(_Deromyia_)
This creature is very savage and pounces upon even large sized insects,
paralyzing them instantly by a sting of its poisoned beak.
[Illustration]
THE CULEX MOSQUITO
(_Culex sp._)
The flat white wings of this long-legged creature, vibrating rapidly in
the air, make what everyone will agree is the most annoying sound in the
world. They make the mosquitos' hum. The cigar-shaped abdomen is striped
like a convict's jacket. As a boy there was to me a peculiar fascination
in watching that abdomen pinken and turn red along its sides as it filled
with blood sucked from my hand.
The large eyes compose almost the entire head of a mosquito and in some
species they are of an emerald green hue. Straight out in front, close
together, curved downward at the tip, are two antennæ furnished with
delicate hairs arranged like a bottle brush. With these the creature hears
the love hum of its mate and probably scents also the neighborhood of any
warm-blooded animal.
Were this a male, instead of a female, these hairs would be much longer
and there would be many more of them--they are the smelling organs of the
creature and the hearing organs, too, being set into vibration by sound
waves of a certain rate. It is important to remember this, for only the
females are bloodthirsty. The long, slender proboscis projecting from the
head, downward, is furnished with sharp, piercing stylets which, by
working up and down, cut their way through the skin. Ordinarily the males
and females both are content with sap of plants and fruits as their food,
and blood does not seem to be a necessary part of their diet. It is
curious that what is supposed to be merely an acquired habit of the female
only, of an insignificant little fly, should mean so much to mankind.
Just why a mosquito bite is poisonous is still a matter of question--the
suggestion has been made that since both male and female really live on
plants, the fluid which the female injects is for the purpose of
preventing the plant juice from coagulating during the process of sucking
and merely happens to be irritating to warm-blooded animals.
There are three hundred different species of these creatures already
described and fortunately this one, a species of culex, is not
responsible, so far as known, for the carrying of any human disease.
[Illustration]
ONE OF THE HARMLESS ANOPHELES MOSQUITOS
(_Anopheles punctipennis_, Say)
The malarial mosquito, so called, has spotted wings, but otherwise it
looks quite like this harmless form from Maryland. This whole tribe of
Anopheles differs from the Culex in the length of its mouth feelers, which
project from the base of the proboscis and appear in the photograph almost
as long as the proboscis itself, whereas in a photograph of the Culex it
would appear so short as to seem merely a thickening of the base of the
proboscis.
The wildest fancy of the Arabian story-teller is lacking in imagination
compared with the story which the facts of modern science have woven about
these tiny representatives of the fly family.
Who could imagine that just because the lady mosquitos, tiring of their
usual meal of ripe bananas and plant juices, acquired the habit of sucking
blood, vast regions would be devastated and beings millions of times their
size would die by thousands. And this, too, not through any real fault of
the tiny creatures themselves, but just because some of the persons whose
blood they sucked had microscopic wiggling things living in their blood
corpuscles, which crawled into the soft throat glands of the mosquito and
waited there for a chance to get out into the blood channels of some other
human beings.
When one pictures the grief of desolated homes, death-bed agonies of
tossing fever patients, the quarantined vessels at anchor in tropical
harbors, yellow flagged, with crews dead or dying, the streets of deserted
houses from which all life has gone forever through yellow fever and
malaria, there is something ghastly in the picture of the winged lady
mosquitos flitting airily from pale-faced patients to ruddy-cheeked happy
people, unwitting carriers of death.
No conquest of science seems more wonderful in its simplicity and more
remarkable in its importance than the discovery that the glands at the
base of the mosquito's bill can become diseased and harbor a microscopic
parasite, and transform this merely buzzing, annoying insect into one of
the most dangerous creatures alive. To Dr. L. O. Howard, the pioneer of
economic entomology, is due the great credit for first showing how this
creature can be killed by the use of kerosene on the stagnant waters where
the females lay their eggs.
[Illustration]
ONE OF THE BEE FLIES
(_Sparnopolius fulvus_, Wied.)
No butterfly or any other creature of the air could be more beautiful than
this dream of early summer. The black velvet body, into which the sunlight
sank and disappeared, the fringe of golden hairs along its sides, the
steel gray, myriad-facet eyes of which its head was made, and the
delicately formed wings, so thin that the light in passing through them
was refracted into rainbow tints, made it seem to me more beautiful than
almost any of those gorgeous forms of insect life which sometimes fill the
clearings in Brazilian forests.
It does seem strange that such a thing as this should live its other life
a parasitic grub within the larva of some caterpillar, or in the egg-case
of some grasshopper; but so it seems to do. It spends its childhood as a
disease, and its mating days as a dainty fly among the nectar-bearing
flowers.
[Illustration]
ANOTHER OF THE BEE FLIES
(_Spogostylum simson_, Fab.)
Where you see the carpenter bee you always see these bee flies waiting for
the bee to go away from home. When the mother bee is out the female fly
goes into the cell of the bee and lays her egg, and when her larva hatches
out it eats up the bee's larva.
[Illustration]
LARGE SYRPHID FLY
(_Melesia virginiensis_, Dru.)
This is a very bright-colored syrphid fly often seen soaring in shadowy
places, but what he is doing we do not know. He stays poised in the air
and is one of the most beautiful flies we have.
The larvæ of some of the smaller syrphid flies feed upon the larvæ of
other insects, aphids in particular; but the larva of this one has never
been seen, at least it has never been recognized.
[Illustration]
NOT A HOUSE FLY
(_Archytas aterrima_, Des.)
