before we give a partial account of the results obtained by the delicate
experiments of Professor Marey on the flight of birds and insects, our
readers should be reminded of the great differences between an insect
and a bird, remembering that the former, is, in brief, a chitinous sac,
so to speak, or rather a series of three such spherical or elliptical
sacs (the head, thorax and abdomen); the outer walls of the body forming
a solid but light crust, to which are attached broad, membranous wings,
the wing being a sort of membranous bag stretched over a framework of
hollow tubes (the tracheæ), so disposed as to give the greatest
lightness and strength to the wing. The wings are moved by powerful
muscles of flight, filling up the cavity of the thorax, just as the
muscles are the largest about the thorax of a bird. Moreover in the
bodies of insects that fly (such as the bee, cockchafer, and dragon
fly), as distinguished from those that creep exclusively, the air tubes
(tracheæ) which ramify into every part of the body, are dilated here and
there, especially in the base of the abdomen, into large sacs, which are
filled with air when the insect is about to take flight, so that the
specific gravity of the body is greatly diminished. Indeed, these air
sacs, dilatable at will by the insect, may be compared to the swimming
bladder of fishes, which enables them to rise and fall at will to
different levels in the sea, thus effecting an immense saving of the
labor of swimming. In the birds, as every body knows who has eaten a
chicken, or attended the dissection of a Thanksgiving turkey, the soft
parts are external, attached to the bony framework comprising the
skeleton, the wing bones being directly connected with the central back
bone; so that while these two sorts of animated flying machines are so
different in structure, they yet act in much the same manner when on the
wing. The difference between them is clearly stated by Marey, some of
whose conclusions we now give almost word for word.
The flight of butterflies and moths differs from that of birds in the
almost vertical direction of the stroke of their wings, and in their
faculty of sailing in the air without making any movements; though
sometimes in the course they pursue they seem to resemble birds in their
flight.
The flight of insects and birds moreover differs in the form of the
trajectory in space; in the inclination of the plane in which the wings
beat; in the role of each of the two alternating (and in an inverse
sense) movements that the wings execute; as also in the facility with
which the air is decomposed during these different movements. As the
wings of a fly are adorned with a brilliant array of colors, we can
follow the trajectory or figure that each wing writes in the air. It is
of the form of a figure of eight (Fig. 9), first discovered by Professor
J. Bell Pettigrew of Edinburgh.
[Illustration: 9. Figure cut by an insect's wing.]
[Illustration: 10. Figure cut by a bird's wing.]
By an ingenious machine, specially devised for the purpose, Professor
Marey found that a bird's wing moves in an ellipse, with a pointed
summit (Fig. 10). The insect beats the air in a distinctly horizontal
plane, but the bird in a vertical plane. The wing of an insect is
impervious to the air; while the bird's wing resists the air only on
its under side. Hence, there are two sorts of effects; in the insect
the up and down strokes are active; in the bird, the lowering of the
wing is the only active period, though the return stroke seems to
sustain the bird, the air acting on the wing. The bird's body is
horizontal when the wing gives a downward stroke; but when the beat is
upward, the bird is placed in an inclined plane like a winged
projectile, and mounts up on the air by means of the inclined surfaces
that it passively offers to the resistance of this fluid.
[Illustration: 11. Trajectory of an insect's wing.]
[Illustration: 12. Trajectory of a bird's wing.]
In an insect, an energetic movement is equally necessary to strike the
air at both beats up and down. In the bird, on the contrary, one active
beat only is necessary, the down beat. It creates at that time all the
motive force that will be dispensed during the entire revolution of the
wing. This difference is due to the difference in form of the wing. The
difference between the two forms of flight is shown by an inspection of
the two accompanying figures (11, 12). An insect's wing is small at the
base and broad at the end. This breadth would be useless near the body,
because at this point the wing does not move swiftly enough to strike
the air effectively. The type of the insectean wing is designed, then,
simply to strike the air. But in the bird the wing plays also a passive
role, _i. e._, it receives the pressure of the air on its under side
when the bird is projected rapidly onward by its acquired swiftness. In
these conditions the whole animal is carried onward in space; all the
points of its wing have the same velocity. The neighboring regions of
the body are useful to press upon the air, which acts as on a paper
kite. The base of the wing also, in the bird, is broad, and provided
with feathers, which form a broad surface, on which the air presses with
a force and method very efficacious in supporting the bird. Fig. 12
gives an idea of this disposition of the wing at the active and passive
time in a bird.
The inner half of the wing is the passive part of the organ, while the
external half, that which strikes the air, is the active part. A fly's
wing makes 330 revolutions in a second, executing consequently 660
simple oscillations; it ought at each time to impress a lateral
deviation of the body of the insect, and destroy the velocity that the
preceding oscillation has given it in a contrary direction. So that by
this hypothesis the insect in its flight only utilizes fifty to one
hundred parts (or one-half) of the resistance that the air furnishes it.
[Illustration: 13. A bird on the wing.]
In the bird (Fig. 13), at the time of lowering the wings, the oblique
plane which strikes the air, in decomposing the resistance, produces a
vertical component which resists the weight of the body, and a
horizontal component which imparts swiftness. The horizontal component
is not lost, but is utilized during the rise of the wing, as in a paper
kite when held in the air against the wind. Thus the bird utilizes
seventy-five out of one hundred parts of the resistance that the air
furnishes. The style of flight of birds is, therefore, theoretically
superior to that of insects. As to the division of the muscular force
between the resistance of the air and the mass of the body of the bird,
we should compare the exertion made in walking on sand, for example, as
compared with walking on marble. This is easy to measure. When a fish
strikes the water with its tail to propel itself forward, it performs a
double task; one part consists in pushing backwards a certain mass of
water with a certain swiftness, and the other in pushing on the body in
spite of the resistance of the surrounding fluid. This last portion of
the task only is utilized. It would be greater if the tail of the fish
encountered a solid object. Almost all the propelling agencies employed
in navigation undergo this loss of labor, which depends on the mobility
of the _point d' appui_. The bird is placed among conditions especially
unfavorable.
_The Senses of Insects._ The eyes of insects are sometimes so large as
to envelop the head like an Elizabethan ruffle, and the creature's head,
as in the common house fly, seems all eyes. And this is almost literally
the case, as the two great staring eyes that almost meet on the top of
the head to form one, are made up of myriads of simple eyes. Each facet
or simple eye is provided with a nerve filament which branches off from
the main optic nerve, so that but one impression of the object perceived
is conveyed to the brain; though it is taught by some that objects
appear not only double but a thousand times multiplied. But we should
remember that with our two eyes we see double only when the brain is
diseased. Besides the large ordinary compound eyes, many insects possess
small, simple eyes, like those of the spider. The great German
anatomist, Johannes Müller, believed that the compound eyes were adapted
for the perception of distant objects, while those nearer are seen by
the simple eyes. But it may be objected to this view that the spiders,
which have only simple eyes, apparently see both near and remote objects
as well as insects.
The sense of touch is diffused all over the body. As in the hairs of the
head and face of man, those of insects are delicate tactile organs; and
on the antennæ and legs (insects depending on this sense rather than
that of sight) these appendages are covered with exquisitely fine
hairs. It is thought by some that the senses of hearing and smell are
lodged in the antennæ, these organs thus combining the sense of feeling
with those of hearing and smelling. And the researches of anatomists
lend much probability to the assertion, since little pits just under the
skin are found, and even sometimes provided with grains of sand in the
so-called ear of the lobster, etc., corresponding to the ear bones of
the higher animals, the pits being connected with nerves leading to the
brain. We have detected similar pits in the under side of the palpi of
the Perla. It seems not improbable that these are organs of smell, and
placed in that part of the appendage nearest the mouth, so as to enable
the insect to select its proper food by its odor. Similar organs exist
on the caudal appendages of a kind of fly (Chrysopila), while the long,
many-jointed caudal filaments of the cockroach are each provided with
nearly a hundred of these little pits, which seem to be so many noses.
Thus Lespès, a Swiss anatomist, in his remarks on the auditory sacs,
which he says are found in the antennæ of nearly all insects, declares
that as we have in insects compound eyes, so we have compound ears. We
might add that in the abdominal appendage of the cockroach we have a
compound nose, while in the feelers of the Perla, and the caudal
appendage of the Chrysopila, the "nose" is simple. We might also refer
here to Siebold's discovery of ears at the base of the abdomen of some,
and in the forelegs of other kinds, of grasshoppers. Thus we need not be
surprised at finding ears and noses scattered, as it were, sometimes
almost wantonly over the bodies of insects (in many worms the eyes are
found all over the body), while in man and his allies, from the monkey
down to the fish, the ears and nose invariably retain the same relative
place in the head.
_How Insects Grow._ When beginning our entomological studies no fact
seemed more astonishing to our boyish mind than the thought that the
little flies and midges were not the sons and daughters of the big
ones. If every farmer and gardener knew this single fact it would be
worth their while. The words _larva_ and _pupa_ will frequently occur in
subsequent pages, and they should be explained. The caterpillar (Fig.
14, _a_) represents the earliest stage or babyhood of the butterfly, and
it is called _larva_, from the Latin, meaning a mask, because it was
thought by the ancients to mask the form of the adult butterfly.
[Illustration: 14. _a_ Larva, _b_ chrysalis of a butterfly.]
When the caterpillar has ended its riotous life, for its appetite almost
transforms its being into the very incarnation of gluttony, it suddenly,
as if repenting of its former life as a _bon vivant_, seeks a solitary
cell or hole where like a hermit it sits and leads apparently about as
useless an existence. But meanwhile strange processes are going on
beneath the skin; and after a few convulsive struggles the back splits
open, and out wriggles the chrysalis, a gorgeous, mummy-like form, its
body adorned with golden and silvery spots. Hence the word chrysalis
(Fig. 14, _b_), from the Greek, meaning golden, while the Latin word
_pupa_, meaning a baby or doll, is indicative of its youth. In this
state it hangs suspended to a twig or other object; while the silk worm,
and others of its kind, previous to moulting, or casting their skins,
spin a silken cocoon, which envelops and protects the chrysalis.
[Illustration: 15. Imago or adult Butterfly.]
At the given time, and after the body of the adult has fully formed
beneath the chrysalis skin, there is another moult, and the butterfly,
with baggy, wet wings, creeps out. The body dries, the skin hardens, the
wings expand, and in a few moments, sometimes an hour, the butterfly
(Fig. 15) proudly sails aloft, the glory and pride of the insect world.
We shall see in the ensuing chapters how varied are the larvæ and pupæ
of insects, and under what different guises insects live in their early
stages.
[Illustration: Larva, pupa, and adult of a Leaf Beetle (Galeruca).]
OUR COMMON INSECTS.
CHAPTER I.
THE HOME OF THE BEES.
The history of the Honey bee, its wonderful instincts, its elaborate
cells and complex economy, have engrossed the attention of the best
observers, even from the time of Virgil, who sang of the Ligurian bee.
The literature of the art of bee-keeping is already very extensive.
Numerous bee journals and manuals of bee-keeping testify to the
importance of this art, while able mathematicians have studied the mode
of formation of the hexagonal cells,[1] and physiologists have
investigated the intricate problems of the mode of generation and
development of the bee itself.
In discussing these difficult questions, we must rise from the study of
the simple to the complex, remembering that--
"All nature widens upward. Evermore
The simpler essence lower lies:
More complex is more perfect--owning more
Discourse, more widely wise."
and not forget to study the humbler allies of the Honey bee. We shall,
in observing the habits and homes of the wild bees, gain a clearer
insight into the mysteries of the hive.
The great family of bees is divided into social and solitary species.
The social kinds live in nests composed of numerous cells in which the
young brood are reared. These cells vary in form from those which are
quite regularly hexagonal, like those of the Hive bee, to those which
are less regularly six-sided, as in the stingless bee of the tropics
(Melipona), until in the Humble bee the cells are isolated and
cylindrical in form.
Before speaking of the wild bees, let us briefly review the life of the
Honey bee. The queen bee having wintered over with many workers, lays
her eggs in the spring, first in the worker, and, at a later period, in
the drone-cells. Early in the summer the workers construct the large,
flask-shaped queen-cells, which are placed on the edge of the comb, and
in these the queen larvæ are fed with rich and choice food. The old
queen deserts the nest, forming a new colony. The new-born queen takes
her marriage flight high in the air with a drone, and on her return
undertakes the management of the hive, and the duty of laying eggs. When
the supply of queens is exhausted, the workers destroy the drones. The
first brood of workers live about six weeks in summer, and then give way
to a new brood. The queens, according to Von Berlepsch, are known to
live five years, and during their whole life lay more than a million
eggs.
In the tropics, the Honey bee is replaced by the Meliponas and Trigonas.
They are minute, stingless bees, which store up honey and live in
colonies often of immense extent. The cells of Melipona are hexagonal,
nearly approaching in regularity those of the Hive bee, while the honey
cells are irregular, being much larger cavities, which hold about
one-half as much honey as a cell of the Humble bee. "Gardner, in his
travels, states that many species of Melipona build in the hollow trunks
of trees, others in banks; some suspend their nests from the branches of
trees, whilst one species constructs its nest of clay, it being of large
size." (F. Smith.)
In a nest of the coal-black Trigona (Trigona carbonaria), from eastern
Australia, Mr. F. Smith, of the British Museum, found from four hundred
to five hundred dead workers, but no females. The combs were arranged
precisely similar to those of the common wasp. The number of honey-pots
which were placed at the foot of the nest was two hundred and fifty. Mr.
Smith inclines to the opinion that the hive of Trigona contains several
prolific females, as the great number of workers can only be thus
explained, and M. Guérin found six females in a nest of the Tawny-footed
Melipona (M. fulvipes).
At home, our nearest ally of the true Honey bee, is the Humble bee
(Bombus), of which over forty species are known to inhabit North
America.
The economy of the Humble bee is thus: the queen awakens in early spring
from her winter's sleep under leaves or moss, or in the last year's
nest, and selects a nesting place, generally in an abandoned nest of a
field-mouse, or beneath a stump or sod, and "immediately," according to
Mr. F. W. Putnam,[2] "collects" a small amount of pollen mixed with
honey, and in this deposits from seven to fourteen eggs, gradually
adding to the pollen mass until the first brood is hatched. She does not
wait, however, for one brood to be hatched before laying the eggs of
another, but, as soon as food enough has been collected, she lays the
eggs for a second. The eggs are laid, in contact with each other, in one
cavity of the mass of pollen, with a part of which they are slightly
covered. They are very soon developed; in fact, the lines are nowhere
distinctly drawn between the egg and the larva, the larva and pupa, and
again between the latter and the imago; a perfect series, showing this
gradual transformation of the young to the imago can be found in almost
every nest.
[Illustration: 15. Cell and Eggs of Bombus.]
"As soon as the larvæ are capable of motion and commence feeding, they
eat the pollen by which they are surrounded, and, gradually separating,
push their way in various directions. Eating as they move, and
increasing in size quite rapidly, they soon make large cavities in the
pollen mass. When they have attained their full size, they spin a silken
wall about them, which is strengthened by the old bees covering it with
a thin layer of wax, which soon becomes hard and tough, thus forming a
cell (Fig. 15, 1, cell containing a larva, on top of which (2) is a
pollen mass containing three eggs). The larvæ now gradually attain the
pupa stage, and remain inactive until their full development. They then
cut their way out, and are ready to assume their duties as workers,
small females, males or queens.
"It is apparent that the irregular disposition of the cells is due to
their being constructed so peculiarly by the larvæ. After the first
brood, composed of workers, has come forth, the queen bee devotes her
time principally to her duties at home, the workers supplying the colony
with honey and pollen. As the queen continues prolific, more workers are
added, and the nest is rapidly enlarged.
"About the middle of summer, eggs are deposited, which produce both
small females and males." ... "All eggs laid after the last of July
produce the large females, or queens, and, the males being still in the
nest, it is presumed that the queens are impregnated at this time, as on
the approach of cold weather all except the queens, of which there are
several in each nest, die."
While the Humble bee in some respects shows much less instinct than the
solitary bees mentioned below, it stands higher in the series, however,
from having workers, as well as males and females, who provide food for
the young. The labors of the Mason bees, and their allies, terminate
after the cell is once constructed and filled with pollen. The eggs are
then left to hatch, and the young care for themselves, though the adult
bee shows greater skill in architecture than the Humble bee. It is thus
throughout nature. Many forms, comparatively low in the scale of life,
astonish us with certain characters or traits, reminding us of beings
much superior, physically and intellectually. The lower forms constantly
reach up and in some way ally themselves with creatures far more highly
organized. Thus the fish-like seal reminds us strikingly of the dog,
both in the form of the head, in its docility and great intelligence
when tamed, and even in its bark and the movements of the head.
[Illustration: 16. Meloë.]
The parasites of the Humble bee are numerous. Such are the species of
Apathus, which so closely resembles the Humble bee itself, that it
requires long study to distinguish it readily. Its habits are not known,
other than that it is found in the nests of its host. It differs from
the Humble bee in having no pollen-basket, showing that its larvæ must
feed on the food stored up by their host, as it does not itself collect
it. The mandibles also are not, like those of Bombus, trowel-shaped for
architectural purposes, but acutely triangular, and are probably not
used in building.
The caterpillars of various moths consume the honey and waxen cells; the
two-winged flies, Volucella and Conops, and the larvæ of what is either
an Anthomyia or Tachina-like fly, and several species of another genus
of flies, Anthrax, together with several beetles, such as the Meloë
(Fig. 16), Stylops (Fig. 17, male; 18_b_, female; _a_, position in the
body of its host), and Antherophagus prey upon them.
[Illustration: 17. Male Stylops.]
The power of boring the most symmetrical tunnels in solid wood reaches
its perfection in the large Virginian Carpenter bee (Xylocopa Virginica,
Fig. 19). This bee is as large as, and some allied exotic species are
often considerably larger than, the Humble bee, but not clothed with
such dense hairs. We have received from Mr. James Angus, of West Farms,
N. Y., a piece of trellis from a grape vine, made of pine wood,
containing the cells and young in various stages of growth, together
with the larvæ and chrysalids of Anthrax sinuosa (Fig. 20), a species of
fly parasitic on the larva. The maggot buries its head in the soft body
of the young bee and feeds on its juices.
Mr. Angus thus writes us regarding its habits, under date of July 19: "I
asked an intelligent and observing carpenter yesterday, if he knew how
long it took the Xylocopa to bore her tunnel. He said he thought she
bored about one-quarter of an inch a day. I don't think myself she
bores more than one-half inch, if she does that. If I mistake not, it
takes her about two days to make her own length at the first start; but
this being across the grain of the wood, may not be so easily done as
the remainder, which runs parallel with it. She always follows the grain
of the wood, with the exception of the entrance, which is about her own
length. The tunnels run from one to one and a half feet in length. They
generally run in opposite directions from the opening, and sometimes
other galleries are run, one directly above the other, using the same
opening. I think they only make new tunnels when old ones are not to be
found, and that the same tunnels are used for many years. Some of the
old tunnels are very wide. I have found parts of them about an inch in
diameter. I think this is caused by rasping off the sides to procure the
necessary material for constructing their cells. The partitions are
composed of wood raspings, and some sticky fluid, probably saliva, to
make them adhere.
[Illustration: 18. Female Stylops.]
[Illustration: 19. Carpenter Bee.]
"The tunnels are sometimes taken possession of by other bees and wasps.
I think when this is the case, the Xylocopa prefers making a new cell,
to cleaning out the dirt and rubbish of the other species. I frequently
find these bees remaining for a long time on the wing close to the
opening, and bobbing their heads against the side, as if fanning air
into the opening. I have seen them thus employed for twenty minutes.
Whether one bee or more makes the tunnel, that is, whether they take
turns in boring, I cannot at present say. In opening the cells (Fig.