This portrait of one of the many species of fly, not a house fly, however,
is as different as it is possible to be from the maggot from which it
grew. The eggs of the mother fly, deposited in some decaying animal
matter, hatch in a few days, and out of these eggs come maggots with
rudimentary legs and looking like beasts from another world entirely. In a
few days more they reach the limit of their growth, and stop, the tissues
break down to a mush and out of this mush-like substance are formed flies
with wings and sucking, trunklike mouths just like their mothers. The
maggots have no sexual organs, and yet, out of the creamy mass of cells,
the sexual organs of the flies are formed as though directed by a force as
certain in its effects as the law of gravitation.
We have been so intent on killing the fly and so afraid of it as the great
carrier of human diseases that we have lost sight of one phase of its
character, so to speak. Think of having under our eyes animals like these
dipteras from which you can breed a new generation in twelve days! And
would it not be strange if, from studying the fly, we should learn the
meaning of heredity and sexuality, for this is one of the places where the
scientists of the day are at work on the problem of inheritance, that
problem which, when elucidated, is likely to make more changes in the
world of humankind than almost anything which has so far been discovered.
The bearing of the fly on the welfare of the world is one of the most
spectacular developments of modern times and a tribute to the value of
knowing the minutest details of the world in which we live.
[Illustration]
THE HORSE FLY
(_Tabanus atratus_, Forst.)
The head of the horse fly appears to be all eyes, and it is no wonder that
we can so seldom take it by surprise.
Below the oblong, compound eyes are the sharp mouthparts, which in the
female are provided with lancets, which enable her to puncture the skin of
warm-blooded animals and suck their blood. It is curious that the female
should have such habits, while the males are content to lap up nectar from
the flowers.
This jet black, loud-buzzing creature flew into my laboratory and made so
much noise that I was forced to kill her. This photograph of her is nine
times her real diameter.
She belongs to a large and important family of flies, whose females make
the lives of men and animals miserable in many parts of the world by their
bites, which form most annoying wounds.
[Illustration]
A GREEN-HEADED HORSE FLY
(_Tabanus punctifer_, O. S.)
There are nearly two hundred species of horse flies in North America, and
this creature represents one of the commonest forms. It doubtless hatched
out somewhere on the edge of the brook which flows through my place in
Maryland, and its larval self fed upon other insect larvæ or on the snails
and slugs it found itself among.
The bands of iridescent green and copper and purple across its enormous
eyes made it a beautiful creature to look upon.
We never used to think the bite of flies was anything worse than annoying,
but recently, since we have discovered the danger of letting the germs of
disease into the blood streams of our bodies, we have come to see the
ghastly possibilities which lie in the piercing mouthparts of these flies.
They suck the blood of animals whose blood streams may be swarming with
disease germs, and then fly directly to our houses and puncture our skins
with a beak covered with these germs which slip off into our veins.
Until we know that the diseases of the birds, and field mice, the coons
and 'possums, and all other warm-blooded beasts of a locality are harmless
to us, or that it is impossible to transmit them to human beings, it is
best to look upon these blood-sucking creatures as winged hypodermic
syringes laden with disease.
It has been suggested that the horse flies carry anthrax, and their bites
sometimes cause malignant pustules. They are also under suspicion as
carriers of infantile paralysis.
FEATHERED INSECTS
(_Lepidoptera_)
These are peculiarly the feathered fliers of the insect world, for their
wings and their bodies, too, are covered with most remarkable one-celled
feathers or scales of gorgeous colors which make of some of them the most
brilliant of all living things.
Just what these scales are for is not entirely clear, and will not be,
perhaps, until we understand the purpose of the gorgeous coloring itself.
There is a theory that these scales help to grip the air in flying.
It is a curious coincidence that one of these gorgeously colored creatures
should furnish mankind with the material for his own most gaily colored
raiment. The silkworm is one of the very few domesticated insects, so to
speak, of all the hundreds of thousands of insect species in existence,
and a hundred millions of dollars is paid every year for the delicate silk
threads unraveled from countless millions of cocoons which the silkworm
larvæ have laboriously fashioned around themselves.
To many people, moths are known by what they leave behind--holes in the
winter woolens; and butterflies are to them, somehow, things of the
sunlight and the summertime. It is worth while to know that these great
families of butterflies and moths are not by any means divided equally,
that for every family of butterflies there are at least nine of the moths
and that the butterflies form but a small proportion of the gaily colored
insects of the fields.
Perhaps it makes but little difference to the public, who call them all
alike, but it is as easy to tell a butterfly from a moth as it is to tell
a lizard from a snake, for all the butterflies have club-shaped feelers,
or antennæ, whereas the moths do not, and any child of six can learn to
tell the two apart.
No butterfly or moth in its winged state can harm us or our plants. It has
no jaws, but keeps itself alive by sucking nectar from the flowers or
juices from the fruits or other parts. Its other self, its larva, however,
can cause no end of damage. One inconspicuous, brownish form, the
codling-moth, no larger than my thumb nail, costs apple growers about ten
million dollars every year, while the cabbage moth, the clothes moth, the
cutworm and the dreaded gipsy-moth are only a few examples of a gigantic
army of voracious larvæ against which man has been struggling ever since
he first began to plant seeds in the ground or set out trees for fruit.
[Illustration]
LARVA OF THE SWALLOW-TAIL BUTTERFLY OF THE SPICE-BUSH
(_Papilio troilus_, Linn.)
Is this, I wonder, an insect make-believe, a caterpillar mask, as it were,
to frighten away enemies? The black and white eye-spots are not real eyes,
but to a bird they doubtless seem so. Its real eyes are inconspicuous
points at each side of the head, too small to appear in the photograph.
Few of as stop to think, as the beautiful swallow-tail butterfly, gorgeous
in its black and yellow painted wings, flits by us, that it is made of
sassafras and spice-bush leaves gathered together and ground up. This
monster is a leaf-eating creature, its purpose being the accumulation of
food material out of which is made inside of it the gorgeous swallow-tail
butterfly. It feeds on sassafras and spice-bush leaves, and when the time
arrives makes a nest for itself by fastening the edges of a leaf together.
In this nest it passes the winter. When spring comes it breaks open the
gray shell of the chrysalis, unfolds a pair of black and gold wings with
long tails to them, and flies away in the sunshine in search of flowers
and a mate. It is then no more like this monster than an eagle is like a
hippopotamus, yet after it has flown about, sucking nectar through its
long beak, it mates and lays a mass of eggs, out of which hatch again
these strange, weird beings.
[Illustration]
FORE PART OF A BROWN BUTTERFLY
(_Agrynnis cybele_, Fab.)
It is hard to realize that this is the portrait of the head and fore part
of a beautiful brown butterfly.
Its head is almost all taken up with the gigantic eyes, which are composed
of thousands of tiny facets. The long, trunklike mouth with which it sucks
the nectar from the flowers is coiled up like a watch spring. Like
shingles on a roof, the scales are fastened in tiers over the broad
surface of the wings stretched over the stiff ribs or framework.
The white spots are made by hundreds of white scales and the brown
blotches by brown scales, and what these scales are for nobody seems to
know. Perhaps they help to grip the wind, for they have running lengthwise
of them deep and parallel corrugations so small and fine that were a
single scale as large as a lady's opened fan these corrugations would
represent its sticks.
The caterpillar from which this splendid creature came is black, with
branching spines, and feeds at night on violets and other plants.
The graceful beauty of the butterfly, its seemingly happy existence, its
life among the flowers, where it sips the nectar that the flowers provide,
are all a part of common knowledge.
The real life of the butterfly, however, is not so pleasant as we think.
Have you ever found a butterfly hanging beneath a leaf on a cold summer
morning drenched with dew and stiff with cold? Have you ever seen one
trying to cross a field in a rain-storm and observed it vainly attempting
to navigate the conflicting air currents? Where do they roost at night and
on rainy days? Where do they come from and what becomes of them? These are
matters which it has often taken men years to find out, and even now there
are many thousands of species of butterflies which are known only by a
preserved specimen caught in its flight by the net of some collector.
[Illustration]
YELLOW BUTTERFLY
(_Colias philodice_, Gdt.)
The Doctor Jekyll and Mr. Hyde is so complete between the butterfly which
flits over the cabbage patch and the velvety green worm that eats holes in
the leaves of the cabbages that it is no wonder that for centuries no
connection between the two careers of these creatures, seemingly so far
apart, was suspected. In general it is true that no moth or butterfly is
injurious to plants except in its larval stage, and herein has lain the
clever deception which has doubtless protected these gay mating creatures
of the air from the systematic attacks of man until quite recent times.
This picture shows what every boy and girl should know, that every
butterfly has club-shaped feelers or antennæ.
It is said of certain species of yellow butterflies that the males give
off a pleasing, aromatic odor which is exhaled from the front wings
through hundreds of minute, slender scales--scales quite different from
those with which the wings and body are covered. This scent, which is so
strong that it can be detected by even our blunted olfactory organs if we
rub the wings between thumb and forefinger, is supposed to attract the
females in some way that is little understood. As among these particular
butterflies the male seeks out its mate, it is difficult to understand why
it should be the male which has the perfume, since it does not serve to
tell the female where her mate is to be found. The inference is that in
some way the perfume charms the female.
In some species it is the females which give off an odor, and in either
case the distances over which these odors extend and are detected by the
males or females respectively are analogous to the inconceivable reach of
wireless telegraphy. And who knows but the mechanism of these creatures is
set to respond to the swiftly traveling ions which make wireless
telegraphy possible?
[Illustration]
A BABY OF THE SKIPPER BUTTERFLY
(_Eudamus tityrus_, Fab.)
There is something fascinatingly strange to me in the babies of the winged
butterflies, and I wonder why so many people have an aversion for them?
Can there be an instinctive fear of anything that crawls, or is not this
fear taught us by unthinking persons? The child is not afraid of the
wide-mouthed naked little birds in the nest, or the little blind pink
mice, and certainly they are no more innocent looking than the brilliant
colored larva of the butterflies or moths.
What helpless things these babies are! They cannot fly, they cannot fight,
they can barely see, and even their gait is a hobbled one.
Their business is to eat, and their jaws must keep busy pretty constantly
to fill their stomachs with leaf fragments, for the greater part of the
soft, flabby bodies is stomach. They are males and females but which they
are you cannot tell until they turn into butterflies.
Along this creature's sides, like portholes in an ocean liner, are the
breathing pores, nine in number. Most animals which live on land take air
in through a single opening into a great cavity through which the blood
circulates and is purified, but the caterpillars, and all insects in fact,
instead of circulating their blood in and out of a pair of lungs, have,
running through their bodies, a labyrinth of air passages, all connected
with the outside air by means of breathing pores.
This caterpillar's eyes are poor affairs, and unless you look closely you
will not find them, for they are merely a few raised spots, like blisters,
beneath the skin on either side of its jaws.
It has, like the spiders, a spinneret and a reservoir of liquid silk with
which, as it outgrows its baby state, it can spin its own arbor of tough
silk fibers and hide itself from view while it is changing to a butterfly.
If in late summer you will put one of these creatures in a tumbler and
watch it for a day or two, you can see it plainly through the glass
pouring out the liquid silk in a steady stream, waving its head from side
to side. The silk comes from a spinneret which is just behind the jaws and
is about the color of thin starch paste. The way it loops back upon itself
and flows in curves reminds me most forcibly of the way the pastry cook,
with frosting in a paper cornucopia, writes one's name upon a birthday
cake.