21), more than one are generally found, even at this season. About two
weeks ago; I found as many as seven, I think, in one."[3]
The hole is divided by partitions into cells about seven-tenths of an
inch long. These partitions are constructed of the coarse dust or
chippings made by the bee in eating out her cells, for our active little
carpenter is provided with strong cutting jaws, moved by powerful
muscles, and on her legs are stiff brushes of hair for cleaning out the
tunnel as she descends into the heart of the solid wood. She must throw
out the chips she bites off with her powerful mandibles from the sides
of the burrow, by means of her hind legs, passing the load of chips
backwards out of the cell with her fore limbs, which she uses as hands.
[Illustration: 20. Larva and Pupa of Anthrax.]
The partitions are built most elaborately of a single flattened band of
chips, which is rolled up into a coil four layers deep. One side,
forming the bottom of the cell, is concave, being beaten down and
smoothed off by the bee. The other side of the partition, forming the
top of the cell, is flat and rough.
[Illustration: 21. Nest of Carpenter Bee.]
At the time of opening the burrow, July 8th, the cells contained nearly
full-grown larvæ, with some half developed. They were feeding on the
masses of pollen, which were as large as a thick kidney bean, and
occupied nearly half the cell. The larvæ (Fig. 21) resemble those of the
Humble bee, but are slenderer, tapering more rapidly towards each end of
the body.
The habits and structure of the little green Ceratina ally it closely
with Xylocopa. This pretty bee, named Ceratina dupla by Mr. Say, tunnels
out the stems of the elder or blackberry, syringa, or any pithy shrub,
excavating them often to a depth of six or seven inches. She makes the
walls just wide enough to admit her body, and of a depth capable of
holding three or four, often five or six cells (Fig. 22). The finely
built cells, with their delicate silken walls, are cylindrical and
nearly square at each end, though the free end of the last cell is
rounded off. They are four and a half tenths of an inch long, and a
little over one-third as broad. The bee places them at nearly equal
distances apart, the slight interval between them being filled in with
dirt.
[Illustration: 22. Nest of Ceratina.]
Dr. T. W. Harris states that May 15, 1832, one female laid its eggs in
the hollow of an aster stalk. Three perfect insects were disclosed from
it July 28th. The observations of Mr. Angus, who saw some bees making
their cells May 18th, also confirm this account. The history of our
little upholsterer is thus cleared up. Late in the spring she builds her
cells, fills them with pollen, and lays one or more eggs upon each mass.
Thus in about two months the insect completes its transformations;
within this period passing through the egg, the larva and chrysalid
states, and then, as a bee, living a few days more, if a male; or if a
female, living through the winter. Her life thus spans one year.
The larva (Fig. 23) is longer than that of Megachile, and compared with
that of Xylocopa, the different segments are much more convex, giving a
serrate outline to the back of the worm. The pupa, or chrysalis, we have
found in the cells the last of July. It is white, and three-tenths of an
inch long. It differs from that of the Leaf-cutter bee in having four
spines on the end of the body.
[Illustration: 23. Larva of Ceratina.]
[Illustration: 24. Nest of Tailor Bee.]
In none of the wild bees are the cells constructed with more nicety than
those of our little Ceratina. She bores out with her jaws a long deep
well just the size of her body, and then stretches a thin, delicate
cloth of silk drawn tight as a drum-head across each end of her
chambers, which she then fills with a mixture of pollen and honey.
[Illustration: 25. Tailor Bee.]
Her young are not, in this supposed retreat, entirely free from danger.
The most invidious foes enter and attack the brood. Three species of
Ichneumon flies, two of which belong to the Chalcid family, lay their
eggs within the body of the larva, and emerge from the dried larva and
pupa skins of the bee, often in great numbers. The smallest parasite,
belonging to the genus Anthophorabia, so called from being first known
as a parasite on another bee (Anthophora), is a minute species found
also abundantly in the tight cells of the Leaf-cutter bee.
The interesting habits of the Leaf-cutting, or Tailor bee (Megachile),
have always attracted attention. This bee is a stout, thick-bodied
insect, with a large, square head, stout, sharp, scissors-like jaws, and
with a thick mass of stout, dense hairs on the under side of the tail
for carrying pollen, as she is not provided with the pollen-basket of
the Honey and Humble bees.
The Megachile lays its eggs in burrows in the stems of the elder (Fig.
24), which we have received from Mr. James Angus; we have also found
them in the hollows of the locust tree. Mr. F. W. Putnam thus speaks of
the economy of M. centuncularis, our most common species. "My attention
was first called, on the 26th of June, to a female busily engaged in
bringing pieces of leaf to her cells, which she was building under a
board, on the roof of the piazza, directly under my window. Nearly the
whole morning was occupied by the bee in bringing pieces of leaf from a
rose bush growing about ten yards from her cells, returning at intervals
of a half minute to a minute with the pieces, which she carried in such
a manner as not to impede her steps when she alighted near her hole."
When the Leaf-cutter bee wishes to cut out a piece of a leaf (Fig. 25)
she alights upon the leaf, and in a few seconds swiftly runs her
scissors-like jaws around through it, bearing off the piece in her hind
legs. "About noon she had probably completed the cell, upon which she
had been engaged, as, during the afternoon, she was occupied in bringing
pollen, preparatory to laying her single egg in the cell. For about
twenty days the bee continued at work, building new cells and supplying
them with pollen.... On the 28th of July, upon removing the board, it
was found that the bee had made thirty cells, arranged in nine rows of
unequal length, some being slightly curved to adapt them to the space
under the board. The longest row contained six cells, and was two and,
three-quarters inches in length; the whole leaf structure being equal to
a length of fifteen inches. Upon making an estimate of the pieces of
leaf in this structure, it was ascertained that there must have been at
least a thousand pieces used. In addition to the labor of making the
cells, this bee, unassisted in all her duties, had to collect the
requisite amount of pollen (and honey?) for each cell, and lay her eggs
therein, when completed. Upon carefully cutting out a portion of one of
the cells, a full-grown larva was seen engaged in spinning a slight
silken cocoon about the walls of its prison, which were quite hard and
smooth on the inside, probably owing to the movements of the larva, and
the consequent pressing of the sticky particles to the walls. In a short
time the opening made was closed over by a very thin silken web. The
cells, measured on the inside of the hard walls, were .35 of an inch in
length, and .15 in diameter. The natural attitude of the larva is
somewhat curved in its cell, but if straightened, it just equals the
inside length of the cell. On the 31st of July, two female bees came
out, having cut their way through the sides of their cells." In three
other cells "several hundred minute Ichneumons (Anthophorabia
megachilis) were seen, which came forth as soon as the cells were
opened."
The habits of the little blue or green Mason bees (Osmia) are quite
varied. They construct their cells in the stems of plants, and in rotten
posts and trees, or, like Andrena, they burrow in sunny banks. A
European species selects snail shells for its nest, wherein it builds
its earthen cells, while other species nidificate under stones. Curtis
found two hundred and thirty cocoons of a British species (Osmia
paretina), placed on the under side of a flat stone, of which one-third
were empty. Of the remainder, the most appeared between March and June,
males appearing first; thirty-five more bees were developed the
following spring. Thus there were three successive broods, for three
succeeding years, so that these bees lived three years before arriving
at maturity. This may partly account for _insect years_, which are like
"apple years," seasons when bees and wasps, as well as other insects,
abound in unusual numbers.
[Illustration: 26. Nest of Osmia.]
Mr. G. R. Waterhouse, in the Transactions of the Entomological Society
of London, for 1864, states that the cells of Osmia leucomelana "are
formed of mud, and each cell is built separately. The female bee,
having deposited a small pellet of mud in a sheltered spot between some
tufts of grass, immediately begins to excavate a small cavity in its
upper surface, scraping the mud away from the centre towards the margin
by means of her jaws. A small, shallow mud-cup is thus produced. It is
rough and uneven on the outer surface, but beautifully smooth on the
inner. On witnessing thus much of the work performed, I was struck with
three points: first, the rapidity with which the insect worked;
secondly, the tenacity with which she kept her original position whilst
excavating; and thirdly, her constantly going over work which had
apparently been completed.... The lid is excavated and rendered concave
on its outer or upper surface, and is convex and rough on its inner
surface; and, in fact, is a simple repetition of the first-formed
portion of the cell, a part of a hollow sphere."
The largest species of Osmia known to us is a very dark-blue species (O.
lignivora). We are indebted to a lady for specimens of the bees with
their cells, which had been excavated in the interior of a maple tree
several inches from the bark. The bee had industriously tunnelled out
this elaborate burrow (Fig. 26), and, in this respect, resembled the
habits of the Carpenter bee more closely than any other species of its
genus.
The tunnel was over three inches long, and about three-tenths of an inch
wide. It contracted a little in width between the cell, showing that the
bee worked intelligently, and wasted no more of her energies than was
absolutely necessary. The burrow contained five cells, each half an inch
long, being rather short and broad, with the hinder end rounded, while
the opposite end, next to the one adjoining, is cut off squarely. The
cell is somewhat jug-shaped, owing to a slight constriction just behind
the mouth. The material of which the cell is composed is stout, silken,
parchment-like, and very smooth within. The interstices between the
cells are filled in with rather coarse chippings made by the bee.
The bee cut its way out of the cells in March, and lived for a month
afterwards on a diet of honey and water. It eagerly lapped up the drops
of water supplied by its keeper, to whom it soon grew accustomed, and
seemed to recognize.
Our smallest and most abundant species is the little green Osmia
simillima. It builds its little oval, somewhat urn-shaped cells against
the roof of the large deserted galls of the oak-gall fly (Diplolepis
confluentus), placing them, in this instance eleven in number, in two
irregular rows, from which the mature bees issue through a hole in the
gall (Fig. 27, with two separate cells). The earthen cells, containing
the tough dense cocoons, were arranged irregularly so as to fit the
concave vault of the larger gall, which was about two inches in
diameter. On emerging from the cell the Osmia cuts out with its powerful
jaws an ovate lid, nearly as large as one side of the cell.
[Illustration: 27. Nest of Osmia in a gall.]
In the Harris collection are the cells and specimens of Osmia pacifica,
the peaceful Osmia, which, according to the manuscript notes of Dr.
Harris, is found in the perfect state in earthen cells beneath stones.
The cell is oval cylindrical, a little contracted as usual with those of
all the species of the genus, thus forming an urn-shaped cell. It is
half an inch long, and nearly three-tenths of an inch wide, while the
cocoon, which is rather thin, is three-tenths of an inch long. We are
not acquainted with the habits of the larva and pupa in this country,
but Mr. F. Smith states that the larva of the English species hatches in
eight days after the eggs are laid, feeds ten to twelve days, when it
becomes full-grown, then spins a thin silken covering, and remains in an
inactive state until the following spring, when it completes its
transformations.
In the economy of our wild bees we see the manifestation of a wonderful
instinct, as well as the exhibition of a _limited reason_. We can
scarcely deny to animals a kind of reason which apparently differs _only
in degree_ from that of man. Each species works in a sphere limited by
physical laws, but within that sphere it is a free agent. They have
enough of instinct and reason to direct their lives, and to enable them
to act their part in carrying out the plan of creation.
[Illustration: Paper Wasp.]
FOOTNOTES:
[Footnote 1: The cells are not perfectly hexagonal. See the studies on
the formation of the cells of the bee, by Professor J. Wyman, in the
Proceedings of the American Academy of Arts and Sciences, Boston, 1866;
and the author's Guide to the Study of Insects, p 123.]
[Footnote 2: Notes on the Habits of the Humble Bee (Proceedings of the
Essex Institute, vol. iv, 1864, p. 101).
Mr. Angus also writes us as follows concerning the habits of the
Wandering Humble bee (Bombus vagans): "I have found the males plentiful
near our garden fence, within a hole such as would be made by a mouse.
They seem to be quite numerous. I was attracted to it by the noise they
were making in fanning at the opening. I counted at one time as many as
seven thus employed, and the sound could be heard several yards off.
Several males were at rest, but mostly on the wing, when they would make
a dash among the fanners, and all would scatter and play about. The
workers seem to be of a uniform size, and full as large as the males. I
think the object of the fanning was to introduce air into the nest, as
is done by the Honey bees."]
[Footnote 3: "Since writing the above I have opened one of the new holes
of Xylocopa, which was commenced between three and four weeks ago, in a
pine slat used in the staging of the greenhouse. The dimensions were as
follows:--Opening fully 3-8 wide; depth 7-16; whole length of tunnel 6
5-16 inches. The tunnel branched both ways from the hole. One end, from
opening, was 2 5-8, containing three cells, two with larva and pollen,
the third empty. The other side of the opening, or the rest of the
tunnel, was empty, with the exception of the old bee (only one) at work.
I think this was the work of one bee, and, as near as I can judge, about
twenty-five days' work. Width of tunnel inside at widest 9-16 inch.
"I have just found a Xylocopa bobbing at one of the holes, and in order
to ascertain the depth of the tunnel, and to see whether there were any
others in them, I sounded with a pliable rod, and found others in one
side, at a depth of five and one half inches; the other side was four
inches deep without bees. The morning was cool, so that the object in
bobbing could not have been to introduce fresh currents of air, but must
have had some relation to those inside. Their legs on such occasions
are, as I have noticed, loaded with pollen."]
CHAPTER II.
THE HOME OF THE BEES.
[_Concluded._]
While the Andrena and Halictus bees, whose habits we now describe, are
closely allied in form to the Hive bee, socially they are the
"mud-sills" of bee society, ranking among the lowest forms of the family
of bees. Their burrowing habits ally them with the ants, from whose
nests their own burrows can scarcely be distinguished. Their economy
does not seem to demand the exercise of so much of a true reasoning
power and pliable instinct as characterizes bees, such as the Honey and
Humble bee, which possess a high architectural skill. Moreover they are
not social; they have no part in rearing and caring for their young, a
fact that lends so much interest to the history of the Hive and Humble
bee. In this respect they are far below the wasps, a family belonging
next below in the system of Nature.
A glance at the drawing (Fig. 28), of a burrow, with its side galleries,
of the Andrena vicina, reveals the economy of one of our most common
forms. Quite early in spring, when the sun and vernal breezes have dried
up the soil, and the fields exchange their rusty hues for the rich green
verdure of May, our Andrena, tired of its idle life among the blossoms
of the willow, the wild cherry, and garden flowers, suddenly becomes
remarkably industrious, and wields its spade-like jaws and busy feet
with a strange and unwonted energy. Choosing some sunny, warm, grassy
bank (these nests were observed in the "great pasture" of Salem), not
always with a southern exposure however, the female sinks her deep well
through the sod from six inches to a foot into the sandy soil beneath.
She goes to work literally tooth and nail. Reasoning from observations
made on several species of wasps, and also from studying the structure
of her jaws and legs, it is evident that she digs in and loosens the
soil with her powerful jaws, and then throws out the dirt with her legs.
She uses her fore legs like hands, to pass the load of dirt to her hind
legs, and then runs backward out of her hole to dump it down behind her.
Mr. Emerton tells me that he never saw a bee in the act of digging but
once, and then she left off after a few strokes. He also says, "they are
harmless and inoffensive. On several occasions I have lain on the grass
near their holes for hours, but not one attempted to sting me; and when
taken between the fingers, they make but feeble resistance."
[Illustration: Fig. 28.
Nest (natural size) of Andrena vicina, showing the main burrow, and the
cells leading from it; the oldest cell containing the pupa (_a_) is
situated nearest the surface, while those containing the larva (_b_) lie
between the pupa and the cell (_e_) containing the pollen mass and egg
resting upon it. The most recent cell (_f_) is the deepest down, and
contains a freshly deposited pollen mass. At _c_ is the beginning of a
cell; _g_, level of the ground.]
To enter somewhat into detail, we gather from the observations of Mr.
Emerton (who has carefully watched the habits of these bees through
several seasons) the following account of the economy of this bee: On
the 4th of May the bees were seen digging their holes, most of which
were already two inches deep, and one, six inches. The mounds of earth
were so small as to be hardly noticed. At this time an Oil beetle was
seen prowling about the holes. The presence of this dire foe of Andrena
at this time, it will be seen in a succeeding chapter on the enemies of
the bees, is quite significant. By the 15th of May, hundreds of Andrena
holes were found in various parts of the pasture, and at one place, in a
previous season, there were about two hundred found placed within a
small area. One cell was dug up, but it contained no pollen. Four days
later, several Andrenas were noticed resting from their toil at the
opening of their burrows. On the 28th of May, in unearthing six holes,
eight cells were found to contain pollen, and in two of them a small
larva. The pellets of pollen are about the size of a small pea. They are
hard and round at first, before the young has hatched, but as the larva
grows, the mass becomes softer and more pasty, so that the larva buries
its head in the mass, and greedily sucks it in. When is the pollen
gathered by the bee and kneaded into the pellet-like mass? On July 4th,
a cell was opened in which was a bee busily engaged preparing the
pollen, which was loosely and irregularly piled up, while there was a
larva in an adjoining cell nearly half an inch long. It would seem,
then, that the bee comes in from the fields laden with her stores of
pollen, which she elaborates into bee bread within her cell.
When the bee returns to her cell she does not directly fly towards the
entrance, since, as was noticed in a particular instance, she flew about
for a long time in all directions without any apparent aim, until she
finally settled near the hole, and walked into her subterranean retreat.
On a rainy day, May 24th, our friend visited the colony, but found no
bees flying about the holes. The little hillocks had been beaten down by
the pitiless raindrops, and all traces of their industry effaced. On
digging down, several bees were found, indicating that on rainy days
they seek the shelter of their holes, and do not take refuge under
leaves of the plants they frequent.
On the 29th of June, six full-grown larvæ were exhumed, and one, about
half grown. On the 20th of July, the colony seemed well organized, as,
on laying open a burrow at the depth of six inches, he began to find
cells. The upper ones, to the number of a dozen, were deserted and
filled with earth and grass roots, and had evidently been built and used
during the previous year. Below these were eight cells placed around the
main vertical gallery, reaching down to the depth of thirteen inches,
and all containing nearly full-grown larvæ of the bees, or else those of
some parasitic bee (Nomada) which had devoured the food prepared for the
young Andrena.
About the first of August the larva transforms to a pupa or chrysalis,
as at this time two pupæ were found in cells a foot beneath the surface.
As shown in the cut, those cells situated lowest down seem to be the
last to have been made, while the eggs laid in the highest are the first
to hatch, and the larvæ disclosed from them, the first to change to
pupæ. Four days later the pupæ of Cuckoo bees (Nomada) were found in the
cells. No Andrenas were seen flying about at this time.
On the 24th of August, to be still very circumstantial in our narrative
though at the risk of being tedious, three burrows were unearthed, and
in them three fully formed bees were found nearly ready to leave their
cells, and in addition several pupæ. In some other cells there were
three of the parasitic Nomada also nearly ready to come out, which
seemed to be identical with some bees noticed playing very innocently
about the holes early in the summer.
On the last day of August, very few of the holes were open. A number of
Oil beetles were strolling suspiciously about in the neighborhood, and
some little black Ichneumon flies were seen running about among the
holes.
During mid-summer the holes were found closed night and day by clods of
earth.
The burrow is sunken perpendicularly, with short passages leading to the
cells, which are slightly inclined downwards and outwards from the main
gallery. The walls of the gallery are rough, but the cells are lined
with a mucous-like secretion, which, on hardening, looks like the
glazing of earthenware. This glazing is quite hard, and breaks up into
angular pieces. It is evidently the work of the bee herself, and is not
secreted and laid on by the larva. The diameter of the interior of the
cell is about one-quarter of an inch, contracting a little at the mouth.
When the cell is taken out, the dirt adheres for a line in thickness, so
that it is of the size and form of an acorn.