[Illustration]
A BUTTERFLY'S MUMMY CASE
One of the most marvelously beautiful of all living creatures lies waiting
within this case for the resurrection day, when growth shall split open
this polished casket and it shall feel the wings, close packed for weeks,
unfold, and, stretching to a hundred times their size, bear it away into
the sunshine.
Did the Pharaohs, I wonder, or their wise men, seeing this, model their
mummy cases after those which the butterflies make?
This is the chrysalis of a butterfly, that wonder of poets since poetry
began, that life-stage of the butterfly which our faith and hopes make
comparable to our own rest in the tomb from which man in all ages has
believed there came a resurrection and another life, no more to be
compared with this than the butterfly's own existence among the flowers is
to be likened to his crawling one upon the leaves. And because the minds
of many men in seeking to understand, have broken down this beautiful
analogy by finding that there is no real decay within the chrysalis, we
must not hence conclude they have done more than brush away a fancied
similarity. The mystery remains.
If you should open this butterfly mummy case, lay bare the mummy as it
were, you would find a pair of wings in process of formation, a head, a
curled-up sucking beak, legs and embryo antennæ, that is, providing it
were near the resurrection time. If not, and you had broken in too early,
the greater part within the case would be a semi-fluid mass of broken down
cell tissues from which the legs and wings and all the other parts are
made.
The portholes along the side lead deep into the body and are probably as
necessary to the growing butterfly inside as they are to it when it once
emerges. The chrysalis must breathe.
To many people there is much confusion as to what is a chrysalis and what
a real cocoon. Every cocoon is a silken case spun by the caterpillar in
which it can securely hide while it changes first into the chrysalis and
then into its winged and final form. This chrysalis, or pupa, forms within
the body skin and some caterpillars do not spin a cocoon at all, but
merely rest somewhere away from view, until this strange process has been
completed within the out-worn shell. This photograph is of such a
chrysalis.
[Illustration]
A MOTH
We commonly picture the moths and butterflies with their wings spread out
or else upright in the air, but many moths trail their wings when they
alight and escape our notice by their quiet colors. Walk through the grass
and you will frighten thousands which, when they alight again, you cannot
for the life of you detect upon the grass stems.
There are hardly any butterflies that trail their wings like this and not
one of them has beautiful feathery antennæ.
[Illustration]
NOT GOOD TO EAT
Have you never wondered at the temerity with which certain of these
slow-moving, helpless creatures expose themselves to the attacks of their
enemies? In a world so full of hungry, winged beings it does seem strange,
and when the markings are black and white or some such striking color in
contrast with the leaves or bark the temerity seems even more
extraordinary, until one learns the simple fact--these creatures are not
very good to eat.
Not good enough to eat! Supposing that the fly and the mosquito were
equipped with some flavor distasteful to the insectivorous birds; if
cattle were not good to eat, nor sheep, nor hogs, nor any living,
breathing things, what a change there would be in a world like ours! And
yet to chemists there is very little difference between some compounds
that are good to eat and others that are deadly poison, no greater than
that between the poison bitter almond and the sweet one of our dinner
table.
One cannot help but wonder why it is that when the border-land twixt food
and poison is so narrow in the chemistry of the living cell that every
creature has not equipped itself with prussic acid enough to preserve
itself from its enemies.
While this protection holds good against many predaceous creatures, there
are various birds and even snakes that have found this particular
caterpillar not too bad to eat.
[Illustration]
A HAIRY SPECTACLE
(_Euchætes egle_, Dru.)
Many of the caterpillars of our fields are striking in their form and
color. This one could easily be seen some distance off and might to birds
and others of its enemies be what the skunk is to its enemy the dog--a
thing to shun.
In the luxuriance of its "plumage" it, in some respects, reminds one of
those fantastic forms of fowls produced by close line breeding, the
Hudans, for example, or the long-tailed roosters of Japan.
Few creatures that we have photographed have been more beautiful than this
black and white larva with its hairs in graceful tufts all over its body.
What it eats or what its other self is like, I have not yet been able to
find out.
[Illustration]
AN UNKNOWN CATERPILLAR
Creatures like this, when they come walking down a garden path, are so
striking and so gracefully weird that one would think their forms
deserving of more study than they get. There is a reason for this, though,
that is not hard to find; they are such transient creatures. A few days in
the egg, a week or two as caterpillars, and they pass into their cocoons
to emerge as moths or butterflies, and of the two weeks when they are
caterpillars, the first part of the time they are too small to make much
impression upon us.
Then too, you cannot collect and keep them as you can the butterflies or
beetles, in fact this strange horned beast is still unnamed because its
carcass shriveled and faded until it bore so little resemblance to its
living self that it could not be identified. It is quite unlike the
hickory borer or horned devil, being dark red-brown in color. It takes a
skilled taxidermist entomologist to squeeze them out, blow up the skin and
mount them in a case, and that is the only way to keep these forms, unless
we have found another way in these photographs of them.
[Illustration]
A CATERPILLAR DEVOURED BY A FUNGUS
(_Apantesis nais attacked by Empusa sp._, Dru.)
One cold morning in early autumn I saw this caterpillar lying so still on
the grass stem on which you see it that I thought I could photograph it
before it woke up. I picked the grass panicle, but when I came to look
closely at the caterpillar I found it was a shriveled corpse and that
there were gaping wounds in its sides, filled with the threads of a
parasitic fungus; a fungus familiar to me through one of its distant
relatives which I spent six months of my life studying, and which lives in
the intestines of the frog. There is something ghastly about the slow but
resistless working of a fungus in the body of a caterpillar. One cannot
help wondering where the plant got in and how the caterpillar felt about
it. Was there the horror of finding that it could not be dislodged and the
hopelessness of the struggle against it and the impending death and
shortening of an already very brief existence?
So these, and seemingly all other creatures, have their diseases, and the
studies which men have made and are making upon them in all parts of the
world are helping us to understand the causes of those which attack and
often conquer human beings.
NERVE-WINGED INSECTS
(_Neuroptera_)
There was a time before all living things were classified, when there were
no groups of plants or animals or insects. It is something to be proud of
that man has grouped the likes together and formed, out of the chaos of
living species, a system into which most of them can go like letters into
pigeonholes. Is it any wonder that with half a million species in this
insect world there should be some groups in which the species forming them
seem to have very little likeness to each other? The nerve-winged insects
seem to form just such a group, for the principal things they have in
common seem to be peculiar nerve-veined wings and blood-thirsty habits.
If we could be quite sure that dragon-flies and scorpion-flies and
caddis-flies preyed only upon our foes, we could say with more confidence
than we do now, that they are our friends and not our enemies, and that
men should find some means by which to help increase the number of them in
the world.
It is conceivable that, as we learn more about them, they may take a much
more important place in public esteem, just as insectivorous birds are
doing. Perhaps they will come to be protected and their breeding places
guarded by the drainage engineers.
[Illustration]
THE DRAGON-FLY
No dragon of legend could be more blood-thirsty or terrible than this.
With four wings like the supporting planes of an aerodrome, it can fly as
fast as a railway train. With thousands of eyes crowded together like
cells in a honeycomb, forming eye masses that cover most of its head, it
can see in all directions at once. With massive jaws and teeth as sharp as
needle points, it can pierce and crush the strongest shell of its prey.
With its long-jointed spiny legs held out in front like a basket, it
rushes through the air, catches and devours its prey and lets the carcass
fall to the ground, all without slackening its terrible speed.
It is hard to realize, as you watch this swiftly moving dragon of the air,
that it has spent the first stage of its life as a slowly crawling, ugly
water monster lying in wait among the reeds and grasses for some
unsuspecting water bug or larva to pass by.
The female, as she skims the surface of some pool, drops into the water
her clumps of dragon eggs, a thousand at a time, and from these are born
the ugly water dragons, which, when come of age, grow wings and, crawling
to the surface, split their old skins open, unfold and dry their closely
packed wings, and dart away into the sunshine to prey upon the other
creatures of the air.
[Illustration]
THE DRAGON-FLY AND ITS VICTIM
(_Macromia sp._)
Who would suspect, as one of these dragon-flies darts by him on the
roadway, that every few minutes its jaws are crunching some helpless
insect caught in its flight?
When I caught the dragon-fly whose picture is shown here, I held him by
the wings, and, catching a fly that buzzed about the table, dropped it in
his claws. Without a moment's hesitation his mouth opened wide and closed
upon the fly. I watched it disappear underneath his great upper lip and
almost fancied I could hear its shell crack as the powerful jaws and lower
lips turned it around and around in the mouth. A few seconds only, and the
sucking throat had drawn out all the blood and the lips threw out a
ball-like mass made up of the fly's wings, legs and crushed body skeleton.
Then it opened again for more.
One entomologist has said that in two hours a dragon-fly will eat at least
forty house flies, and Doctor Howard says that if starved for food it will
eat up its own body.
No doubt these dragons of the air are to be counted as among our greatest
friends, and in places in the East where life is made a burden by that
humming, stinging pest, the mosquito, its presence in great numbers helps
amazingly in keeping down the day-flying forms of that insect. It has gone
into the Hawaiian Islands with the mosquito and has learned there to breed
in the water found on the leaves of lilies growing on dry land.
Perhaps someone will find a way to domesticate this creature and make it
live upon the house flies around the house. As a first step, Needham has
fed the larvæ on bits of meat.
Sharpe, the British authority, has observed a dragon-fly returning again
and again to the same bush, and Westwood believes he saw the same
individual hawking for several weeks together over the same small pond.
[Illustration]
DRAGON-FLY NYMPH MASKED
(_Libellulid_)
As Kellogg says, it must, indeed, be worth more than a week of study in
the house to see just once the transformation of one of these mud dragons
from the bottom of a pond into a beautiful dragon of the air,--a
dragon-fly.
Of all the strange, weird monsters with which I have ever had to deal,
this water one seems somehow weirdest. It reminds me of those
sandy-colored, deep-sea fishes which, snuggling under the sand of the sea
bottom, wait for their prey to come along and then dart out and seize them
with their powerful jaws.
The mud dragon has a mask which, for the purpose, is certainly the most
effective thing one can imagine. Its victims must be greatly surprised to
see the mask drop, revealing a sheep-like nose, mouth, and lips, while the
mask itself opening out and splitting down the middle, becomes a pair of
needle-margined, powerful claws so strong that even fishes are sometimes
caught and held by them.
It is strange to think of this dragon concealing its claws by making a
shield of them to cover its ugly face while it waits in ambush for its
game.
Its eyes and body are the color of mud and must be very hard to see.
This photograph shows the mask in place, the grinning mouth a long curved
slit across the face, while resting on the ground, as one would rest one's
elbow on the table, is the powerful claw arm, so strong that you would
find it difficult to pull the mask away, or having done so to keep it
down.
[Illustration]
DRAGON-FLY NYMPH UNMASKED
(_Libellulid_)
Pulled down from the mud dragon's sheep-nosed face, the mask is resting on
the ground. It can be stretched out much further and also opened up to
form a pair of powerful claws. Along the edge of the mask is a fringe of
inward-pointing spines like those which edge the leaf margins of a venus
flytrap. The eyes are large and many-faceted and form the blunt-pointed
corners of its head.
The under-water battles in which these mud dragons, or dragon-fly nymphs,
take part must be something terrible. It is recorded that in Hungary
50,000 young fishes were put into a pond in which enormous numbers of
these nymphs occurred and only fifty-four fishes survived. One is not
surprised to learn, too, that they will eat each other up.