The larva of Andrena (Fig. 29) is soft and fleshy, like that of the
Honey bee. Its body is flattened, bulging out prominently at the sides,
and tapering more rapidly than usual towards each end of the body. The
skin is very thin, so that along the back the heart or dorsal vessel may
be distinctly seen, pulsating about sixty times a minute.
Our cut (Fig. 28, _a_) also represents the pupa, or chrysalis, as seen
lying in its cell. The limbs are folded close to the body in the most
compact way possible. On the head of the semi-pupa, _i.e._, a transition
state between the larva and pupa, there are two prominent tubercles
situated behind the simple eyes, or ocelli; these are deciduous organs,
apparently aiding the insect in moving about its cell. They disappear in
the mature pupa.
[Illustration: Fig. 29. Fig. 30. Fig. 31.
Fig. 31. Larva of Halictus parallelus.
Fig. 29. Larva of Andrena vicina.
Fig. 30. Pupa of Halictus parallelus seen from beneath.]
To those accustomed to rearing butterflies, and seeing the chrysalis at
once assuming its perfected shape, after the caterpillar skin is thrown
off, it may seem strange to hear one speak of a "half-pupa," and of
stages intermediate between the larva and pupa. But the external changes
of form, though rapidly passed through, consisting apparently of a mere
sloughing off of the outer skin, are yet preceded by slow and very
gradual alterations of tissues, resulting from the growth of cells. An
inner layer of the larva-skin separates from the outer, and, by changes
in the form of the muscles, is drawn into different positions, such as
is assumed by the pupa, which thus lies concealed beneath the
larva-skin. But a slight alteration is made in the general form of the
larva, consisting mostly of an enlargement of the thoracic segments,
which is often overlooked, even by the special student, though of great
interest to the philosophic naturalist.
From Mr. Emerton's observations we should judge that the pupa state
lasted from three to four weeks, as the larvæ began to transform the
first of August, and appeared during the last week of the same month as
perfect bees.
The Andrena is seen as late as the first week in September, and again
early in April, about the flowers of the willow. It is one of the
largest of its genus and a common species.
Having, in a very fragmentary way, sketched the life history of our
Andrena and had some glimpses of its subterranean life, let us now
compare with it another genus of solitary bee (Halictus), quite closely
allied in all respects, though a little lower in the scale.
The Halictus parallelus excavates cells almost exactly like those of
Andrena; but since the bee is smaller, the holes are smaller, though as
deep. Mr. Emerton found one nest in a path a foot in depth. Another
nest, discovered September 9th, was about six inches deep. The cells are
in form like those of Andrena, and like them, are glazed within. The egg
is rather slenderer and much curved; in form it is long, cylindrical,
obtuse at one end, and much smaller at the other. The larva (Fig. 31) is
longer and slenderer, being quite different from the rather broad and
flattened larva of Andrena. The body is rather thick behind, but in
front tapers slowly towards the head, which is of moderate size. Its
body is somewhat tuberculated, the tubercle aiding the grub in moving
about its cell. Its length is nearly one-half (.40) of an inch. On the
pupa are four quite distinct conical tubercles forming a transverse line
just in front of the ocelli; and there are also two larger, longer
tubercles, on the outer side of each of which, an ocellus is situated.
Figure 30 represents the pupa seen from beneath.
Search was made on July 16th, where the ground was hard as stone for six
inches in depth, below which the soil was soft and fine, and over twenty
cells were dug out. "The upper cells contained nearly mature pupæ, and
the lower ones, larvæ of various sizes, the smallest being hardly
distinguishable by the naked eye. Each of these small larvæ was in a
cell by itself, and situated upon a lump of pollen, which was the size
and shape of a pea, and was found to lessen in size as the larva grew
larger. These young were probably the offspring of several females, as
four mature bees were found in the hole." The larva of an English
species hatches in ten days after the eggs are laid.
Another brood of bees appeared the middle of September, as on the ninth
of that month (1864) Mr. Emerton found several holes of the same species
of bee, made in a hard gravel road near the turnpike. When opened, they
were found to contain several bees with their young. September 2nd, of
this year, the same kind of bee was found in holes, and just ready to
leave the cell. It is probable that these bees winter over.
We have incidentally noticed the presence in the nests of Andrena and
Halictus of a stranger bee, clad in gay, fantastic hues, which lives a
parasitic life on its hosts. This parasitism does not go far enough to
cause the death of the host, since we find the young of the parasitic
Cuckoo bee, in cells containing the young of the former.
Mr. F. Smith, in his "Catalogue of British Bees," says of this genus:
"No one appears to know anything beyond the mere fact of their entering
the burrows of Andrenidæ and Apidæ, except that they are found in the
cells of the working bees in their perfect condition: it is most
probable that they deposit their eggs on the provision laid up by the
working bee, that they close up the cell, and that the working bee,
finding an egg deposited, commences a fresh cell for her own progeny."
He has, however, found two specimens of Nomada, sexfasciata in the cells
of the long-horned bee, Eucera longicornis. He also states, that while
some species are constant in their attacks on certain Halicti and
Andrenæ, others attack different species of these genera
indiscriminately. In like manner another Cuckoo bee (Coelioxys) is
parasitic on Megachile and Saropoda; Stelis is a parasite on Osmia, the
Mason bee: and Melecta infests the cells of Anthophora.
The observations of Mr. Emerton enable us still further to clear up the
history of this obscure visitor. He found both the larva and pupa, as
well as the perfect bee, in the cells of both genera; so that either
both kinds of bee, when hatched from eggs laid in the same cell, feed on
the same pollen mass, which therefore barely suffices for the
nourishment of both; or the hostess, discovering the strange egg laid,
cuckoo-like, in her own nest, has the forethought to deposit another
ball of pollen to secure the safety of her young.
Is such an act the operation of a blind instinct? Does it not rather
ally our little bee with those higher animals which undoubtedly possess
a reasoning power? Its _instinct_ teaches it to build cells, and prepare
its pollen mass, and lay an egg thereon. Its _reason_ enables it, in
such an instance as this, when the life of the brood is threatened, to
guard against any such danger by means to which it does not habitually
resort. This instance is paralleled by the case of our common summer
Yellow bird, which, on finding an egg of the Cow bunting in its nest,
often builds a new nest above it, to the certain destruction of the
unwelcome egg in the nest beneath.
In the structure of the bee, and in all its stages of growth, our
parasite seems lower in the zoölogical scale than its host. It is
structurally a degraded form of Working-bee, and its position socially
is unenviable. It is lazy, not having the provident habits of the
Working-bees; it aids not in the least, so far as we know, the
cross-fertilization of plants--one great office in the economy of nature
which most bees perform,--since it is not a pollen-gatherer, but on the
contrary is seemingly a drag and hinderance to the course of nature. But
yet nature kindly, and as if by a special interposition, provides for
its maintenance, and the humble naturalist can only exclaim, "God is
great, and his ways mysterious," and go on studying and collecting
facts, leaving to his successors the more difficult task, but greater
joy of discovering the cause and reason of things that are but a puzzle
to the philosophers of this day.
The larva of Nomada may be known from those of its host, by its
slenderer body and smaller head, while the body is smoother and more
cylindrical. Both sexes of Nomada imbricata and N. pulchella were found
by Mr. Emerton, the former in both the Andrena and Halictus nests, and
both were found in a single Andrena nest.
[Illustration: Wood Wasp.]
CHAPTER III.
THE PARASITES OF THE HONEY BEE.
Very few bee-keepers are probably aware how many insect parasites infest
the Honey bee. In our own literature we hear almost nothing of this
subject, but in Europe much has been written on bee parasites. From Dr.
Edward Assmuss' little work on the "Parasites of the Honey Bee," we
glean some of the facts now presented, and which cannot fail to interest
the general reader as well as the owner of bees.
The study of the habits of animal parasites has of late gained much
attention among naturalists, and both the honey and wild bees afford
good examples of the singular relation between the host and the
parasites which live upon it. Among insects generally, there are certain
species which devour the contents of the egg of the victim. Others, and
this is the most common mode of parasitism, attack the insect in its
larva state; others, in the pupa state, and still others in the perfect,
or imago state. Dr. Leidy has shown that the wood-devouring species of
beetle, Passalus cornutus, and some Myriopods, or "thousand legs," are,
in some cases, tenanted by myriads of microscopic plants and worms which
luxuriate in the alimentary canal, while the "caterpillar-fungus"
attacks sickly caterpillars, filling out their bodies, and sending out
shoots into the air, so that the insect looks as if transformed into a
vegetable.
The Ichneumon flies, of which there are undoubtedly several thousand
species in this country, are the most common insect parasites. Next to
these are the different species of Tachina and its allied genera. These,
like Ichneumons, live in the bodies of their hosts, consuming the fatty
parts, and finishing their transformations just as the exhausted host
is ready to die, issue from their bodies as flies, closely resembling
the common housefly.
A small fly has been found in Europe to be the most formidable foe of
the hive bee, sometimes producing the well-known disease called
"foul-brood," which is analogous to the typhus fever of man.
[Illustration: 32. Phora and its Young.]
This fly, belonging to the genus Phora (Fig. 32, Phora incrassata; _a_,
larva; _b_, puparium; _c_, another species from Mammoth Cave), is a
small insect about a line and a half long, and found in Europe during
the summer and autumn flying slowly about flowers and windows, and in
the vicinity of beehives. Its white, transparent larva is cylindrical, a
little pointed before, but broader behind. The head is small and
rounded, with short, three-jointed antennæ, and at the posterior end of
the body are several slender spines. The puparium, or pupa case,
inclosing the delicate chrysalis, is oval, consisting of eight segments,
flattened above, with two large spines near the head, and four on the
extremity of the body.
When impelled by instinct to provide for the continuance of its species,
the Phora enters the beehive and gains admission to a cell, when it
bores with its ovipositor through the skin of the bee larva, laying its
long oval egg in a horizontal position just under the skin. The embryo
of the Phora is already well developed, so that in three hours after the
egg is inserted in the body of its unsuspecting and helpless host, the
embryo is nearly ready to hatch. In about two hours more it actually
breaks off the larger end of the egg-shell and at once begins to eat the
fatty tissues of its victim, its posterior half still remaining in the
shell. In an hour more, it leaves the egg entirely and buries itself
completely in the fatty portion of the young bee.
The maggot moults three times. In twelve hours after the last moult it
turns around with its head towards the posterior end of the body of its
host, and in another twelve hours, having become full-fed, it bores
through the skin of the young, eats its way through the brood-covering
of the cell and falls to the bottom of the hive, where it changes to a
pupa in the dust and dirt, or else creeps out of the door and transforms
in the earth. Twelve days after, the fly appears.
The young bee, emaciated and enfeebled by the attacks of its ravenous
parasite, dies, and its decaying body fills the bottom of the cell with
a slimy, foul-smelling mass, called "foul-brood." This gives rise to a
miasma which poisons the neighboring brood, until the contagion (for the
disease is analogous to typhus, jail or ship-fever) spreads through the
whole hive, unless promptly checked by removing the cause and thoroughly
cleansing the hive.
Foul-brood sometimes attacks our American hives, and, though the cause
may not be known, yet from the hints given above we hope to have the
history of our species of Phora cleared up, should our disease be found
to be sometimes due to the attacks of such a parasitic fly.
[Illustration: 33. Bee Louse and Larva.]
We figure the Bee louse of Europe (Fig. 33 b, Braula cæca), which is a
singular wingless spider-like fly, allied to the wingless Sheep tick
(Melophagus), the wingless Bat tick (Nycteribia) and the winged Horse
fly (Hippobosca). The head is very large, without eyes or ocelli (simple
eyes), while the ovate hind-body consists of five segments, and is
covered with stiff hairs. It is one-half to two-thirds of a line long.
This spider fly is "pupiparous," that is, the young, of which only a
very few are produced, is not born until it has assumed the pupa state
or is just about to do so. The larva (Fig. 33 _a_) is oval,
eleven-jointed, and white in color. The very day it is hatched, it sheds
its skin and changes to an oval puparium of a dark brown color.
Its habits resemble those of the flea. Indeed, should we compress its
body strongly, it would bear a striking resemblance to that insect. It
is evidently a connecting link between the flea, and the two winged
flies. Like the former it lives on the body of its host, and obtains its
food by plunging its stout beak into the bee and sucking its blood.
It has not been noticed in this country, but is liable to be imported on
the bodies of Italian bees. Generally, one or two of the Braulas may, on
close examination, be detected on the body of the bee; sometimes the
poor bees are loaded down by as many as a hundred of these hungry
blood-suckers. Assmuss recommends rubbing them off with a feather, as
the bee goes in and out of the door of its hive.
[Illustration: 34. Hive Trichodes.]
Among the beetles are a few forms occasionally found in bees' nests and
also parasitic on the body of the bee. Trichodes apiarius (Fig. 34, _a_,
larva; _b_, pupa, front view) has long been known in Europe to attack
the young bees. In its perfect, or beetle state it is found on flowers,
like our Trichodes Nuttallii, which is commonly found on the Spiræa in
August, and which may yet prove to enter our beehives. The larva devours
the brood, but with the modern hive its ravages may be readily detected.
[Illustration: 35. Meloë.]
The Oil beetle, Meloë angusticollis (Fig. 35, male, differing from the
female by having the antennæ as if twisted into a knot; Fig. 36, the
active larva found on the body of the bee), is a large dark blue insect
found crawling in the grass in the vicinity of the nests of Andrena,
Halictus, and other wild bees in May, and again in August and
September. The eggs are laid in a mass covered with earth at the root
of some plant. During April and early in May, when the willows are in
blossom, we have found the young recently hatched larvæ in considerable
abundance creeping briskly over the bees, or with their heads plunged
between the segments of the body, greedily sucking in the juices of
their host. Those that we saw occurred on the Humble and other wild
bees, and on various flies (Syrphus and Muscidæ), and there is no reason
why they should not infest the Honey bee, which frequents similar
flowers, as they are actually known to do in Europe. These larvæ are
probably hatched out near where the bees hibernate, so as to creep into
their bodies before they fly in the spring, as it would be impossible
for them to crawl up a willow tree ten feet high or more, their feet
being solely adapted for climbing over the hairy body of the bee, which
they do not leave until about to undergo their strange and unusual
transformations.
[Illustration: Early Stages of Meloë.]
In Europe, Assmuss states that on being brought into the nest by the
bee, they leave the bee and devour the eggs in the bee cells, and then
attack the bee bread. When full-fed and ready to pass through their
transformations to attain the beetle state, instead of at once assuming
the pupa and imago forms, as in the Trichodes represented in fig. 34,
they pass through a _hyper-metamorphosis_, as Fabre, a French
naturalist, calls it. In other words, the changes in form which are
preparatory to assuming the pupa and imago states are more marked and
almost coequal with the larva and pupa states, so that the Meloë,
instead of passing through three states (the egg, larva and pupa), in
realty passes through these and two others in addition, which are
intermediate. The whole subject of the metamorphosis of this beetle
needs revision, but Fabre states that the larva, soon after entering the
nest of its host, changes its skin and assumes a second larva form.
Newport, who with Siebold has carefully described the metamorphoses of
Meloë, does not mention this stage in its development, which Fabre calls
"pseudo-chrysalis." It is motionless, the head is mask-like, without
movable appendages, and the feet are represented by six tubercles. This
is more properly speaking the semi-pupa, and the mature pupa grows
beneath its mask-like form, which is finally moulted. This form,
however, according to Fabre, changes its skin and turns into a third
larva form (Fig. 37). After some time it assumes its true pupa form
(Fig. 38), and finally moults this skin to appear as a beetle.
Fabre has also, in a lively and well-written account, given a history of
Sitaris, a European beetle, somewhat resembling Meloë. He states that
Sitaris lays its eggs near the entrance of bees' nests, and at the very
moment that the bee lays her egg in the honey cell, the flattened, ovate
Sitaris larva drops from the body of the bee upon which it has been
living, and feasts upon the contents of the freshly laid egg. After
eating this delicate morsel it devours the honey in the cells of the bee
and changes into a white, cylindrical, nearly footless grub, and after
it is full-fed, and has assumed a supposed "pupa" state, the skin,
without bursting, incloses a kind of hard "pupa" skin, which is very
similar in outline to the former larva, within whose skin is found a
whitish larva which directly changes into the true pupa. In a succeeding
state this pupa in the ordinary way changes to a beetle which belongs to
the same group of Coleoptera as Meloë. We cannot but think, from
observations made on the humble bee, the wasp, two species of moths and
several other insects, that this "hyper-metamorphosis" is not so
abnormal a mode of insect metamorphosis as has been supposed, and that
the changes of these insects, made beneath the skin of the mature larva
before assuming the pupa state, are almost as remarkable as those of
Meloë and Sitaris, though less easily observed than they. Several other
beetles allied to Meloë are known to be parasitic on wild bees, though
the accounts of them are fragmentary.
THE STYLOPS PARASITE.
The history of Stylops, a beetle allied to Meloë, is no less strange
than that of Meloë, and is in some respects still more interesting. On
June 18th I captured an Andrena vicina which had been "stylopized." On
looking at my capture I saw a pale reddish-brown triangular mark on the
bee's abdomen; this was the flattened head and thorax of a female
Stylops (Fig. 39_a_, position of the female of Stylops, seen in profile
in the abdomen of the bee; Fig. 39_b_, the female seen from above. The
head and thorax are soldered into a single flattened mass, the baggy
hind-body being greatly enlarged like that of the gravid female of the
white ant, and consisting of nine segments).
[Illustration: 39. Female Stylops.]
On carefully drawing out the whole body (Pl. 1, Fig. 6, as seen from
above, and showing the alimentary canal ending in a blind sac; Fig.
6_a_, side view), which is very extensible, soft and baggy, and
examining it under a high power of the microscope, we saw multitudes, at
least several hundred, of very minute larvæ, like particles of dust to
the naked eye, issuing in every direction from the body of the parent
now torn open in places, though most of them made their exit through an
opening on the under side of the head-thorax. The Stylops, being hatched
while still in the body of the parent, is, therefore viviparous. She
probably never lays eggs.
On the last of April, when the Mezereon was in blossom, I caught the
singular looking male (Stylops Childreni, Fig. 40; a, side view; it is
about one-fourth of an inch long), which was as unlike its partner as
possible. I laid it under a tumbler, when the delicate insect flew and
tumbled about till it died of exhaustion in a few hours.
It appears, then, that the larvæ are hatched during the middle or last
of June from eggs fertilized in April. The larvæ then crawl out upon the
body of the bee, on which they are transported to the nest, where they
enter, according to Peck's observations, the body of the larva, on whose
fatty parts they feed. Previous to changing to a pupa the larva lives
with its head turned towards that of its host, but before assuming the
perfect state (which they do in the late summer or autumn) it must
reverse its position. The female protrudes the front part of her body
between the segments of the abdomen of her host, as represented in our
figure. This change, Newport thinks, takes place after the bee-host has
undergone its metamorphoses, though the bee does not leave her earthen
cells until the following spring. Though the male Stylops deserts his
host, his wingless partner is imprisoned during her whole life within
her host, and dies immediately after giving birth to her myriad (for
Newport thinks she produces over two thousand) offspring.
[Illustration: 40. Male Stylops.]
Xenos Peckii, an allied insect, was discovered by Dr. Peck to be
parasitic in the body of wasps, and there are now known to be several
species of this small but curious family, Stylopidæ, which are known to
live parasitically on the bodies of our wild bees and wasps. The
presence of these parasites finally exhausts the host, so that the
sterile female bee dies prematurely.
As in the higher animals, bees are afflicted with parasitic worms which
induce disease and sometimes death. The well-known hair worm, Gordius,
is an insect parasite. The adult form is about the size of a slender
knitting needle, and is seen in moist soil and in pools. It lays,
according to Dr. Leidy, "millions of eggs connected together in long
cords." The microscopical, tadpole-shaped young penetrate into the
bodies of insects frequenting damp localities. Fairly ensconced within
the body of their unsuspecting host, they luxuriate on its fatty
tissues, and pass through their metamorphoses into the adult form, when
they desert their living house and take to the water to lay their eggs.
In Europe, Siebold has described Gordius subbifurcus, which infests the
drones of the Honey bee, and also other insects. Professor Siebold has
also described Mermis albicans, which is a similar kind of hair worm,
from two to five inches long, and whitish in color. This worm is also
found, strangely enough, only in the drones, though it is the workers
which frequent watery places to appease their thirst.
[Illustration: 41. Bee fungus.]
Thousands of insects are carried off yearly by parasitic fungi. The
ravages of the Muscardine, caused by a minute fungus (Botrytris
Bassiana), have threatened the extinction of silk culture in Europe, and
the still more formidable disease called _pebrine_ is thought to be of
vegetable origin. Dr. Leidy mentions a fungus which must annually carry
off myriads of the Seventeen Year Locust. A somewhat similar fungus,
Mucor mellitophorus (Fig. 41), infests bees, filling the stomach with
microscopical colorless spores, so as greatly to weaken the insect.
As there is a probability that many insects, parasites on the wild bees,
may sooner or later afflict the Honey bee, and also to illustrate
farther the complex nature of insect parasitism, we will for a moment
look at some other bee parasites.
[Illustration: Pl. 1
PARASITES OF BEES.]
Among the numerous insects preying in some way upon the Humble bee are
to be found other species of bees and moths, flies and beetles. Insect
parasites often imitate their host: Apathus (Plate I, Fig. 1, A.
Ashtoni) can scarcely be distinguished from its host, and yet it lives
cuckoo-like in the cells of the Humble bee, though we know not yet how
injurious it really is. Then there are Conops and Volucella, the
former of which lives like Tachina and Phora within the bee's body,
while the latter devours the brood. The young (Plate I, Figs. 5, 5_a_)
of another fly allied to Anthomyia, of which the Onion fly (Fig. 42) is
an example, is also not unfrequently met with. A small beetle (Plate 1.
Fig. 4, Antherophagus ochraceus) is a common inmate of Humble bees'
nests, and probably feeds upon the wax and pollen. We have also found
several larvæ (Fig. 43) of a beetle of which we do not know the adult
form. Of similar habits is probably a small moth (Nephopteryx Edmandsii,
Plate I, Figs. 2; 2_a_, larva; Fig. 2_b_, chrysalis, or pupa) which
undoubtedly feeds upon the waxen walls of the bee cells, and thus, like
the attacks of the common bee moth (Galleria cereana, whose habits are
so well known as not to detain us, must prove very prejudicial to the
well being of the colony. This moth is in turn infested by an Ichneumon
fly (Microgaster nephoptericis, Plate I, Figs. 3, 3_a_) which must prove
quite destructive.
[Illustration: 42. Onion Fly and Maggot.]
[Illustration: 43. Larva of Beetle.]
The figures of the early stages of a minute ichneumon represented on the
same plate (Fig. 7, larva, and 7_a_, pupa, of Anthophorabia megachilis)
which is parasitic on Megachile, the Leaf-cutter bee, illustrates the
transformations of the Ichneumon flies, the smallest species of which
yet known (and we believe the smallest insect known at all) is the
Pteratomus Putnami (Pl. I, Fig. 8, wanting the hind leg), or "winged
atom," which is only one-ninetieth of an inch in length, and is
parasitic on Anthophorabia, itself a parasite. A species of mite (Plate
I, Figs. 9; 9_a_, the same seen from beneath) is always to be found In
humble bees' nests, but it is not thought to be specially obnoxious to
the bees themselves, though several species of mites (Gamasus, etc.) are
known to be parasitic on insects.
CHAPTER IV.
A FEW WORDS ABOUT MOTHS.
The butterflies and moths from their beauty and grace, have always been
the favorites among amateur entomologists, and rare and costly works
have been published in which their forms and gorgeous colors are
represented in the best style of natural history art. We need only
mention the folio volume of Madam Merian of the last century, Harris's
Aurelian, the works of Cramer, Stoll, Drury, Hübner, Horsfield,
Doubleday and Westwood, and Hewitson, as comprising the most luxurious
and costly entomological works.
Near the close of the last century, John Abbot went from London and
spent several years in Georgia, rearing the larger and more showy
butterflies and moths, and painting them in the larva, chrysalis and
adult, or imago stage. These drawings he sent to London to be sold. Many
of them were collected by Sir James Edward Smith, and published under
the title of "The Natural History of the Rarer Lepidopterous Insects of
Georgia, collected from the Observations of John Abbot, with the Plants
on which they Feed." (London, 1797. 2 vols., fol.) Besides these two
rare volumes there are sixteen folio volumes of drawings by Abbot in the
Library of the British Museum. This work is of especial interest to the
American student as it illustrates the early stages of many of our
butterflies and moths.
Indeed the study of insects possesses most of its interest when we
observe their habits and transformations. Caterpillars are always to be
found, and with a little practice are easy to raise; we would therefore
advise any one desirous of beginning the study of insects to take up the
butterflies and moths. They are perhaps easier to study than any other
group of insects, and are more ornamental in the cabinet. As a
scientific study we would recommend it to ladies as next to botany in
interest and in the ease in which specimens may be collected and
examined. The example of Madam Merian, and several ladies in this
country who have greatly aided science by their well filled cabinets,
and critical knowledge of the various species and their transformations,
is an earnest of what may be expected from their followers. Though the
moths are easy to study compared with the bees, flies, beetles and bugs,
and dragon flies, yet many questions of great interest in philosophical
entomology have been answered by our knowledge of their structure and
mode of growth. The great works of Herold on the evolution of a
caterpillar; of Lyonet on the anatomy of the Cossus; of Newport on that
of the Sphinx; and of Siebold on the parthenogenesis of insects, are
proofs that the moths have engaged the attention of some of the master
minds in science.
The study of the transformations of the moths is also of great
importance to one who would acquaint himself with the questions
concerning the growth and metamorphoses and origin of animals. We should
remember that the very words "metamorphosis" and "transformation," now
so generally applied to other groups of animals and used in
philosophical botany, were first suggested by those who observed that
the moth and butterfly attain their maturity only by passing through
wonderful changes of form and modes of life.
The knowledge of the fact that all animals pass through some sort of a
metamorphosis is very recent in physiology. Moreover the fact that these
morphological eras in the life of an individual animal accord most
unerringly with the gradation of forms in the type of which it is a
member, was the discovery of the eminent physiologist Von Baer. Up to
this time the true significance of the luxuriance and diversity of
larval forms had never seriously engaged the attention of systematists
in entomology.
What can possibly be the meaning of all this putting on and taking off
of caterpillar habiliments, or in other words, the process of moulting,
with the frequent changes in ornamentation, and the seeming
fastidiousness and queer fancies and strange conceits of these young and
giddy insects seems hidden and mysterious to human observation. Indeed,
few care to spend the time and trouble necessary to observe the insect
through its transformations; and that done, if only the larva of the
perfect insect can be identified and its form sketched how much was
gained! A truthful and circumstantial biography, in all its relations,
of a single insect has yet to be written!
We should also apply our knowledge of the larval forms of insects to the
details of their classification into families and genera, constantly
collating our knowledge of the early stages with the structural
relations that accompany them in the perfect state.
The simple form of the caterpillar seems to be a concentration of the
characters of the perfect insect, and presents easy characters by which
to distinguish the minor groups; and the relative rank of the higher
divisions will only be definitely settled when their forms and methods
of transformation are thoroughly known. Thus, for example, in two groups
of the large Attacus-like moths, which are so amply illustrated in Dr.
Harris's "Treatise on Insects injurious to Vegetation"; if we take the
different forms of the caterpillars of the Tau moth of Europe, which are
figured by Duponchel and Godard, we find that the very young larva has
four horn-like processes on the front, and four on the back part of the
body. The full grown larva of the Regalis moth, of the Southern and
Middle states, is very similarly ornamented. It is an embryonic form,
and therefore inferior in rank to the Tau moth. Multiply these horns
over the surface of the body, lessen their size, and crown them with
hairs, and we have our Io moth, so destructive to corn. Now take off the
hairs, elongating and thinning out the tubercles, and make up the loss
by the increased size of the worm, and we have the caterpillar of our
common Cecropia moth. Again, remove the naked tubercles almost wholly,
smooth off the surface of the body, and contract its length, thus giving
a greater convexity and angularity to the rings, and we have before us
the larva of the stately Luna moth that tops this royal family. Here are
certain criteria for placing these insects before our minds in the order
that nature has placed them. We have certain facts for determining which
of these three insects is highest and which lowest in the scale, when we
see the larva of the Luna moth throwing off successively the Io and
Cecropia forms to take on its own higher features. So that there is a
meaning in all this shifting of insect toggery.
This is but an example of the many ways in which both pleasure and
mental profit may be realized from the thoughtful study of caterpillar
life.
In collecting butterflies and moths for cabinet specimens, one needs a
gauze net a foot and a half deep, with the wire frame a foot in
diameter; a wide-mouthed bottle containing a parcel of cyanide of
potassium gummed on the side, in which to kill the moths, which should,
as soon as life is extinct, be pinned in a cork-lined collecting box
carried in the coat pocket. The captures should then be spread and dried
on a grooved setting board, and a cabinet formed of cork-lined boxes or
drawers; as a substitute for cork, frames with paper tightly stretched
over them may be used, or the pith of corn-stalks or palm wood.
Caterpillars should be preserved in spirits, or in glycerine with a
little alcohol added.
Some persons ingeniously empty the skins and inflate them over a flame
so that they may be pinned by the side of the adult.
Some of the most troublesome and noxious insects are found among the
moths. I need only mention the canker worm and American tent
caterpillar, and the various kinds of cut worms, as instances.
[Illustration: 43. Parasite of the American Silk Worm.]
We must not, however, forget the good done by insects. They undoubtedly
tend by their attacks to prevent an undue growth of vegetation. The
pruning done to a tree or herb by certain insects undoubtedly causes a
more healthy growth of the branches and leaves, and ultimately a greater
production fruit. Again, as pollen-bearers, insects are a most powerful
agency in nature. It is undoubtedly the fact that the presence, of bees
in orchards increases the fruit crop, and thus the thousands of moths
(though injurious as caterpillars), wild bees and other insects, that
seem to live without purpose, are really, though few realize it, among
the best friends and allies of man.
Moreover, insects are of great use as scavengers; such are the young or
maggots of the house fly, the mosquitoes, and numerous other forms, that
seem created only to vex us when in the winged state. Still a larger
proportion of insects are directly beneficial from their habit of
attacking injurious species, such as the ichneumons (Fig. 43, the
ichneumon of the American silk worm) and certain flies (Fig. 44,
Tachina); also many carnivorous species of wasps beetles and flies,
dragon flies and Aphis lions (Fig. 45, the lace-winged fly; adult, larva
and eggs).
[Illustration: 44. Tachina, parasite of Colorado Potato Beetle.]
[Illustration: 45. The Lace-winged Fly, Its Larva and Eggs.]
But few, however, suspect how enormous are the losses to crops in this
country entailed by the attacks of the injurious species. In Europe, the
subject of applied entomology has always attracted a great deal of
attention. Most sumptuous works, elegant quartos prepared by naturalists
known the world over, and published at government expense, together with
smaller treatises, have frequently appeared; while the subject is taught
in the numerous agricultural colleges and schools, especially of
Germany.
In the densely populated countries of Europe, the losses occasioned by
injurious insects are most severely felt, though from many causes, such
as the greater abundance of their insect parasites, and the far greater
care taken by the people to exterminate their insect enemies, they have
not proved so destructive as in our own land.
In this connection I may quote from one of Dr. Asa Fitch's reports on
the noxious insects of New York, where he says: "I find that in our
wheat-fields here, the midge formed 59 per cent. of all the insects on
this grain the past summer; whilst in France, the preceding summer, only
7 per cent. of the insects on wheat were of this species. In France the
parasitic destroyers amounted to 85 per cent.; while in this country our
parasites form only 10 per cent."
"A true knowledge of practical entomology may well be said to be in its
infancy in our own country, when, as is well-known to agriculturists,
the cultivation of wheat has almost been given up in New England, New
York, Pennsylvania, Ohio and Virginia, from the attacks of the wheat
midge, Hessian fly, joint worm, and chinch bug. According to Dr.
Shimer's estimate, says Mr. Riley, in his Second Annual Report on the
Injurious Insects of Missouri, which may be considered a reasonable
one, in the year 1864 three-fourths of the wheat, and one-half of the
corn crop were destroyed by the chinch bug throughout many extensive
districts, comprising almost the entire North-West. At the annual rate
of increase, according to the United States Census, in the State of
Illinois, the wheat crop ought to have been about thirty millions of
bushels, and the corn crop about one hundred and thirty-eight million
bushels. Putting the cash value of wheat at $1.25, and that of corn at
50 cents, the cash value of the corn and wheat destroyed by this
insignificant little bug, no bigger than a grain of rice, in one single
State and one single year, will therefore, according to the above
figures, foot up to the astounding total of _over seventy-three millions
of dollars_!"
The imported cabbage butterfly (Pieris rapæ), recently introduced from
Europe, is estimated by the Abbé Provatncher, a Canadian entomologist,
to destroy annually two hundred and forty thousand dollars' worth of
cabbages around Quebec. The Hessian fly, according to Dr. Fitch,
destroyed fifteen million dollars' worth of wheat in New York State in
one year (1854). The army worm of the North (Leucania unipuncta), which
was so abundant in 1861, from New England to Kansas, was reported to
have done damage that year in Eastern Massachusetts exceeding half a
million of dollars. The joint worm (Isosoma hordei) alone sometimes cuts
off whole fields of grain in Virginia and northward. The Colorado potato
beetle is steadily moving eastward, now ravaging the fields in Indiana
and Ohio, and only the forethought and ingenuity in devising means of
checking its attacks, resulting from a thorough study of its habits,
will deliver our wasted fields from its direful assaults.
These are the injuries done by the more abundant kinds of insects
injurious to crops. We should not forget that each fruit or shade tree,
garden shrub or vegetable, has a host of insects peculiar to it, and
which, year after year, renew their attacks. I could enumerate upwards
of fifty species of insects which prey upon cereals and grass, and as
many which infest our field crops. Some thirty well known species ravage
our garden vegetables. There are nearly fifty species which attack the
grape vine, and their number is rapidly increasing. About seventy-five
species make their annual onset upon the apple tree, and nearly an equal
number may be found upon the plum, pear, peach and cherry. Among our
shade trees, over fifty species infest the oak; twenty-five the elm;
seventy-five the walnut, and over one hundred species of insects prey
upon the pine.
Indeed, we may reasonably calculate the annual loss in our country
alone, from noxious animals and the lower forms of plants, such as rust,
smut and mildew, as (at a low estimate) not far from five hundred
million dollars annually. Of this amount, at least one-tenth, or fifty
million dollars, could probably be saved by human exertions.
To save a portion of this annual loss of food stuffs, fruits and lumber,
should be the first object of farmers and gardeners. When this saving is
made, farming will become a profitable and safe profession. But while a
few are well informed as to the losses sustained by injurious insects,
and use means to ward off their attacks, their efforts are constantly
foiled by the negligence of their neighbors. As illustrated so well by
the history of the incursions of the army worm and canker worm, it is
only by a combination between farmers and orchardists that these and
other pests can be kept under. The matter can be best reached by
legislation. We have fish and game laws; why should we not have an
insect law? Why should we not frame a law providing that farmers, and
all owning a garden or orchard, should cooperate in taking preventive
measures against injurious insects, such as early or late planting of
cereals, to avert the attacks of the wheat midge and Hessian fly; the
burning of stubble in the autumn and spring to destroy the joint worm;
the combined use of proper remedies against the canker worm, the
various cut worms, and other noxious caterpillars? A law carried out by
a proper State entomological constabulary, if it may be so designated,
would compel the idle and shiftless to clear their farms and gardens of
noxious animals.
[Illustration: 46. Pickle Worm and its Moth.]
Among some of the injurious insects reported on by Mr. Riley, the State
Entomologist of Missouri, is a new pest to the cucumber in the West, the
Pickle worm (Phacellura nitidalis, Fig. 46). This is a caterpillar which
bores into the cucumbers when large enough to pickle, and which is
occasionally found in pickles. Three or four worms sometimes occur in a
cucumber, and in the garden a single one will cause it to rot. One of
the most troublesome intruders in our graperies is the Vine dresser
(Choerocampa pampinatrix, Fig. 47, larva and pupa; Fig. 48, adult), a
single caterpillar of which will sometimes "strip a small vine of its
leaves in a few nights," and occasionally nips off bunches of half-grown
grapes.
[Illustration: 48. Vine Dresser Moth.
47. Vine Dresser and Chrysalis.]
Another caterpillar, which is sometimes so abundant as nearly to
defoliate the grape vine, is the eight spotted Alypia (Fig. 49; _a_,
larva; _b_, side view of a segment). This must not be confounded with
the bluish larva of the Wood Nymph, Eudryas grata (Fig. 50), which
differs from the Alypia caterpillar in being bluish, and in wanting the
white patches on the side of the body, and the more prominent hump on
the end of the body. Another moth (Psychomorpha epimenis, Fig. 51,
_a_, larva; _b_, side view of a segment; _c_, top view of the hump),
also feeds on the grape, eating the terminal buds. It is also bluish,
and wants the orange bands on the side of the body. Another moth of this
family is the American Procris (Acoloithus Americana, Fig. 52_a_, larva;
_b_, pupa; _c_, cocoon; _d_, _e_, imago); a dark blue moth, with a deep
orange collar, whose black and yellow caterpillar is gregarious (Fig.
53), living in companies of a dozen or more and eating the softer parts
of the leaves. It is quite common in the Western and Southern States.
The figure represents two separate broods of caterpillars feeding on
either side of the midrib of the leaf. But if the moths are, as a rule,
the enemies of our crops, there are the silk worms of the East and
Southern Europe and California, which afford the means of support to
multitudes of the poorer classes, and supply one of the most valuable
articles of clothing. Blot out the silk worm, and we should remove one
of the most important sources of national wealth, the annual revenue
from the silk trade of the world amounting to $254,500,000.
[Illustration: 49. Eight-spotted Alypia and Larva.]
[Illustration: 50. Eudryas grata.]
[Illustration: 51. Larva of Psychomorpha.]
[Illustration: 52. American Procris and Young.]
[Illustration: 53. Larvæ of American Procris.]
Silk culture is rapidly assuming importance in California, and though
the Chinese silk worm has not been successfully cultivated in the
Eastern States, yet the American silk worm, Teleas Polyphemus (see
frontispiece, male; Fig. 54, larva; 55, pupa; 56, cocoon), can, we are
assured by Mr. Trouvelot, be made a source of profit.
This is a splendid member of the group of which the gigantic Attacus
Atlas of China is a type. It is a large, fawn colored moth with a tawny
tinge; the caterpillar is pale green, and is of the size indicated in
the cut. Mr. Trouvelot says that of the several kinds of silk worms, the
larva of the present species alone deserves attention. The cocoons of
Platysamia Cecropia may be rendered of some commercial value, as the
silk can be carded, but the chief objection is the difficulty of raising
the larva.
"The Polyphemus worm spins a strong, dense, oval cocoon, which is closed
at each end, while the silk has a very strong and glossy fibre." Mr.
Trouvelot, from whose interesting account in the first volume of the
"American Naturalist" we quote, says that in 1865 "not less than a
million could be seen feeding in the open air upon bushes covered with a
net; five acres of woodland were swarming with caterpillar life." The
bushes were scrub oaks, the worms being protected by a net. After
meeting with such great success Mr. Trouvelot lost all his worms by
pebrine, the germs being imported in eggs received from Japan through M.