On the whole, however, it is doubtful if between the flies and other
injurious insects which the dragon-flies destroy in the air, and those
larvæ of mosquitos which the water nymphs destroy in the ponds, there is
any other family of insects toward which man should feel more indebted
than toward the family of the odontata or dragon-flies.
[Illustration]
AN ABANDONED DRAGON CASE
(_Libellulid_)
From this muddy outworn shell, left to decay at the bottom of a pool,
there came, sometime last summer, a gorgeous, four-winged dragon-fly. A
little after dawn, what was once this water nymph or mud dragon, tired
perhaps of its mud existence, ready anyway for the transformation, crawled
up out of the water upon some stone or stick and waited there for its back
to split open up and down. It pulled its soft, boneless legs from their
cases, now lying along the abandoned shell, its wings closely packed
together from the two cases on its back and its head and jaws from out the
broken head shell. Even every air passage running through its body shed
its parchment lining.
Soft and helpless it crawled away into the grass to wait until its wet,
soft outer skeleton should harden and make it possible for the powerful
wing muscles to pull against it and for the broad wing films to dry and
straighten out. By noon the transformation was doubtless quite complete,
and flitting across the pond went the recent inhabitant of this dragon-fly
case.
[Illustration]
THE DAMSEL FLY
(_Agrion maculatum_, Beauvois)
Most insects' legs are made to walk with, but those of the dragon-fly are
not. They are bunched together so near the head that when the creature
alights it can do little more than cling to what it lights upon. Instead,
the legs, with their spines, form a perfect basket, open towards the
front, and thus become the organs with which flies are caught.
This damsel fly, as it is called, is smaller and more delicate than the
dragon-fly with quite a different head. It inhabits shrubby woodland and
is not often seen. Some of its tropical relatives are creatures of
extraordinary fragility and delicacy.
Its wings, which move in perfect unison, although distinct, are operated
by such ingenious mechanical devices within the body as to have long ago
suggested a flying machine, and it is strange how like a dragon-fly
Professor Langley's aerodrome, the first of them all, does look, although
of course the aerodrome's wings were rigid.
One realizes what enormous eyes these dragon-flies have when one begins to
compare them with the size of the head.
[Illustration]
THE LACE-WINGED FLY AND THE APHIS LION
(_Chrysopa sp._)
So fragile and delicate does this creature appear that one can but wonder
how it exists in the jungle of the grass. It has a disagreeable odor, it
is said, and this is perhaps the reason that it holds its own, for it
flies so slowly and is so conspicuous that it would otherwise fall a prey
to every insectivorous bird and dragon-fly.
Its other self is the Aphis Lion, a wingless but very active creature
which hunts for plant lice and when it finds one punctures it with its
mandibles, raises it in the air and lets the blood trickle down into its
mouth. It sucks eggs, too, and, shameless creature that it is, it sucks
those of its own species, or would, at least, if the mother instinct had
not taught the winged females to lay their eggs on the ends of long,
slender, stiff stems which the undiscriminating larvæ cannot climb, much
as a human mother puts the pot of jam on the top shelf where the children
cannot get it.
[Illustration]
THE WINGED ANT LION
(_Myrmeleon immaculatus_, De G.)
As with many of these monsters, it is the other self, the larva of the
winged ant lion, which is the fascinating study.
This winged form merely lays the egg from which hatches out the soft,
spindle-shaped young with jaws like pincers. This little creature at once
marks out a tiny circle in some dry, sandy place, and begins to dig a
pitfall for its prey, the ants.
By pitching the sand with its broad, flat head, just as a man who digs a
well would pitch out shovelfuls of dirt, the young ant lion excavates a
tiny crater in the sand and hides itself in the crater's pit with its
pincers sticking upwards through the fine, loose sand.
Any child who has jumped into his father's oat bin and tried to climb up
the hillside of tumbling grain, knows how hard it is to get out. If he
will imagine a hidden monster waiting with jaws opened at the bottom, he
will have some sympathy for the unlucky ant which, slipping upon the
rolling sand of the ant lion's crater slides slowly towards its
pit--helped perhaps by dirt thrown on it by the ant lion.
There seems to be no escape, and once within reach, the pincers close on
it, and along their grooved inner faces, helped down by special
tongue-like licking organs, the blood trickles and is guided to the mouth
and thence into the stomach of the lion. And, curiously enough, this
stomach is the only organ of digestion which the ant lion has. The stomach
has no outlet and everything that is not digested must wait within it
until the change of life brings on this winged state, when, like a tiny
egg, the gathered excreta of the weeks and even months of feeding is
thrown out from the body. Perhaps this strange structure of the beast has
something to do with the fact that it can live six months at least without
a particle of food.
[Illustration]
THE SCORPION FLY
(_Panorpa confusa_, Westw.)
When the scorpion fly, standing still, raises above its head that pair of
pincers which forms its tail, it seems almost like some two-headed
monstrosity.
It is interesting to know that the great Aristotle knew these insects and
thought of them as winged scorpions. It is only the males which have these
curious tails.
One might easily mistake the long snout for that of some sucking insect,
but at the very tip there are two oblong, plate-shaped jaws, each armed
with two very sharp teeth which enable the creature to live a carnivorous
existence. Although little is yet known about it, the scorpion fly
appears, like a hyena, to live chiefly on dead animal matter, although it
has been seen to attack injured or helpless insects.
[Illustration]
A SOLDIER TERMITE
(_Termes flavipes_, Koll.)
Although too poor a photograph, perhaps, to be worthy of a place in this
collection, I have a sentimental reason for its reproduction here, for it
brings to mind the days I spent in Java lying flat on the ground studying
the mushroom gardens of its tropical relatives.