Guérin-Méneville of Paris. Enough, however, was done to prove that silk
raising can be carried on profitably, when due precautions are taken, as
far north as Boston. As this moth extends to the tropics, it can be
reared with greater facility southwards. The cocoon is strong and dense,
and closed at each end, so that the thread is continuous, while the silk
has a very strong and glossy fibre.
[Illustration: 54. American Silk Worm.]
Next in value to the American silk worm, is the Ailanthus silk worm
(Samia Cynthia) a species allied to our Callosamia Promethea. It
originated from China, where it is cultivated, and was introduced into
Italy in 1858, and thence spread into France, where it was introduced by
M. Guérin-Méneville. Its silk is said to be much stronger than the fibre
of cotton, and is a mean between fine wool and ordinary silk. The worm
is very hardy, and can be reared in the open air both in this country
and in Europe. The main drawback to its culture is the difficulty in
unreeling the tough cocoon, and the shortness of the thread, the cocoon
being open at one end.
The Yama-maï moth (Antheræa Yama-maï) was introduced into France from
Japan in 1861. It is closely allied to the Polyphemus moth, and its
caterpillar also feeds on the oak. Its silk is said to be quite
brilliant, but a little coarser and not so strong as that of the Bombyx
mori. The Perny silk worm is extensively cultivated by the Chinese in
Manchouria, where it feeds on the oak. Its silk is coarser than that of
the common silk worm, but is yet fine, strong and glossy. Bengal has
furnished the Tussah moth, which lives in India on the oak and a variety
of other trees. It is largely raised in French and English India,
according to Nogués, and is used in the manufacture of stuffs called
corahs.
[Illustration: 55. Chrysalis of American Silk Worm.]
[Illustration: 56. Cocoon of American Silk Worm.]
The last kind of importance is the Arrhindy silk worm, from India. It
has been naturalized in France and Algeria by M. Guérin-Méneville, who
has done so much in the application of entomology to practical life. It
is closely allied to the Cynthia or Ailanthus worm, with the same kind
of silk and a similar cocoon, and feeds on the castor oil plant.
The diseases of silk worms naturally receive much attention. Like those
afflicting mankind, they arise from bad air, resulting from too close
confinement, bad food, and other adverse causes. The most fatal and
wide-spread disease, and one which since 1854 has threatened the
extermination of silk worms in Europe, is the _pebrine_. It is due to
the presence of minute vegetable corpuscles, which attack both the worms
and the eggs. It was this disease which swept off thousands of Mr.
Trouvelot's Polyphemus worms, and put a sudden termination to his
important experiments, the germs having been implanted in eggs of the
Yama-maï moth imported from Japan by M. Guérin-Méneville, and which were
probably infected as they passed through Paris. Though the disaster
happened several years since, he tells us that it will be useless for
him to attempt the raising of silk worms in the town where his
establishment is situated, as the germs of the disease are most
difficult to eradicate.
So direful in France were the ravages of this disease that two of the
most advanced naturalists in France, Quatrefages and Pasteur, were
commissioned by the French government to investigate the disease.
Pasteur found that the infected eggs differed in appearance from the
sound ones, and could thus be sorted out by aid of the microscope and
destroyed. Thus these investigations, carried on year after year, and
seeming to the ignorant to tend to no practical end, resulted in saving
to France her silk culture. During the past year (1871) so successful
has his method proved that a French scientific journal expresses the
hope of the complete reestablishment and prosperity of this great
industry. A single person who obtained in 1871 in his nurseries 30,000
ounces of eggs, hopes the next year to obtain 100,000 ounces, from which
he expects to realize about one million dollars.
[Illustration: The Potato Caterpillar.]
CHAPTER V.
THE CLOTHES MOTH.
For over a fortnight we once enjoyed the company of the caterpillar of a
common clothes moth. It is a little pale, delicate worm (Fig. 57,
magnified), about the size of a darning needle, and rather less than
half an inch in length, with a pale horn-colored head, the ring next the
head being of the same color. It has sixteen feet, the first six of them
well developed and constantly in use to draw the slender body in and out
of its case. Its head is armed with a formidable pair of jaws, with
which, like a scythe, it mows its way through thick and thin.
But the case is the most remarkable feature in the history of this
caterpillar. Hardly has the helpless, tiny worm broken out of the egg,
previously laid in some old garment of fur or wool, or perhaps in the
haircloth of a sofa, when it begins to make a shelter by cutting the
woolly fibres or soft hairs into bits, which it places at each end in
successive layers, and, joining them together by silken threads,
constructs a cylindrical tube (Fig. 58) of thick, warm felt, lined
within with the finest silk the tiny worm can spin. The case is not
perfectly cylindrical, being flattened slightly in the middle, and
contracted a little just before each end, both of which are always kept
open. The case before us is of a stone-gray color, with a black stripe
along the middle, and with rings of the same color round each opening.
Had the caterpillar fed on blue or yellow cloth, the case would, of
course, have been of those colors. Other cases, made by larvæ which had
been eating loose cotton, were quite irregular in form, and covered
loosely with bits of cotton thread, which the little tailor had not
trimmed off.
Days go by. A vigorous course of dieting on its feast of wool has given
stature to our hero. His case has grown uncomfortably small. Shall he
leave it and make another? No housewife is more prudent and saving. Out
come those scissor-jaws, and, lo! a fearful rent along each side of one
end of the case. Two wedge-shaped patches mend the breach; the
caterpillar retires for a moment and reappears at the other end; the
scissors are once more pulled out; two rents appear, to be filled up by
two more patches or gores, and our caterpillar once again breathes more
freely, laughs and grows fat upon horse hair and lambs' wool. In this
way he enlarges his case till he stops growing.
[Illustration: 59. 58. 57.
Early Stages of the Clothes Moth.]
Our caterpillar seeming to be full-grown, and apparently out of
employment, we cut the end of his case half off. Two or three days
after, he had mended it from the inside, drawing the two edges together
by silken threads, and, though he had not touched the outside, yet so
neatly were the two parts joined together that we had to search for some
time, with a lens, to find the scar.
To keep our friend busy during the cold, cheerless weather, for it was
mid-winter, we next cut a third of the case entirely off. Nothing
daunted, the little fellow bustled about, drew in a mass of the woolly
fibres, filling up the whole mouth of his den, and began to build on
afresh, and from the inside, so that the new-made portion was smaller
than the rest of the case. The creature worked very slowly, and the
addition was left in a rough, unfinished state.
We could easily spare these voracious little worms hairs enough to serve
as food, and to afford material for the construction of their paltry
cases; but that restless spirit that ever urges on all beings endowed
with life and the power of motion, never forsakes the young clothes moth
for a moment. He will not be forced to drag his heavy case over rough
hairs and furzy wool, hence with his keen jaws he cuts his way through.
Thus, the more he travels, the more mischief he does.
After taking his fill of this sort of life he changes to a chrysalid
(Fig. 59), and soon appears as one of those delicate, tiny, demure
moths that fly in such numbers from early in the spring until the
autumn.
Very many do not recognize these moths in their perfect stage, so small
are they, and vent their wrath on those great millers that fly around
lamps in warm summer evenings. It need scarcely be said that these large
millers are utterly guiltless of any attempts upon our wardrobes; they
make their attacks in a more open form on our gardens and orchards.
We will give a more careful description of the clothes moth, which was
found in its different stages June 12th in a mass of loose cotton. The
larva is white, with a tolerably plump body, which tapers slightly
towards the tail, while the head is much of the color of gum-copal. The
rings of the body are thickened above, especially on the thoracic ones,
by two transverse thickened folds. It is one-fifth of an inch long.
The body of the chrysalis, or pupa, is considerably curved, with the
head smooth and rounded. The long antennæ, together with the hind legs,
which are folded along the breast, reach to the tip of the hind body, on
the upper surface of each ring of which is a short transverse row of
minute spines, which aid the chrysalis in moving towards the mouth of
its case, just before the moth appears. At first the chrysalis is
whitish, but just before the exclusion of the moth becomes the color of
varnish.
When about to cast its pupa skin, the skin splits open on the back, and
the perfect insect glides out. The act is so quickly over with, that the
observer has to look sharp to observe the different steps in the
operation.
[Illustration: 60. Clothes Moth.]
Our common clothes moth (Tinea flavifrontella, Fig. 60) is of a uniform
light-buff color, with a silky iridescent lustre, the hind wings and
abdomen being a little paler. The head is thickly tufted with hairs and
is a little tawny, and the upper side of the densely hirsute feelers
(palpi) is dusky. The wings are long and narrow, with the most beautiful
and delicate long silken fringe, which increases in length towards the
base of the wing.
They begin to fly in May, and last all through the season, fluttering
with a noiseless, stealthy flight in our apartments, and laying their
eggs in our woollens.
Successive broods of the clothes moth appear through the summer. In the
autumn they cease eating, retire within their cases, and early in spring
assume the chrysalis state.
There are several allied species which have much the same habits, except
that they do not all construct cases, but eat carpets, clothing,
articles of food, grain, etc., and objects of natural history.
Careful housewives are not much afflicted with these pests. The slovenly
and thriftless are overrun with them. Early in June woollens and furs
should be carefully dusted, shaken and beaten. Dr. T. W. Harris states
that "powdered black pepper, strewed under the edge of carpets, is said
to repel moths. Sheets of paper sprinkled with spirits of turpentine,
camphor in coarse powder, leaves of tobacco, or shavings of Russia
leather, should be placed among the clothes when they are laid aside for
the summer; and furs and other small articles can be kept by being sewed
in bags with bits of camphor wood, red cedar, or of Spanish cedar; while
the cloth lining of carriages can be secured forever from the attacks of
moths by being washed or sponged on both sides with a solution of the
corrosive sublimate of mercury in alcohol, made just strong enough not
to leave a white stain on a black feather." The moths can be most
readily killed by pouring benzine among them, though its use must be
much restricted from the disagreeable odor which remains. The recent
experiments made with carbolic acid, however, convince us that this will
soon take the place of other substances as a preventive and destroyer of
noxious insects.
[Illustration: The Juniper Sickle-wing.]
CHAPTER VI.
THE MOSQUITO AND ITS FRIENDS.
The subject of flies becomes of vast moment to a Pharaoh, whose ears are
dinned with the buzz of myriad winged plagues, mingled with angry cries
from malcontent and fly-pestered subjects; or to the summer traveller in
northern lands, where they oppose a stronger barrier to his explorations
than the loftiest mountains or the broadest streams; or to the African
pioneer, whose cattle, his main dependence, are stung to death by the
Tsetze fly; or the fariner whose eyes on the evening of a warm spring
day, after a placid contemplation of his growing acres of wheat blades,
suddenly detects in dismay clouds of the Wheat midge and Hessian fly
hovering over their swaying tops. The subject, indeed, has in such cases
a national importance, and a few words regarding the main points in the
habits of flies--how they grow, how they do not grow (after assuming the
winged state), and how they bite; for who has not endured the smart and
sting of these dipterous Shylocks, that almost torment us out of our
existence while taking their drop of our heart's blood--may be welcome to
our readers.
[Illustration: 61. Head of the Mosquito.]
The Mosquito will be our first choice. As she leaps off from her light
bark, the cast chrysalis skin of her early life beneath the waters, and
sails away in the sunlight, her velvety wings fringed with silken hairs,
and her neatly bodiced trim figure (though her nose is rather salient,
considering that it is half as long as her entire body), present a
beauty and grace of form and movement quite unsurpassed by her dipterous
allies. She draws near and softly alights upon the hand of the charmed
beholder, subdues her trumpeting notes, folds her wings noiselessly upon
her back, daintily sets down one foot after the other, and with an
eagerness chastened by the most refined delicacy for the feelings of her
victim, and with the air of Velpeau redivivus, drives through crushed
and bleeding capillaries, shrinking nerves and injured tissues, a
many-bladed lancet of marvellous fineness, of wonderful complexity and
fitness. While engorging herself with our blood, we will examine under
the microscope the mosquito's mouth. The head (Fig. 61) is rounded, with
the two eyes occupying a large part of the surface, and nearly meeting
on the top of the head. Out of the forehead, so to speak, grow the long,
delicate, hairy antennm (_a_), and just below arises the long beak which
consists of the bristle-like maxillæ (_mx_, with their palpi, _mp_) and
mandibles (_m_), and the single hair-like labrum, these five
bristle-like organs being laid in the hollowed labium (_l_). Thus massed
into a single awl-like beak, the mosquito, without any apparent effort,
thrusts them all except the labium into the flesh. Her hind body may be
seen tilling with the red blood, until it cries quits, and the insect
withdraws its sting and flies sluggishly away. In a moment the wounded
parts itch slightly, though a very robust person may not notice the
irritation, or a more delicate individual if asleep; though if weakened
by disease, or if stung in a highly vascular and sensitive part, such as
the eyelid, the bite becomes really a serious matter. Multiply the
mosquito a thousand fold, and one flees their attacks and avoids their
haunts as he would a nest of hornets. Early in spring the larva (Fig.
62, A) of the mosquito may be found in pools and ditches. It remains at
the bottom feeding upon decaying matter (thus acting as a scavenger, and
in this state doing great benefit in clearing swamps of miasms), until
it rises to the surface for air, which it inhales through a single
respiratory tube (_c_) situated near the tail. When about to transform
into the pupa state, it contracts and enlarges anteriorly near the
middle, the larval skin is thrown off, and the insect appears in quite a
different form (Fig. 62, a). The head and thorax are massed together,
the rudiments of the mouth parts and of the wings and legs being folded
upon the breast, while there are two breathing tubes (_d_) situated upon
the back instead of the tail, which ends in two broad paddles (_a_); so
that it comes to the surface, head foremost instead of tail first, a
position according better with its increased age and experience in pond
life. In a few days the pupa skin is cast; the insect, availing itself
of its old habiliments as a raft upon which to float while its body is
drying, grows lighter, and its wings expand for its marriage flight. The
males are beautiful, both physically and morally, as they do not bite;
their manners are more retiring than those of their stronger minded
partners, as they rarely enter our dwellings, and live unnoticed in the
woods. They may be easily distinguished from the females by their long
maxillary palpi, and their thick, bushy, feathered antennæ. The female
lays her elongated, oval eggs in a boat-shaped mass, which floats on the
water. A mosquito lives three or four weeks in the water before changing
to the adult or winged stage. How many days they live in the latter
state we do not know.
[Illustration: 62. Larva and Pupa of the Mosquito.]
Our readers will understand, then, that all flies, like our mosquito for
example, grow while in the larva and pupa state, _and after they acquire
wings do not grow_, so that the small midges are not young mosquitoes,
but the adult winged forms of an entirely different species and genus of
fly; and the myriads of small flies, commonly supposed to be the young
of larger flies, are adult forms belonging to different species of
different genera, and perhaps of different families of the suborder of
Diptera. The typical species of the genus Culex, to which the mosquito
belongs, is Culex pipiens, described by Linnæus, and there are already
over thirty North American species of this genus described in various
works. Few insects live in the sea, but along the coast of New England
a small, slender white larva (Fig. 63a, magnified, and head greatly
enlarged; Fig. 64, pupa and fore foot of larva, showing the hooks),
whose body is no thicker than a knitting needle, lives between tides,
and has even been dredged at a depth of over a hundred feet, which
transforms into a yellow mosquito-like fly (Fig. 65, with head of the
female, magnified) which swarms in summer in immense numbers. I have
called it provisionally Chironomus oceanicus, or Ocean gnat. The larvæ
of other species have been found by Mr. S. I. Smith living at great
depths in our Northern lakes. These kinds of gnats are usually seen
early in spring hovering in swarms in mid air.
[Illustration: 65. Ocean Gnat.]
[Illustration: 63. Larva of Ocean Gnat.]
[Illustration: 64. Pupa of Ocean Gnat.]
The strange fact has been discovered by Grimm, a Russian naturalist,
that the pupa of a feathered gnat is capable of laying eggs which
produce young during the summer time. Previous to this it had been
discovered that a larva of a gnat (Fig. 66 _a_, eggs from which the
young are produced) which lives under the bark of trees in Europe, also
produced young born alive.
The Hessian fly (Fig. 67, _a_, larva; _b_ pupa; _c_, stalk of wheat
injured by larvæ) and Wheat midge, which are allied to the mosquito, are
briefly referred to in the calendar, so that we pass over these to
consider another pest of our forests and prairies.
[Illustration: 66. Viviparous gall larva.]
[Illustration: 67. Hessian Fly and its Young.]
The Black fly is even a more formidable pest than the mosquito. In the
northern, subarctic regions, it opposes a barrier against travel. The
Labrador fisherman spends his summer on the sea shore, scarcely daring
to penetrate the interior on account of the swarms of these flies.
During a summer residence on this coast, we sailed up the Esquimaux
river for six or eight miles, spending a few hours at a house situated
on the bank. The day was warm and but little wind blowing, and the
swarms of black flies were absolutely terrific. In vain we frantically
waved our net among them, allured by some rare moth; after making a few
desperate charges in the face of the thronging pests, we had to retire
to the house, where the windows actually swarmed with them; but here
they would fly in our faces, crawl under one's clothes, where they even
remain and bite in the night. The children in the house were sickly and
worn by their unceasing torments; and the shaggy Newfoundland dogs whose
thick coats would seem to be proof against their bites ran from their
shelter beneath the bench and dashed into the river, their only retreat.
In cloudy weather, unlike the mosquito, the black fly disappears, only
flying when the sun shines. The bite of the black fly is often severe,
the creature leaving a large clot of blood to mark the scene of its
surgical triumphs. Prof. E. T. Cox, State Geologist of Indiana, has sent
us specimens of a much larger fly, which Baron Osten Sacken refers to
this genus, which is called on the prairies, where it is said to bite
horses to death, the Buffalo Gnat. Westwood states that an allied fly
(Rhagio Columbaschensis) is one of the greatest scourges of man and
beast in Hungary, where it has been known to kill cattle.
[Illustration: 68. Black fly.]
[Illustration: 69. Black Fly Larva.]
The Simulium molestum (Fig. 68, enlarged), as the black fly is called,
lives during the larva state in the water. The larva of a Labrador
species (Fig. 69, enlarged) which we found, is about a quarter of an
inch long, and of the appearance here indicated. The pupa is also
aquatic, having long respiratory filaments attached to each side of the
front of the thorax. According to Westwood, "the posterior part of its
body is enclosed in a semioval membranous cocoon, which is at first
formed by the larva, the anterior part of which is eaten away before
changing to a pupa, so as to be open in front. The imago is produced
beneath the surface of the water, its fine silky covering serving to
repel the action of the water."
[Illustration: 70. Mycetobia.]
Multitudes of a long, slender, white worm may often be found living in
the dirt, and sour sap running from wounds in the elm tree. Two summers
ago we discovered some of these larvæ, and on rearing them found that
they were a species of Mycetobia (Fig. 70; _a_, larva; _b_, pupa). The
larva is remarkable for having the abdominal segments divided into two
portions, the hinder much smaller than the anterior division. Its whole
length is a little over a third of an inch. The pupæ were found sticking
out in considerable numbers from the tree, being anchored by the little
spines at the tail. The head is square, ending in two horns, and the
body is straight and covered with spines, especially towards the end of
the tail. They were a fifth of an inch in length. The last of June the
flies appeared, somewhat resembling gnats, and about a line long. The
worms continued to infest the tree for six weeks, the flies remaining
either upon or near it.
[Illustration: 71. Mouth Parts of Tabanus.]
We now come to that terror of our equine friends, the Horse fly, Gad, or
Breeze fly. In its larval state, some species live in water, and in damp
places under stones and pieces of wood, and others in the earth away
from water, where they feed on animal, and, probably, on decaying
matter. Mr. B. D. Walsh found an aquatic larva of this genus, which,
within a short time, devoured eleven water snails. Thus at this stage of
existence, this fly, often so destructive, even at times killing our
horses, is beneficial. During the hotter parts of summer, and when the
sun is shining brightly, thousands of these Horse flies appear on our
marshes and inland prairies. There are many different kinds, over one
hundred species of the genus Tabanus alone, living in North America. Our
most common species is the "Green head," or Tabanus lineola. When about
to bite, it settles quietly down upon the hand, face or foot, it matters
not which, and thrusts its formidable lancet-like jaws deep into the
flesh. Its bite is very painful, as we can testify from personal
experience. We were told during the last summer that a horse, which
stood fastened to a tree in a field near the marshes at Rowley, Mass.,
was bitten to death by these Green heads; and it is known that horses
and cattle are occasionally killed by their repeated harassing bites. In
cloudy weather they do not fly, and they perish on the cool frosty
nights of September. The Timb, or Tsetze fly, is a species of this group
of flies, and while it does not attack man, plagues to death, and is
said to poison by its bite, the cattle in certain districts of the
interior of Africa, thus almost barring out explorers. On comparing the
mouth-parts of the Horse fly (Fig. 71, mouth of T. lineola), we have all
the parts seen in the mosquito, but greatly modified. Like the mosquito,
the females alone bite, the male Horse fly being harmless, and
frequenting flowers, living upon their sweets. The labrum (_lb_),
mandibles (_m_) and maxillæ (_mx_), are short, stiff and lancet-like,
and the maxillary palpi (_mp_; _a_, the five terminal joints of the
antennæ) are large, stout, and two-jointed. While the jaws (both maxillæ
and mandibles) are thrust into the flesh, the tongue (_l_) spreads
around the tube thus formed by the lancets, and pumps up the blood
flowing from the wound, by aid of the sucking stomach, or crop, being a
sac appended to the throat. Other Gad flies, but much smaller, though as
annoying to us in woods and fields, are the species of Golden eyed
flies, Chrysops, which fly and buzz interminably about our ears, often
taking a sudden nip. They plague cattle, settling upon them and drawing
their blood at their leisure.
[Illustration: 72. Carpet Fly.]
[Illustration: 73. Carpet Worm.]
We turn to a comparatively unknown insect, which has occasionally
excited some distrust in the minds of housekeepers. It is the carpet
fly, Scenopinus pallipes (Fig. 72), which, in the larva state, is found
under carpets, on which it is said to feed. The worm (Fig. 73) has a
long, white, cylindrical body, divided into twelve segments, exclusive
of the head, while the first eight abdominal segments are divided by a
transverse suture, so that there appear to be seventeen abdominal
segments, the sutures appearing too distinct in the cut. Mr. F. G.
Sanborn has reared the fly, here figured, from the worm. The larva also
lives in rotten wood; it is too scarce ever to prove very destructive in
houses. Either this or a similar fly was once found, we are told by a
scientific friend, in great numbers in a "rat" used in dressing a young
lady's hair; the worms were living upon the hair stuffing.
One of the most puzzling objects to the collector of shells or insects,
is the almost spherical larva of Microdon globosus (Fig. 74). It is
flattened and smooth beneath and seems to adhere to the under side of
stones, where it might be mistaken for a snail.
The Syrphus fly, or Aphis eater, deserves more than the passing notice
which we bestow upon it. The maggot (Fig. 75, in the act of devouring an
Aphis) is to be sought for established in a group of plant lice (Aphis),
which it seizes by means of the long extensible front part of the body.
The adult fly (Fig. 76) is gayly spotted and banded with yellow,
resembling closely a wasp. It frequents flowers.
[Illustration: 74. Microdon.]
[Illustration: 75. Syrphus Larva.] 76. Syrphus Fly.]
[Illustration: 77. Larva of Rat-tailed Fly. 78. Rat-tailed Fly and its
Pupa.]
The singular rat-tailed pupa-case of Eristalis (Fig. 77) lives in water,
and when in want of air, protrudes its long respiratory tube out into
the air. We present the figure of an allied fly, Merodon Bardus (Fig.
78; _a_, puparium, natural size). We will not describe at length the
fly, as the admirable drawings of Mr. Emerton cannot fail to render it
easily recognizable. The larva is much like the puparium or pupa case,
here figured, which closely resembles that of Eristalis, in possessing
along respiratory filament, showing that the maggot undoubtedly lives in
the water, and when desirous of breathing, protrudes the tube out of the
water, thus drawing in air enough to fill its internal respiratory tubes
(tracheæ). The Merodon Narcissa probably lives in the soil, or in rotten
wood, as the pupa-case has no respiratory tube, having instead a very
short, sessile, truncated tube, scarcely as long as it is thick. The
case itself is cylindrical, and rounded alike at each end.
[Illustration: 79. Human Bot Worm.]
We now come to the Bot flies, which are among the most extraordinary, in
their habits, of all insects. The history of the Bot flies is in brief
thus. The adult two-winged fly lays its eggs on the exterior of the
animal to be infested. They are conveyed into the interior of the host,
where they hatch, and the worm or maggot lives by sucking in the
purulent matter, caused by the irritation set up by its presence in its
host; or else the worm itself, after hatching, bores under the skin.
When fully grown, it quits the body and finishes its transformations to
the fly-state under ground. Many quadrupeds, from mice, squirrels, and
rabbits, up to the ox, horse, and even the rhinoceros, suffer from their
attacks, while man himself is not exempt. The body of the adult fly is
stout and hairy, and it is easily recognized by having the opening of
the mouth very small, the mouth-parts being very rudimentary. The larvæ
are, in general, thick, fleshy, footless grubs, consisting of eleven
segments, exclusive of the head, which are covered with rows of spines
and tubercles, by which they move about within the body, thus irritating
the animals in which they take up their abode. The breathing pores
(stigmata) open in a scaly plate at the posterior end of the body. The
mouth-parts (mandibles, etc.) of the subcutaneous larvæ consist of
fleshy tubercles, while in those species which live in the stomachs and
frontal sinuses of their host, they are armed with horny hooks.
[Illustration: 80. Horse Bot Fly.]
The larvæ attain their full size after moulting twice. Just before
assuming the pupa state, the maggot leaves its peculiar dwelling place,
descends into the ground and there becomes a pupa, though retaining its
larval skin, which serves as a protection to it, whence it is called a
"puparium."
Several well-authenticated instances are on record of a species of bot
fly inhabiting the body of man, in Central and South America, producing
painful tumors under the skin of the arm, legs and abdomen. It is still
under dispute whether this human bot fly is a true or accidental
parasite, the more probable opinion being that its proper host is the
monkey or dog. In Cayenne, this revolting grub is called the Ver macaque
(Fig. 79); in Para, Ura; in Costa Rica, Torcel; and in New Granada,
Gusano peludo, or Nuche. The Dermatobia noxialis, supposed to be the Ver
moyocuil of the inhabitants of Mexico and New Granada, lives beneath the
skin of the dog.
[Illustration: 81. Bot Fly of Ox, and Larva.]
[Illustration: 82. Sheep Bot.]
[Illustration: 83. Skin Bot Fly.]
The Bot fly of the horse, (Gastrophilus equi, Fig. 80 and larva), is
pale yellowish, spotted with red, with short, grayish, yellow hairs, and
the wings are banded with reddish. She lays her eggs upon the knees of
the horse. They are conveyed into the stomach, where the larva lives
from May until October, and when full grown are found hanging by their
mouth hooks on the edge of the rectum of the horse, whence they are
carried out in the excrement. The pupa state lasts for thirty or forty
days, and the perfect fly appears the next season, from June until
October.
The Bot fly of the ox (Hypoderma bovis, Fig. 81, and larva), is black
and densely hairy, and the thorax is banded with yellow and white. The
larva is found during the month of May, and also in summer, living in
tumors on the backs of cattle. When fully grown, which is generally in
July, they make their way out and fall to the ground, and live in the
pupa-case from twenty-six to thirty days, the fly appearing from May
until September. It is found all over the world. The Oestrus ovis, or
sheep Bot fly (Fig. 82, larva), is of a dirty ash color. The abdomen is
marbled with yellowish and white flecks, and is hairy at the end. This
species of Bot fly is larviparous, i.e., the eggs are hatched within the
body of the mother, the larvæ being produced alive. M. F. Brauer, of
Vienna, the author of the most thorough work we have on these flies,
tells me that he knows of but one other Bot fly (a species of
Cephanomyia) which produces living larvæ instead of eggs. The eggs of
certain other species of Bot flies do not hatch until three or four days
after they are laid. The larvæ of the sheep Bot fly live, during April,
May and June, in the frontal sinus of the sheep, and also in the nasal
cavity, whence they fall to the ground when fully grown. In twenty-four
hours they change to pupæ, and the flies appear during the summer.
We also figure the Cuterebra buccata (Fig. 83; _a_, side view,) which
resembles in the larval state the ox Bot fly. Its habits are not known,
though the young of other species infest the opossum, squirrel, hare,
etc., living in subcutaneous tumors.
[Illustration: The banded Lithacodes.]
CHAPTER VII.
THE HOUSE FLY AND ITS ALLIES.
[Illustration: 84. Mouth-parts of the House fly.]
The common House fly, Musca domestica, scarcely needs an introduction to
any one of our readers, and its countenance is so well known that we
need not present a portrait here. But a study of the proboscis of the
fly reveals a wonderful adaptability of the mouth-parts of this insect
to their uses. We have already noticed the most perfect condition of
these parts as seen in the horse fly. In the proboscis of the house fly
the hard parts are obsolete, and instead we have a fleshy tongue like
organ (Fig. 84), bent up beneath the head when at rest. The maxillæ are
minute, their palpi (_mp_) being single-jointed, and the mandibles (_m_)
are comparatively useless, being very short and small, compared with the
lancet-like jaws of the mosquito or horse fly. But the structure of the
tongue itself (labium, l) is most curious. When the fly settles upon a
lump of sugar or other sweet object, it unbends its tongue, extends it,
and the broad knob-like end divides into two broad, flat, muscular
leaves (_l_), which thus present a sucker-like surface, with which the
fly laps up liquid sweets. These two leaves are supported upon a
framework of tracheal tubes. In the cut given above, Mr. Emerton has
faithfully represented these modified trachæ, which end in hairs
projecting externally. Thus the inside of this broad fleshy expansion
is rough like a rasp, and as Newport states, "is easily employed by the
insect in scraping or tearing delicate surfaces. It is by means of this
curious structure that the busy house fly occasions much mischief to the
covers of our books, by scraping off the albuminous polish, and leaving
tracings of its depredations in the soiled and spotted appearance which
it occasions on them. It is by means of these also that it teases us in
the heat of summer, when it alights on the hand or face to sip the
perspiration as it exudes from, and is condensed upon, the skin."
[Illustration: 85. Larva; _a_, Pupa-case of House fly.]
[Illustration: 86. Larva of Flesh fly.]
Every one notices that house flies are most abundant around barns in
August and September, and it is in the ordure of stables that the early
stages of this insect are passed. No one has traced the transformations
of this fly in our country, but we copy from Bouché's work on the
transformations of insects, the rather rude figures of the larva (Fig.
85), and pupa-case (_a_) of the Musca domestica of Europe, which is
supposed to be our species. Bouché states that the larva is cylindrical,
rounded posteriorly, smooth and shining, fleshy, and yellowish white,
and four lines long. The pupa-case, or puparium, is dark reddish-brown,
and three lines in length. It remains in the pupa state from eight to
fourteen days. In Europe it is preyed upon by minute ichneumon flies
(Chalcids). The flesh fly, Musca Cæsar, or the Blue-bottle fly, feeds
upon decaying animal matter. Its larva (Fig. 86) is long, cylindrical,
the head being pointed, and the body conical, the posterior end being
squarely docked. The larva of a Sargus-like form which feeds on offal,
transforms into a flattened pupa-case (Fig. 87), provided with long,
scattered hairs. The House fly disappears in autumn, at the approach of
cold weather, though a few individuals pass through the winter,
hibernating in houses, and when the rooms are heated may often be seen
flying on the windows. Other species fly early in March, on warm days,
having hibernated under leaves, and the bark of trees, moss, etc. An
allied species, the M. vomitoria, is the Meat fly. Closely allied are
the parasitic species of Tachina, which live within the bodies of
caterpillars and other insects, and are among the most beneficial of
insects, as they prey on thousands of injurious caterpillars. Another
fly of this Muscid group, the Idia Bigoti, according to Coquerel and
Mondiere, produces in the natives of Senegal, hard, red, fluctuating
tumors, in which the larva resides.
[Illustration: 87. Larva of a Sargus-like fly.]
Many of the smaller Muscids mine leaves, running galleries within the
leaf, or burrowing in seeds or under the bark of plants. We have often
noticed blister-like swellings on the bark of the willow, which are
occasioned by a cylindrical, short, fleshy larva (Fig. 88_a_, much
enlarged), about a line in length, which changes to a pupa within the
old larval skin, assuming the form here represented (Fig. 88_b_), and
about the last of June changes to a small black fly (Fig. 88), which
Baron Osten Sacken refers doubtfully to the genus Lonchæa.
[Illustration: 86. Willow Blister fly.]
The Apple midge frequently does great mischief to apples after they are
gathered. Mr. F. G. Sanborn states that nine-tenths of the apple crop in
Wrentham, Mass., were destroyed by a fly supposed to be the Molobrus
mali, or Apple midge, described by Dr. Fitch. "The eggs were supposed to
have been laid in fresh apples, in the holes made by the Coddling moth
(Carpocapsa pomonella), whence the larvæ penetrated into all parts of
the apple, working small cylindrical burrows about one-sixteenth of an
inch in diameter." Mr. W. C. Fish has also sent me, from Sandwich,
Mass., specimens of another kind of apple worm, which he writes has been
very common in Barnstable county. "It attacks mostly the earlier
varieties, seeming to have a particular fondness for the old fashioned
Summer, or High-top Sweet. The larvæ (Fig. 89 _a_) enter the fruit
usually where it has been bored by the Apple worm (Carpocapsa), not
uncommonly through the crescent-like puncture of the curculio, and
sometimes through the calyx, when it has not been troubled by other
insects. Many of them arrive at maturity in August, and the fly soon
appears, successive generations of the maggots following until cold
weather. I have frequently found the pupæ in the bottom of barrels in a
cellar in the winter, and the flies appear in the spring. In the early
apples, the larvæ work about in every direction. If there be several in
an apple, they make it unfit for use. Apples that appear perfectly sound
when taken from the tree, will sometimes, if kept, be all alive with
them in a few weeks." Baron Osten Sacken informs me that it is a
Drosophila, "the species of which live in putrescent vegetable matter,
especially fruits."
[Illustration: 89. Apple Worm and its Larva.]
[Illustration: 90. Parent of the Cheese Maggot.]
[Illustration: 91. Pupa case of Wine-fly.]
An allied fly is the parent of the cheese maggot. The fly itself
(Piophila casei, Fig. 90) is black, with metallic green reflections, and
the legs are dark and paler at the knee-joints, the middle and hind pair
of tarsi being dark honey yellow. The Wine fly is also a Piophila, and
lives the life of a perpetual toper in old wine casks, and partially
emptied beer, cider and wine bottles, where, with its pupa-case (Fig.
91), it may be found floating dead in its favorite beverage.
[Illustration: 92. Bird Tick.]
We now come to the more degraded forms of flies which live parasitically
on various animals. We figure, from a specimen in the Museum of the
Peabody Academy of Science, the Bird tick (Ornithomyia, Fig. 92), which
lives upon the Great Horned Owl. Its body is much flattened, adapted for
its life under the feathers, where it gorges itself with the blood of
its host.
[Illustration: 93. The Horse Tick.]
Here belongs also the Horse tick (Hippobosca equina, Fig. 93). It is
about the size of the house fly, being black, with yellow spots on the
thorax. Verrill[4] says that "it attacks by preference those parts where
the hair is thinnest and the skin softest, especially under the belly
and between the hind legs. Its bite causes severe pain, and will
irritate the gentlest horses, often rendering them almost unmanageable,
and causing them to kick dangerously. When found, they cling so firmly
as to be removed with some difficulty, and they are so tough as not to
be readily crushed. If one escapes when captured, it will instantly
return to the horse, or, perchance, to the head of its captor, where it
is an undesirable guest. Another species sometimes infests the ox."
[Illustration: 94. Sheep Tick.]
[Illustration: 95. Bat Tick.]
In the wingless Sheep tick (Melophagus ovinus, Fig. 94, with the
pupa-case on the left), the body is wingless and very hairy, and the
proboscis is very long. The young are developed within the body of the
parent, until they attain the pupa state, when she deposits the pupa
case, which is nearly half as large as her abdomen. Other genera are
parasitic on bats; among them are the singular spider-like Bat ticks
(Nycteribia, Fig. 95), which have small bodies and enormous legs, and
are either blind, or provided with four simple eyes. They are of small
size, being only a line or two in length. Such degraded forms of Diptera
have a remarkable resemblance to the spiders, mites, ticks, etc. The
reader should compare the Nycteribia with the young six-footed moose
tick figured farther on. Another spider-like fly is the Chionea valga
(Fig. 96; and 97, larva of the European species), which is a degraded
Tipula, The latter genus standing near the head of the Diptera. The
Chionea, according to Harris, lives in its early, stages in the ground
like many other gnats, and is found early in the spring, sometimes
crawling over the snow. We have also figured and mentioned previously
(page 41) the Bee louse, Braula, another wingless spider-like fly.
[Illustration: 96. Spider fly.]
[Illustration: 97. Larva of Spider fly.]
The Flea is also a wingless fly, and is probably, as has been suggested
by an eminent entomologist, as Baron Osten Sacken informs us, a degraded
genus of the family to which Mycetobia belongs. Its transformations are
very unlike those of the fly ticks, and agree closely with the early
stages of Mycetophila, one of the Tipulid family. In its adult condition
the flea combines the characters of the Diptera, with certain features
of the grasshoppers and cockroaches, and the bugs. The body of the flea
(Fig. 98, greatly magnified; _a_, antennæ; _b_, maxillæ, and their
palpi, _c_; _d_, mandibles; the latter, with the labium, which is not
shown in the figure, forming the acute beak) is much compressed, and
there are minute wing-pads, instead of wings, present in some species.
[Illustration: 98. Flea, magnified.]
[Illustration: 99. Larva of Flea.]
Dr. G. A. Perkins, of Salem, has succeeded in rearing in considerable
numbers from the eggs, the larvæ of this flea. The larvæ (Fig. 99, much
enlarged; _a_, antenna; _b_, the terminal segments of the abdomen), when
hatched, are half a line in length. The body is long, cylindrical, and
pure white, with thirteen segments exclusive of the head, and provided
with rather long hairs. It is very active in its movements, and lives on
blood clots, remaining on unswept floors of out-houses, or in the straw
or bed of the animals they infest. In six days after the eggs are laid
the larvæ appear, and in a few days after leaving the egg they mature,
spin a rude cocoon, and change to pupæ, and the perfect insects appear
in about ten days. A good authority states that the human flea does not
exist in America. We never saw a specimen in this country.
A practical point is how to rid dogs of fleas. As a preventive measure,
we would suggest the frequent sweeping and cleansing of the floors of
their kennels, and renewing the straw or chips composing their
beds,--chips being the best material for them to sleep upon. Flea
afflicted dogs should be washed every few days in strong soapsuds, or
weak tobacco or petroleum water.
A writer in "Science-Gossip" recommends the "use of the Persian Insect
Destroyer, one package of which suffices for a good sized dog. The
powder should be well rubbed in all over the skin, or the dog, if small,
can be put into a bag previously dusted with the powder; in either case
the dog should be washed soon after."
[Illustration: 100. Chique.]