There are few more interesting creatures than these termites. They have
been mushroom eaters and mushroom growers for thousands of years. They
have their kings and queens, their workers and their soldiers, and they
build gigantic caverns and tall mounds out of earth and half-digested
wood.
They tear to pieces and reduce to powder the dead trees of the tropical
forests.
Their nymphs, the young kings and queens, are winged and perform a
marriage flight, then, tearing off their own wings, they settle down to
form a home of dirt and start a new and numerous colony.
They seem to be upon a higher plane of social life than are the true ants,
with which they are not in any way related, for the members of a species
seem all to be quite friendly towards each other even though they may come
from widely different nests. This is never true of ants.
Their queens are strange, egg-laying machines as large as a man's thumb,
and they lay an egg a second for nobody knows how long.
The workers shun the light and make long, covered ways of mud in which
they go from place to place. With their untiring energy they honeycomb the
building timbers of houses and ships in the tropics, making mere hollow
shells of them, and so causing disasters of all kinds.
Some of their soldiers have mandibles so strong and sharp as to drive away
all animals and make them formidable enemies of man, and some have squirt
guns in their heads with which they spray their enemies with an obnoxious
fluid.
This tiny representative is all we have in Maryland, but though so small
and quiet in his habits he does great work among the pine stumps of my
place. The stump of any pine that is felled one year can be kicked out the
next, honeycombed with the chambered runways of this creature. Beware lest
any pine timbers of your house are near the ground and become infested
with termites.
THE STINGING INSECTS
(_Hymenoptera_)
This order is another one in which it takes an entomologist to see the
characteristic likenesses in the various species of insects composing it.
They all have membranous wings, and all the females have either a saw, an
ovipositor or a sting at the tip of the abdomen. One may say, indeed, that
practically all the stinging insects are in this order.
Bees, wasps, ants, gall flies, saw flies, and ichneumon flies are
Hymenoptera, the ants coming into this membranous winged order because the
males and females are winged for the marriage flight, and lose them only
after this is over.
This is considered the highest order of insects because it contains
members with the most marvelously developed instincts of any creatures in
the world, insects whose habits, skill and industry excite our admiration
and wonder. Whether they live in colonies with highly developed social
states, or whether they live the lives of solitary hermits, their industry
and sacrifice to keep alive and perpetuate their kind, are things that
make us wonder whether, after all, we have the right to call ourselves the
most altruistic of living creatures.
It is around these Hymenoptera that centers the great question of what
instinct is, and how it differs from intelligence. We cannot help but feel
that it is memory of some kind, not necessarily like the memory of our own
brains, but a race memory, transmitted in the almost microscopic egg laid
by the mother before she dies.
The instinct of the bee, or wasp, or ant is quite a different kind of
thing from reason. Since these creatures have stood still in their
development, or at least have changed but little since tertiary times, it
is quite possible that their present state represents the highest type of
evolution along the lines of instinct. The power to reason, to meet a new
emergency, are things which came much later in the development of the
world, and man, the creature having them in the highest degree, seems
destined to control all other creatures in the end.
[Illustration]
THE PORTRAIT OF A BALD-FACED HORNET
(_Vespula maculata_, Linn.)
I wish I could convey to you my sensation when, in hunting for the focus
on my ground glass, this creature burst upon my sight. It was as though,
exploring in some strange land, I suddenly stood face to face with a beast
about which no schoolbook had ever taught me anything. It peered at me out
of the gloom of imperfect focus, and it took me some time to realize that
I was looking into the eyes of a bald-faced hornet.
There is no wild creature in the northern United States that a man will
run away from so fast as from a bald-faced hornet.
At the tip of her flexible armor-plated abdomen is the poison-fed stiletto
with which she drives off enemies from the nest or paralyzes her prey.
Her six powerful legs are spined to help her, no doubt, in climbing over
the smooth surfaces of flowers and twigs. She has two kinds of eyes--three
lens-shaped ones on top of her head and two marvelous compound ones
composed of hundreds of little lenses, which take up half the head. Just
what she uses each kind for is still unknown.
From her forehead hang ringed antennæ, which doubtless are the organs with
which she scents the presence of her prey, and they may also help her find
her way about.
Her massive jaws lie below her eyes and look like shears with jagged
edges; they are meant for crushing, not for grinding, and with these she
tears to pieces bits of wood and cements the particles together with the
sticky secretion of her salivary glands, making thus the combs and shelter
of her wood-pulp paper nest.
She is an undeveloped female, but with the professional care of a baby's
nurse she tends her sister hornets in the nest. On the wing, from daylight
to dark, she scours the country for the flies and other insects with which
to feed the young. Of all the fly-destroyers which frequent the house she
is perhaps the most efficient, pouncing upon the flies with murderous
voracity, tearing off their heads and legs and wings, and macerating their
bodies to a pulp to feed the hungry grub-like baby hornets which are
hatching out in the paper nest over the front door. Her life, and the life
of every other worker, is ended by the autumn, and it is left to a few of
the young queens to carry on the species.
Does this picture represent, I wonder, one of the nightmare visions which
haunt the dreams of baby flies?
[Illustration]
THE QUEEN HORNET
(_Vespula maculata_, Linn.)
The summer was over but the cold weather had scarcely begun when I found
this creature under a rotten log in the pasture. The paper nest over the
front door was empty and rapidly falling to pieces, but even so, it was
hard to believe that the active, dangerous creatures we had watched for so
many weeks had suddenly disappeared, and that, of the whole busy colony,
only a few females were left.
There is something fascinating in the picture of the young queen hornet,
after mating is over and all her relatives are dead, crawling away beneath
some log and passing there the long cold winter. Then, when spring has
come, she emerges from her sleep, the only survivor of her race, and
builds, unaided even by her mate, the beginning of a nest just large
enough to hold her first-laid eggs. From these hatch out the grubs, which
later, after days of feeding, emerge as workers, undeveloped females, and
help build up around her a colony of hundreds of busy hornets.