One of the most serious insect torments of the tropics of America is the
Sarcopsylla penetrans, called by the natives the Jigger, Chigoe, Bicho,
Chique, or Pique (Fig. 100, enlarged; a, gravid female, natural size).
The female, during the dry season, bores into the feet of the natives,
the operation requiring but a quarter of an hour, usually penetrating
under the nails, and lives there until her body becomes distended with
eggs, the hind-body swelling out to the size of a pea; her presence
often causes distressing sores. The Chigoe lays about sixty eggs,
depositing them in a sort of sac on each side of the external opening of
the oviduct. The young develop and feed upon the swollen body of the
parent flea until they mature, when they leave the body of their host
and escape to the ground. The best preventive is cleanliness and the
constant wearing of shoes or slippers when in the house, and of boots
when out of doors.
[Illustration: The Willow Gall Fly.]
CHAPTER VIII.
THE BORERS OF OUR SHADE TREES.
In no way can the good taste and public spirit of our citizens be better
shown than in the planting of shade trees. Regarded simply from a
commercial point of view one cannot make a more paying investment than
setting out an oak, elm, maple or other shade tree about his premises.
To a second generation it becomes a precious heirloom, and the planter
is duly held in remembrance for those finer qualities of heart and head,
and the wise forethought which prompted a deed simple and natural, but a
deed too often undone. What an increased value does a fine avenue of
shade trees give to real estate in a city? And in the country the single
stately elm rising gracefully and benignantly over the wayside cottage,
year after year like a guardian angel sending down its blessings of
shade, moisture and coolness in times of drought, and shelter from the
pitiless storm, recalls the tenderest associations of generation after
generation that go from the old homestead.
Occasionally the tree, or a number of them, sicken and die, or linger
out a miserable existence, and we naturally after failing to ascribe the
cause to bad soil, want of moisture or adverse atmospheric agencies,
conclude that the tree is infested with insects, especially if the bark
in certain places seems diseased. Often the disease is in streets
lighted by gas, attributed to the leakage of the gas. Such a case has
come up recently at Morristown, New Jersey. An elm was killed by the Elm
borer (Compsidea tridentata), and the owner was on the point of suing
the Gas Company for the loss of the tree from the supposed leakage of a
gas pipe. While the matter was in dispute, a gentleman of that city took
the pains to peel off a piece of the bark and found, as he wrote me,
"great numbers of the larvæ of this beetle in the bark and between the
bark and the wood, while the latter is 'tattooed' with sinuous grooves
in every direction and the tree is completely girdled by them in some
places. There are three different sizes of the larvæ, evidently one, two
and three years old, or more properly six, eighteen and thirty months
old." The tree had to be cut down.
Dr. Harris, in his "Treatise on Injurious Insects," gives an account of
the ravages of this insect, which we quote: "On the 19th of June, 1846,
Theophilus Parsons, Esq., sent me some fragments of bark and insects
which were taken by Mr. J. Richardson from the decaying elms on Boston
Common, and among the insects I recognized a pair of these beetles in a
living state. The trees were found to have suffered terribly from the
ravages of these insects. Several of them had already been cut down, as
past recovery; others were in a dying state, and nearly all of them were
more or less affected with disease or premature decay. Their bark was
perforated, to the height of thirty feet from the ground, with numerous
holes, through which insects had escaped; and large pieces had become so
loose, by the undermining of the grubs, as to yield to slight efforts,
and come off in flakes. The inner bark was filled with burrows of the
grubs, great numbers of which, in various stages of growth, together
with some in the pupa state, were found therein; and even the surface of
the wood, in many cases, was furrowed with their irregular tracks. Very
rarely did they seem to have penetrated far into the wood itself; but
their operations were mostly confined to the inner layers of the bark,
which thereby became loosened from the wood beneath. The grubs rarely
exceed three-quarters of an inch in length. They have no feet, and they
resemble the larvæ of other species of Saperda, except in being rather
more flattened. They appear to complete their transformations in the
third year of their existence.
"The beetles probably leave their holes in the bark during the month of
June and in the beginning of July, for, in the course of thirty years, I
have repeatedly taken them at various dates, from the fifth of June to
the tenth of July. It is evident, from the nature and extent of their
depredations, that these insects have alarmingly hastened the decay of
the elm trees on Boston Mall and Common, and that they now threaten
their entire destruction. Other causes, however, have probably
contributed to the same end. It will be remembered that these trees
have greatly suffered, in past times, from the ravages of canker-worms.
Moreover, the impenetrable state of the surface soil, the exhausted
condition of the subsoil, and the deprivation of all benefit from the
decomposition of accumulated leaves, which, in a state of nature, the
trees would have enjoyed, but which a regard for neatness has
industriously removed, have doubtless had no small influence in
diminishing the vigor of the trees, and thus made them fall
unresistingly a prey to insect devourers. The plan of this work
precludes a more full consideration of these and other topics connected
with the growth and decay of these trees; and I can only add, that it
may be prudent to cut down and burn all that are much infested by the
borers."
[Illustration: 101. Elm Tree Beetle.]
The Three-toothed Compsidea (Fig. 101), is a rather flat-bodied, dark
brown beetle, with a rusty red curved line behind the eyes, two stripes
on the thorax, and a three-toothed stripe on the outer edge of each wing
cover. It is about one-half an inch in length.
[Illustration: 102. Elm Tree Borer.]
The larva (Fig. 102) is white, subcylindrical, a little flattened, with
the lateral fold of the body rather prominent; the end of the body is
flattened, obtuse, and nearly as wide at the end as at the first
abdominal ring. The head is one-half as wide as the prothoracic ring,
being rather large. The prothoracic ring, or segment just behind the
head, is transversely oblong, being twice as broad as long; there is a
pale dorsal corneous transversely oblong shield, being about two-thirds
as long as wide, and nearly as long as the four succeeding segments;
this plate is smooth, except on the posterior half, which is rough, with
the front edge irregular and not extending far down the sides. Fine
hairs arise from the front edge and side of the plate, and similar hairs
are scattered over the body and especially around the end. On the upper
side of each segment is a transversely oblong ovate roughened area, with
the front edge slightly convex, and the hinder slightly arcuate. On the
under side of each segment are similar rough horny plates, but arcuate
in front, with the hinder edge straight.
It differs from the larva of the Linden tree borer (Saperda vestita) in
the body being shorter, broader, more hairy, with the tip of the abdomen
flatter and more hairy. The prothoracic segment is broader and flatter,
and the rough portion of the dorsal plates is larger and less
tranversely ovate. The structure of the head shows that its generic
distinctness from Saperda is well founded, as the head is smaller and
flatter, the clypeus being twice as large, and the labrum broad and
short, while in S. vestita it is longer than broad. The mandibles are
much longer and slenderer, and the antennæ are much smaller than in S.
vestita.
[Illustration: 103. Linden Tree Beetle.]
[Illustration: 104. Linden Tree Borer.]
The Linden tree borer (Fig. 103) is a greenish snuff-yellow beetle, with
six black spots near the middle of the back; and it is about
eight-tenths of an inch in length, though often smaller. The beetles,
according to Dr. Paul Swift, as quoted by Dr. Harris, were found (in
Philadelphia) upon the small branches and leaves on the 28th day of May,
and it is said that they come out as early as the first of the month,
and continue to make their way through the back of the trunk and large
branches during the whole of the warm season. They immediately fly into
the top of the tree, and there feed upon the epidermis of the tender
twigs, and the petioles of the leaves, often wholly denuding the latter,
and causing the leaves to fall. They deposit their eggs, two or three in
a place, upon the trunk or branches especially about the forks, making
slight incisions or punctures for their reception with their strong
jaws. As many as ninety eggs have been taken from a single beetle. The
grubs (Fig. 104, _e_; _a_, enlarged view of the head seen from above;
_b_, the under view of the same: _c_, side view, and _d_, two rings of
the body enlarged), hatched from these eggs, undermine the bark to the
extent of six or eight inches, in sinuous channels, or penetrate the
solid wood an equal distance. It is supposed that three years are
required to mature the insect. Various expedients have been tried to
arrest their course, but without effect. A stream, thrown into the tops
of trees from the hydrant, is often used with good success to dislodge
other insects; but the borer-beetles, when thus disturbed, take wing and
hover over the trees till all is quiet, and then alight and go to work
again. The trunks and branches of some of the trees have been washed
over with various preparations without benefit. Boring the trunk near
the ground and putting in sulphur and other drugs, and plugging, have
been tried with as little effect.
[Illustration: 105. Poplar Tree Borer.]
The city of Philadelphia has suffered grievously from this borer.
[Illustration: 106. Broad-necked Prionus.]
Dr. Swift remarks, in 1844, that "the trees in Washington and
Independence Squares were first observed to have been attacked about
seven years ago. Within two years it has been found necessary to cut
down forty-seven European lindens in the former square alone, where
there now remain only a few American lindens, and these a good deal
eaten." In New England this beetle should be looked for during the first
half of June.
[Illustration: 107. Larva of the Plain Saperda.]
The Poplar tree is infested by an other species of Saperda (S.
calcarata). This is a much larger beetle than those above mentioned,
being an inch or a little more in length. It is grey, irregularly
striped, with ochre, and the wing-covers end in a sharp point. The grub
(Fig. 105 _a_; _b_, top view of the head; _e_, under side) is about two
inches long and whitish yellow. It has, with that of the Broad-necked
Prionus (P. laticollis of Drury, Fig. 106, adult and pupa), as Harris
states, "almost entirely destroyed the Lombardy poplar in this vicinity"
(Boston). It bores in the trunks, and the beetle flies by night in
August and September. We also figure the larva of another borer (Fig.
107 _c_; _a_, top view of the head; _b_, under side; _e_, dorsal view of
an abdominal segment; _d_, end of the body, showing its peculiar form),
the Saperda inornata of Say, the beetle of which is black, with ash gray
hairs, and without spines on the wing-covers. It is much smaller than
any of the foregoing species, being nine-twentieths of an inch in
length. Its habits are not known. We also figure the Locust and Hickory
borer (Fig. 108; _a_, larva; _b_, pupa), which has swept off the locust
tree from New England. The beautiful yellow banded beetles are very
abundant on the flowers of the golden rod in September.
[Illustration: 108. Locust Borer.]
FOOTNOTES:
[Footnote 4: The External and Internal Parasites of Man and Domestic
Animals. By Prof. A. E. Verrill, 1870. We are indebted to the author for
the use of this and the figures of the Bot fly of the horse, the turkey,
duck and hog louse, the Cattle tick, the itch insect and mange insect of
the horse.]
CHAPTER IX.
CERTAIN PARASITIC INSECTS.
The subject of our discourse is not only a disagreeable but too often a
painful one. Not only is the mere mention of the creature's name of
which we are to speak tabooed and avoided by the refined and polite, but
the creature itself has become extinct and banished from the society of
the good and respectable. Indeed under such happy auspices do a large
proportion of the civilized world now live that their knowledge of the
habits and form of a louse may be represented by a blank. Not so with
some of their great-great-grandfathers and grandmothers, if history,
sacred and profane, poetry,[5] and the annals of literature testify
aright; for it is comparatively a recent fact in history that the louse
has awakened to find himself an outcast and an alien. Among savage
nations of all climes, some of which have been dignified with the apt,
though high sounding name of Phthiriophagi, and among the Chinese and
other semi-civilized peoples, these lords of the soil still flourish
with a luxuriance and rankness of growth that never diminishes, so that
we may say without exaggeration that certain mental traits and fleshly
appetites induced by their consumption as an article of food may have
been created, while a separate niche in our anthropological museums is
reserved for the instruments of warfare, both offensive and defensive,
used by their phthiriophagous hunters. Then have we not in the very
centres of civilization the poor and degraded, which are most faithfully
attended lay these revolting satellites!
But bantering aside, there is no more engaging subject to the naturalist
than that of animal parasites. Consider the great proportion of animals
that gain their livelihood by stealing that of others. While a large
proportion of plants are more or less parasitic, they gain, thereby in
interest to the botanist, and many of them are eagerly sought as the
choicest ornaments of our conservatories. Not so with their zoölogical
confréres. All that is repulsive and uncanny is associated with them,
and those who study them, though perhaps among the keenest intellects
and most industrious observers, speak of them without the limits of
their own circle in subdued whispers or under a protest, and their works
fall under the eyes of the scantiest few. But the study of animal
parasites has opened up new fields of research, all bearing most
intimately on those two questions that ever incite the naturalist to the
most laborious and untiring diligence--what is life and its origin? The
subjects of the alternation of generations, or parthenogenesis, of
embryology and biology, owe their great advance, in large degree, to the
study of such animals as are parasitic, and the question whether the
origin of species be due to creation by the action of secondary laws or
not, will be largely met and answered by the study of the varied
metamorphoses and modes of growth, the peculiar modification of organs
that adapt them to their strange modes of life, and the consequent
variation in specific characters so remarkably characteristic of those
animals living parasitically upon others.[6]
With these considerations in view surely a serious, thoughtful, and
thorough study of the louse, in all its varieties and species, is
neither belittling nor degrading, nor a waste of time. We venture to
say, moreover, that more light will be thrown on the classification and
morphology of insects by the study of the parasitic species, and other
degraded, wingless forms that do not always live parasitically,
especially of their embryology and changes after leaving the egg, than
by years of study of the more highly developed insects alone. Among
Hymenoptera the study of the minute Ichueumons, such as the
Proctotrupids and Chalcids, especially the egg-parasites; among moths
the study of the wingless canker-worm moth and Orgyla; among Diptera the
flea, bee louse, sheep tick, bat tick, and other wingless flies; among
Coleoptera, the Meloë, and singular Stylops and Xenos; among Neuroptera,
the snow insect, Boreus, the Podura (Fig. 109) and Lepisma, and
especially the hemipterous lice, will throw a flood of light on these
prime subjects in philosophical entomology.
[Illustration: 109. Podura.]
Without farther apology, then, and very dependent on the labors of
others for our information, we will say a few words on some interesting
points in the natural history of lice. In the first place, how does the
louse bite? It is the general opinion among physicians, supported by
able entomologists, that the louse has jaws, and bites. But while the
bird lice (Mallophaga) do have biting jaws, whence the Germans call them
skin-eaters (_pelzfresser_), the mouth parts of the genus Pediculus, or
true louse, resemble in their structure those of the bed-bug (Fig. 110),
and other Hemiptera. In its form the louse closely resembles the
bed-bug, and the two groups of lice, the Pediculi and Mallophaga, should
be considered as families of Hemiptera, though degraded and at the base
of the hemipterous series. The resemblance is carried out in the form of
the egg, the mode of growth of the embryo, and the metamorphosis of the
insect after leaving its egg.
[Illustration: 110. Bed-bug.]
Schiödte, a Danish entomologist, has, it seems to us, forever settled
the question as to whether the louse bites the flesh or sucks blood, and
decides a point interesting to physicians, _i.e._, that the loathsome
disease called phthiriasis is a nonentity. From this source not only
many living in poverty and squalor are said to have died, but also men
of renown, among whom Denny in his work on the Anoplura, or lice, of
Great Britain, mentions the name of "Pheretima, as recorded by
Herodotus, Antiochus Epiphanes, the Dictator Sylla, the two Herods, the
Emperor Maximian, and Phillip the Second." Schiödte, in his essay "On
Phthirius, and on the Structure of the Mouth in Pediculus" (Annals and
Magazine of Natural History, 1866, page 213), says that these statements
will not bear examination, and that this disease should be placed on the
"retired list," for such a malady is impossible to be produced by simply
blood-sucking animals, and that they are only the disgusting attendants
on other diseases. Our author thus describes the mouth parts of the
louse.
"Lice are no doubt to be regarded as bugs, simplified in structure and
lowered in animal life in accordance with their mode of living as
parasites, being small, flattened, apterous, myopic, crawling and
climbing, with a conical head, moulded as it were to suit the rugosities
of the surface they inhabit, provided with a soft, transversely furrowed
skin, probably endowed with an acute sense of feeling, which can guide
them in that twilight in which their mode of life places them. The
peculiar attenuation of the head in front of the antennæ at once
suggests to the practised eye the existence of a mouth adapted for
suction. This mouth differs from that of the Hemiptera (bed-bug, etc.)
generally, in the circumstance that the labium is capable of being
retracted into the upper part of the head, which therefore presents a
little fold, which is extended when the labium is protruded. In order to
strengthen this part, a flat band of chitine is placed on the under
surface, just as the shoemaker puts a small piece of gutta-percha into
the back of an India-rubber shoe; as, however, the chitine is not very
elastic, this band is rather thinner in the middle, in order that it may
bend and fold a little when the skin is not extended by the lower lip.
The latter consists, as usual, of two hard lateral pieces, of which the
fore ends are united by a membrane so that they form a tube, of which
the interior covering is a continuation of the elastic membrane in the
top of the head; inside its orifice there are a number of small hooks,
which assume different positions according to the degree of protrusion;
if this is at its highest point the orifice is turned inside out, like a
collar, whereby the small hooks are directed backwards, so that they can
serve as barbs. These are the movements which the animal executes after
having first inserted the labium through a sweat-pore. When the hooks
have got a firm hold, the first pair of setæ (the real mandibles
transformed) are protruded; these are, towards their points, united by a
membrane so as to form a closed tube, from which, again, is inserted the
second pair of setæ, or maxillæ, which in the same manner are
transformed into a tube ending in four small lobes placed crosswise. It
follows that when the whole instrument is exserted, we perceive a long
membranous flexible tube hanging down from the labium, and along the
walls of this tube the setiform mandibles and maxillæ in the shape of
long narrow bands of chitine. In this way the tube of suction can be
made longer or shorter as required, and easily adjusted to the thickness
of the skin in the particular place where the animal is sucking, whereby
access to the capillary system is secured at any part of the body. It is
apparent, from the whole structure of the instrument, that it is by no
means calculated on being used as a sting, but is rather to be compared
to a delicate elastic probe, in the use of which the terminal lobes
probably serve as feelers. As soon as the capillary system is reached,
the blood will at once ascend into the narrow tube, after which the
current is continued with increasing rapidity by means of the pulsation
of the pumping ventricle and the powerful peristaltic movement of the
digestive tube."
[Illustration:[7]111. Mouth of the Louse.]
If we compare the form of the louse (Fig. 112, Pediculus capitis, the
head louse; Fig. 113, P. vestimenti, the body louse) with the young
bed-bug as figured by Westwood (Modern Classification of Insects, ii,.p.
475) we shall see a very close resemblance, the head of the young Cimex
being proportionally larger than in the adult, while the thorax is
smaller, and the abdomen is more ovate, less rounded; moreover the body
is white and partially transparent.
[Illustration: 113. Body Louse.]
[Illustration: 112. Head Louse.]
Under a high power of the microscope specimens treated with diluted
potash show that the mandibles and maxillæ arise near each other in the
middle of the head opposite the eyes, their bases slightly diverging.
Thence they converge to the mouth, over which they meet, and beyond are
free, being hollow, thin bands of chitine, meeting like the maxillæ, or
tongue, of butterflies to form a hollow tube for suction. The mandibles
each suddenly end in a curved, slender filament, which is probably used
as a tactile organ to explore the best sites in the flesh of their
victim for drawing blood. On the other hand the maxillæ, which are much
narrower than the mandibles, become rounded towards the end, bristle
like, and tipped with numerous exceedingly fine barbs, by which the bug
anchors itself in the flesh, while the blood is pumped through the
mandibles. The base of the large, tubular labium, or beak, which
ensheathes the mandibles and maxillæ, is opposite the end of the clypeus
or front edge of the upper side of the head, and at a distance beyond
the mouth equal to the breadth of the labium itself. The labium, which
is divided into three joints, becomes flattened towards the tip, which
is square, and ends in two thin membranous lobes, probably endowed with
a slight sense of touch. On comparing these parts with those of the
louse, it will be seen how much alike they are with the exception of the
labium, a very variable organ in the Hemiptera. From the long sucker of
the Pediculus, to the stout chitinous jaws of the Mallophaga, or bird
lice, is a sudden transition, but on comparing the rest of the head and
body it will be seen that the distinction only amounts to a family one,
though Burmeister placed the Mallophaga among the Orthoptera
(grasshoppers and crickets) on account of the mandibles being adapted
for biting. It has been a common source of error to depend too much upon
one or a single set of organs. Insects have been classified on
characters drawn from the wings, or the number of the joints of the
tarsi, or the form of the mouth parts. We must take into account in
endeavoring to ascertain the limits of natural groups, as the internal
anatomy and the embryology and metamorphosis of insects, before we can
hope to obtain a natural classification.
The family of bird lice is a very extensive one, embracing many genera,
and several hundred species. One or more species infest the skin of all
our domestic and wild mammals and birds, some birds sheltering beneath
their feathers four or five species of lice. Before giving a hasty
account of some of our more common species; we will give a sketch of the
embryological history of the lice, with special reference to the
structure of the mouth parts.
[Illustration: 114. Embryo of the Louse.]
[Illustration: 115. Mouth Parts of the Louse.]
The eggs (Fig. 114, egg of the head louse) are long, oval, somewhat
pear-shaped, with the hinder end somewhat pointed, while the anterior
end is flattened, and bears little conical micropyles (_m_, minute
orifices for the passage of the spermatozoa into the egg), which vary in
form in the different species and genera; the opposite end of the egg is
provided with a few bristles. The female attaches her eggs to the hairs
or feathers of her host.
[Illustration: 116. Mouth Parts of the Louse.]
[Illustration: 118. Mouth Parts of Louse.]
[Illustration: 117. Mouth Parts of Louse.]
After the egg has been fertilized by the male, the blastoderm, or
primitive skin, forms, and subsequently two layers, or embryonal
membranes, appear; the outer is called the amnion (Fig. 114, _am_),
while the inner visceral membrane (_db_) partially wraps the rude form
of the embryo in its folds. The head (_vk_) of the embryo is now
directed towards the end of the egg on which the hairs are situated;
afterwards the embryo revolves on its axis and the head lies next to the
opposite end of the egg. Eight tubercles bud out from the under side of
the head, of which the foremost and longest are the antennæ (_as_),
those succeeding are the mandibles, maxillæ, and second maxillæ, or
labium. Behind them arise six long, slender tubercles forming the legs,
and the primitive streak rudely marks the lower wall of the thorax and
abdomen not yet formed. Figure 115 represents the head and mouth parts
of the embryo of the same louse; _vk_ is the forehead, or clypeus;
_ant_, the antennæ; _mad_, the mandibles; _max_1, the
first pair of maxillæ, and _max_^2, the second pair
of maxillæ, or labium. Figure 116 represents the mouth parts of the
same insect a little farther advanced, with the jaws and labium
elongated and closely folded together. Figure 117 represents the same
still farther advanced; the mandibles (_mad_) are sharp, and resemble
the jaws of the Mallophaga; and the maxillæ (_max_^1) and labium
(_max_^2) are still large, while afterwards the labium becomes nearly
obsolete. Figure 118 represents a front view of the mouth parts of a
bird louse, Goniodes; _lb_, is the upper lip, or labrum, lying under the
clypeus; _mad_, the mandibles; max, the maxillæ; _l_, the lyre-formed
piece; and _pl_, the "plate."
[Illustration: 119. Louse of Cow.]
We will now describe some of the common species of lice found on a few
of our domestic animals, and the mallophagous parasites occurring on
certain mammals and birds. The family Pediculina, or true lice, is
higher than the bird lice, their mouth parts, as well as the structure
of the head, resembling the true Hemiptera, especially the bed bug. The
clypeus, or front of the head, is much smaller than in the bird lice,
the latter retaining the enlarged forehead of the embryo, it being in
some species half as large as the rest of the head.
All of our domestic mammals and birds are plagued by one or more species
of lice. Figure 119 represents the Hæmatopinus vituli, which is brownish
in color. As the specimen figured came from the Burnett collection of
the Boston Society of Natural History, together with those of the goat
louse, the louse of the common fowl, and of the cat, they are
undoubtedly naturalized here. Quite a different species is the louse of
the hog (H. suis, Fig. 120).
[Illustration: 120. Louse of Hog.]
The remaining parasites belong to the skin-biting lice, or Mallophaga,
and I will speak of the several genera referred to in their natural
order, beginning with the highest form and that which is nearest allied
to Pediculus.
[Illustration: 121. Louse of Domestic Fowl.]
The common barn-yard fowl is infested by a louse that we have called
Goniocotes Burnettii (Fig. 121), in honor of the late Dr. W. I. Burnett,
a young and talented naturalist and physiologist, who paid more
attention than any one else in this country to the study of these
parasites, and made a large collection of them, now in the museum of the
Boston Society of Natural History. It differs from the G. hologaster of
Europe, which lives on the same bird, in the short second joint of the
antennæ, which are also stouter; and in the long head, the clypeus being
much longer and more acutely rounded; while the head is less hollowed
out at the insertion of the antennæ. The abdomen is oval, and one-half
as wide as long, with transverse, broad, irregular bands along the edges
of the segments. The mandibles are short and straight, two toothed. The
body is slightly yellowish, and variously streaked and banded with
pitchy black. The duck is infested by a remarkably slender form (Fig.
122, Philopterus squalidus). Figure 123 represents the louse of the cat,
and another species (Fig. 124) of the same genus (Trichodes) lives upon
the goat.
The most degraded genus is Gyropus. Mr. C. Cook has found Gyropus ovalis
of Europe abundant on the Guinea pig. A species is also found on the
porpoise; an interesting fact, as this is the only insect we know of
that lives parasitically on any marine animal.
[Illustration: 122. Duck Louse.]
The genus Goniodes (Fig. 125, G. stylifer, the turkey louse) is of great
interest from a morphological and developmental point of view, as the
antennæ are described and figured by Denny as being "in the males
cheliform (Fig. 126, _a_, male; _b_, female); the first joint being very
large and thick, the third considerably smaller, recurved towards the
first, and forming a claw, the fourth and fifth very small, arising
from the back of the third." He farther remarks, that "the males of this
[which lives on the turkey] and all the other species of Goniodes, use
the first and third joints of the antennæ with great facility, acting
the part of a finger and thumb." The antennæ of the females are of the
ordinary form. This hand-like structure, is, so far as we know, without
a parallel among insects, the antennæ of the Hemiptera being almost
uniformly filiform, and from two to nine-jointed. The design of this
structure is probably to enable the male to grasp its consort and also
perhaps to cling to the feathers, and thus give it a superiority over
the weaker sex in its advances towards courtship. Why is this advantage
possessed by the males of this genus alone? The world of insects, and of
animals generally abounds in such instances, though existing in other
organs, and the developmentist dimly perceives in such departures from a
normal type of structure, the origin of new generic forms, whether due
at first to a seemingly accidental variation, or, as in this instance,
perhaps, to long use as prehensile organs through successive generations
of lice having the antennæ slightly diverging from the typical
condition, until the present form has been developed. Another generation
of naturalists will perhaps unanimously agree that the Creator has thus
worked through secondary laws, which many of the naturalists of the
present day are endeavoring, in a truly scientific and honest spirit of
inquiry, to discover.
[Illustration: 124. Louse of the Goat.]
[Illustration: 123. Louse of the Cat.]
In their claw or leg-like form these male antennæ also repeat in the
head, the general form of the legs, whose prehensile and grasping
functions they assume. We have seen above that the appendages of the
head and thorax are alike in the embryo, and the present case is an
interesting example of the unity of type of the jointed appendages of
insects, and articulates generally.
[Illustration: 120. Antennæ of Goniodes.]
Another point of interest in these degraded insects is, that the process
of degradation begins either late in the life of the embryo or during
the changes from the larval to the adult, or winged state. An instance
of the latter may be observed in the wingless female of the canker worm,
so different from the winged male; this difference is created after the
larval stage, for the caterpillars of both sexes are the same, so far as
we know. So with numerous other examples among the moths. In the louse,
the embryo, late in its life, resembles the embryos of other insects,
even Corixa, a member of a not remotely allied family. But just before
hatching the insect assumes its degraded louse physiognomy. The
developmentist would say that this process of degradation points to
causes acting upon the insect just before or immediately after birth,
inducing the retrogression and retardation of development, and would
consider it as an argument for the evolution of specific forms by causes
acting on the animal while battling with its fellows in the struggle for
existence, and perhaps consider that the metamorphoses of the animal
within the egg are due to a reflex action of the modes of life of the
ancestors of the animal on the embryos of its descendants.
[Illustration: 125. The Turkey Louse.]
FOOTNOTES:
[Footnote 5:
Ha! whare ye gaun, ye crowlin ferlie!
Your impudence protects you sairly:
I canna say but ye struift rarely,
Owre gauze and lace;
Tho' faith, I fear ye dine but sparely
On sic a place.
Ye ugly, creepin, blastic wormer,
Detested, shunn'd by saunt and sinner,
How dare ye set your fit upon her
Sae fine a lady!
Gae somewhere else and seek your dinner
On some poor body.
(To a Louse.--Burns.)]
[Footnote 6: We notice while preparing this article that a journal of
Parasitology has for some time been issued in Germany--that favored land
of specialists. It is the "Zeitschrift fur Parasitenkunde," edited by
Dr. E. Hallier and F A. Zurn. 8vo, Jena.]
[Footnote 7: Figure 111 represents the parts of the mouth in a large
specimen of _Pediculus_ vestimenti, entirely protruding, and seen from
above, magnified one hundred and sixty times; aa, the summit of the head
with four bristles on each side; _bb_, the chitinous band, and _c_, the
hind part of the lower lip, such as they appear through the skin by
strong transmitted light; _dd_, the foremost protruding part of the
lower lip (the haustellum); _ee_, the hooks turned outwards; _f_, the
inner tube of suction, slightly bent and twisted; the two pairs of jaws
are perceived on the outside as thin lines; a few blood globules are
seen in the interior of the tube.]
CHAPTER X.
THE DRAGON FLY.
Were we to select from among the insects a type of all that is savage,
relentless, and bloodthirsty, the Dragon fly would be our choice. From
the moment of its birth until its death, usually a twelve-month, it
riots in bloodshed and carnage. Living beneath the waters perhaps eleven
months of its life, in the larva and pupa states, it is literally a
walking pitfall for luckless aquatic insects; but when transformed into
a fly, ever on the wing in pursuit of its prey, it throws off all
concealment, and reveals the more unblushingly its rapacious character.
Not only do its horrid visage and ferocious bearing frighten children,
who call it the "Devil's Darning-needle," but it even distresses older
persons, so that its name has become a byword. Could we understand the
language of insects, what tales of horror would be revealed! What
traditions, sagas, fables, and myths must adorn the annals of animal
life regarding this Dragon among insects!
To man, however, aside from its bad name and its repulsive aspect, which
its gay trappings do not conceal, its whole life is beneficent. It is a
scavenger, being like that class ugly and repulsive, and holding
literally, among insects, the lowest rank in society. In the water, it
preys upon young mosquitoes and the larvæ of other noxious insects. It
thus aids in maintaining the balance of life, and cleanses the swamps of
miasmata, thus purifying the air we breathe. During its existence of
three or four weeks above the waters, its whole life is a continued good
to man. It hawks over pools and fields and through gardens, decimating
swarms of mosquitoes, flies, gnats, and other baneful insects. It is a
true Malthus' delight, and, following that sanguinary philosopher, we
may believe that our Dragon fly is an entomological Tamerlane or
Napoleon sent into the world by a kind Providence to prevent too close a
jostling among the myriads of insect life.
We will, then, conquer our repugnance to its ugly looks and savage mien,
and contemplate the hideous monstrosity,--as it is useless to deny that
it combines the graces of the Hunchback of Notre Dame and Dickens'
Quilp, with certain features of its own,--for the good it does in
Nature.
Even among insects, a class replete with forms the very incarnation of
ugliness and the perfection of all that is hideous in nature, our Dragon
fly is most conspicuous. Look at its enormous head, with its beetling
brows, retreating face, and heavy under jaws,--all eyes and teeth,--and
hung so loosely on its short, weak neck, sunk beneath its enormous
hunchback,--for it is wofully round-shouldered,--while its long, thin
legs, shrunken as if from disease, are drawn up beneath its breast, and
what a hobgoblin it is!
Its gleaming wings are, however, beautiful objects. They form a broad
expanse of delicate parchment-like membrane drawn over an intricate
network of veins. Though the body is bulky, it is yet light, and easily
sustained by the wings. The long tail undoubtedly acts as a rudder to
steady its flight.
These insects are almost universally dressed in the gayest colors. The
body is variously banded with rich shades of blue, green, and yellow,
and the wings give off the most beautiful iridescent and metallic
reflections.
During July and August the various species of Libellula and its allies
most abound. The eggs are attached loosely in bunches to the stems of
rushes and other water-plants. In laying them, the Dragon fly, according
to Mr. P. R. Uhler's observations, "alights upon water-plants, and,
pushing the end of her body below the surface of the water, glues a
bunch of eggs to the submerged stem or leaf. Libellula auripennis I have
often seen laying eggs, and I think I was not deceived in my observation
that she dropped a bunch of eggs into the open ditch while balancing
herself just a little way above the surface of the water. I have, also,
seen her settled upon the reeds in brackish water with her abdomen
submerged in part, and there attaching a cluster of eggs. I feel pretty
sure that L. auripennis does not always deposit the whole of her eggs at
one time, as I have seen her attach a cluster of not more than a dozen
small yellow eggs. There must be more than one hundred eggs in one of
the large bunches. The eggs of some of the Agrions are bright
apple-green, but I cannot be sure that I have ever seen them in the very
act of oviposition. They have curious habits of settling upon leaves and
grass growing in the water, and often allow their abdomens to fall below
the surface of the water; sometimes they fly against the surface, but I
never saw what I could assert to be the projecting of the eggs from the
body upon plants or into the water. The English entomologists assert
that the female Agrion goes below the surface to a depth of several
inches to deposit eggs upon the submerged stems of plants." The Agrions,
however, according to Lucaze Duthiers, a French anatomist, make, with
the ovipositor, a little notch in the plant upon which they lay their
eggs.
[Illustration: 127. Under side of head of Diplax, with the labium or
mask fully extended. _x_, _x_', _x_''the three subdivisions of the
labium. _y_, the maxillæ or second pair of jaws.]
These eggs soon hatch, probably during the heat of summer. The larva is
very active in its habits, being provided with six legs, attached to the
thorax, on the back of which are the little wing-pads, or rudimentary
wings. The large head is provided with enormous eyes, while a pair of
simple, minute eyelets (ocelli) are placed near the origin of the small
bristle-like feelers, or antennæ. Seen from beneath, instead of the
formidable array of jaws and accessory organs commonly observed in most
carnivorous larvæ, we see nothing but a broad, smooth mask covering the
lower part of the face; as if from sheer modesty our young Dragon fly
was endeavoring to conceal a gape. But wait a moment. Some unwary insect
comes within striking distance. The battery of jaws is unmasked, and
opens upon the victim. This mask (Fig. 127) is peculiar to the young,
or larva and pupa of the Dragon fly. It is the labium, or under lip
greatly enlarged, and armed at the broad spoon-shaped extremity (Fig.
127, _x_) with two sharp hooks, adapted for seizing and retaining its
prey. At rest, the terminal half is so bent up as to conceal the face,
and thus the creature crawls about, to all appearance, the most innocent
and lamb-like of insects.
[Illustration: 128. Abdominal valves; _a_, side view.]
Not only does the immature Dragon fly walk over the bottom of the pool
or stream it inhabits, but it can also leap for a considerable distance,
and by a most curious contrivance. By a syringe-like apparatus lodged in
the end of the body, it discharges a stream of water for a distance of
two or three inches behind it, thus propelling the insect forwards. This
apparatus combines the functions of locomotion and respiration. There
are, as usual, two breathing pores (stigmata) on each side of the
thorax. But the process of breathing seems to be mostly carried on in
the tail. The tracheæ are here collected in a large mass, sending their
branches into folds of membrane lining the end of the alimentary canal,
and which act like a piston to force out the water. The entrance to the
canal is protected by three to five triangular horny valves (Fig. 128,
9, 10, 128 _a_, side view), which open and shut at will. When open, the
water flows in, bathing the internal gill-like organs, which extract the
air from the water, which is then suddenly expelled by a strong muscular
effort.
[Illustration: 129. Agrion; _b_, False Gill of Larva.]
In the smaller forms, such as Agrion (A. saucium, Fig. 129; Fig. 129
_b_, side view of false gill, showing but one leaf), the respiratory
leaves, called the tracheary, or false-gills, are not enclosed within
the body, but form three broad leaves, permeated by tracheæ, or
air-vessels. They are not true gills, however, as the blood is not
aerated in them. They only absorb air to supply the tracheæ, which
aerate the blood only within the general cavity of the body. These false
gills also act as a rudder to aid the insect in swimming.
It is interesting to watch the Dragon flies through their
transformations, as they can easily be kept in aquaria. Little, almost
nothing, is known regarding their habits, and any one who can spend the
necessary time and patience in rearing them, so as to trace up the
different stages from the larva to the adult fly, and describe and
figure them accurately, will do good service to science.
[Illustration: 130. Pupa of Cordulia.]
Mr. Uhler states that at present we know but little of the young stages
of our species, but the larva and pupa of the Libellulas may be always
known from the Æschnas by the shorter, deeper and more robust form, and
generally by their thick clothing of hair. Figure 130 represents the
pupa of Cordulia lateralis, and figure 131 that of a Dragon fly referred
doubtfully to the genus Didymops. For descriptions and figures of other
forms the reader may turn to Mr. Louis Cabot's essay "On the Immature
State of the Odonata," published by the Museum of Comparative Zoology at
Cambridge.
[Illustration: 131. Pupa of Didymops?]
The pupa scarcely differs from the larva, except in having larger
wing-pads (Fig. 132). It is still active, and as much of a gourmand as
ever. When the insect is about to assume the pupa state, it moults its
skin. The body having outgrown the larva skin, by a strong muscular
effort a rent opens along the back of the thorax, and the insect having
fastened its claws into some object at the bottom of the pool, the pupa
gradually works its way out of the larva-skin. It is now considerably
larger than before. Immediately after this tedious operation, its body
is soft, but the crust soon hardens. This change, with most species,
probably occurs early in summer.
[Illustration: 132. Pupa of Æschna.]
When about to change into the adult fly, the pupa climbs up some plant
near the surface of the water. Again its back yawns wide open, and from
the rent our Dragon fly slowly emerges. For an hour or more, it remains
torpid and listless, with its flabby, soft wings remaining motionless.
The fluids leave the surface, the crust hardens and dries, rich and
varied tints appear, and our Dragon fly rises into its new world of
light and sunshine a gorgeous, but repulsive being. Tennyson thus
describes these changes in "The Two Voices":--
To-day I saw the Dragon fly
Come from the wells where he did lie.
An inner impulse rent the veil
Of his old husk: from head to tail
Came out clear plates of sapphire mail.
He dried his wings; like gauze they grew;
Through crofts and pastures wet with dew
A living flash of light he flew.
Of our more common, typical forms of Dragon flies, we figure a few,
commonly observed during the summer. The three-spotted Dragon fly
(Libellula trimaculata), of which figure 133 represents the male, is so
called from the three dark clouds on the wings of the female. But the
opposite sex differs in having a dark patch at the front edge of the
wings, and a single broad cloud just beyond the middle of the wing.
Libellula quadrimaculata, the four-spotted Dragon fly (Fig. 134), is
seen on the wing in June, flying through dry pine woods far from any
standing water.
[Illustration: 133. Libellula trimac
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