The death of the wasp and hornet workers does not seem to be a matter of
cold alone, for, in the regions of perpetual summer, the workers of many
species live short lives. They feel the cold, of course, as all our
insects do, and inside the nest, on the shelves formed by the flat tops of
the combs where the larvæ live, they find dry roosting places at night.
The heat of their own bodies materially raises the temperature inside the
nest.
Though many people think them just alike, the bees and wasps (the hornet
is a kind of wasp) are very different creatures. The wasps have trim,
slender forms with a few scattered hairs upon their bodies, whereas the
bees are generally hairy and short bodied. They both build combs, but the
wasps make theirs of paper wetted with saliva, while the bees build theirs
of wax secreted from their bodies. The wasps depend upon fresh food
gathered in the day's hunt through the air, whereas the bees store up
their food in empty cells. The wasps' nests are the wigwams of a season,
the bees' hives the more permanent abodes of a higher type of social
beings.
[Illustration]
THE YELLOW JACKET
(_Vespa carolina_, Dru.)
Who has not wished that these brown and yellow striped creatures would
build their nests where people could see them and be warned to stay away,
instead of underneath the ground as they do now.
They hunt in flocks, and it is no wonder that with the sides of their
heads all eyes and with three other eyes on the top of the head they
should quickly find anyone who treads on their underground nests.
[Illustration]
ONE OF THE SOCIAL WASPS
(_Polistes metrica_, Say)
No insect's nest is better known than the small, hanging, paper comb of
this social wasp. You find it under eaves and suspended from the ceiling
of the porch and from the rafters of the barn. Then, as the cold days of
autumn come and the workers and males of the colony die off, their
hibernating queens seek shelter from the cold in our houses.
In the spring these queens start out to build a few small, paper cells
with finely chewed up fibers of wood wet with sticky saliva. In these they
rear up workers to help add new cells and gather food for a new family,
and before the summer season has rolled by, the few small paper cells have
grown to several scores.
If you have the hardihood to stand quite close to one of these nests you
will see the grubs with hungry-looking mouths, wiggling and stretching out
their necks, each in a cell quite open to the air, waiting to be fed by
its sister or the queen. As to which will come forth from these white
grubs as queens, which as males, and which are doomed to be but
workers--undeveloped females--nobody can foretell, but certain it is that
there will be all three of these forms represented.
[Illustration]
A MUD DAUBER WASP
(_Sceliphron cementarium_, Klug)
Think of all the marvelous mechanism and chemistry required in order that
a wasp may feed its young upon fresh meat!
The solitary wasps have stings whose venom is much less powerful than that
of the bees. Fabre declares that his experiments convince him that the
reason may lie in the fact that for paralyzing its prey the wasp needs
only a weak poison whereas when the bee stings it does so in self-defense
and it stings to kill.
The busy mud dauber females build their nests of mud brought from the
nearest puddle and in each carefully made cell lay an egg and around it
pack the paralyzed insects on which the voracious little grubs begin to
feed as soon as they hatch out.
By the time the young grubs have eaten up the food that has been so
thoughtfully supplied by their parents and have changed from grub to pupa
and emerged as flying, stinging wasps, their parents are dead and gone.
Imagine, if you can, a civilization in which the mothers slave for
offspring which they never see, and the children grow up with no
education, yet possessed of all the knowledge that their parents had. As
Sharpe remarks, the solitary wasps are among the most instinctive
creatures of the animal kingdom.
[Illustration]
THE FOOD OF A MUD DAUBER'S BABY
This little white spider I found in the nest of a mud dauber wasp.
How long this white spider would have lived its paralyzed existence I do
not know. Fabre has watched insects so paralyzed for six weeks, and this
one was on my table for several weeks in June without moving and without
showing any sign of decay.
We are accustomed to think of the wonders of cold storage as a result of
this age of invention, and to look upon its achievement as the
accomplishment of the human brain. The mud dauber, in common with most of
the so-called solitary wasps, possesses the means of paralyzing the nerve
centers of its prey and thus preserving it alive for weeks in the nests of
the baby wasps. With the most amazing aim it darts its poison sting
between the joints in the armor plate of its victim and touches with a
drop of poison one of the nerve ganglia which lies on the abdominal side
of most insects.
Fabre has shown that the same result can be produced by a needle and a
drop of ammonia, and insects paralyzed in this way hang, as it were,
between life and death for weeks or months. If too heavy a dose is given
the insect dies in a few hours and putrifies in a few days, and if given
too light an application it soon recovers. Different insects require
different amounts of the poison to paralyze them and the solitary wasps
make mistakes just as man would do. According to Fabre these insects have
also discovered that in certain species of their prey the nerve ganglia
are grouped close together and can be easily reached with the poison while
in others the ganglia are separated, and each ganglion must be touched.
It is a weird thought that for thousands of centuries these creatures have
had a perfectly satisfactory way of preserving and storing fresh food
while man still kills his animal food and is now quarreling as to how it
should be stored and whether if frozen for months it is really good to
eat.
[Illustration]
THE FIG INSECT ON WHICH DEPENDS A GREAT PLANT INDUSTRY
(_Blastophaga grossorum_, Grav.)
Into every dried Smyrna fig that you eat a queer little beast like this
has crawled; unless she does so, no seeds will form, for the inside of a
young fig is filled with flowers waiting to be dusted with pollen and it
cannot develop until this is done. This tiny, female wasp, so small you
can scarcely see her with the naked eye, is the pollen duster of this
miniature flower garden.
The Blastophaga hatches out from a tiny egg which her mother lays in a
special flower or gall in the flower cavity of a wild, inedible Caprifig
that came originally from the islands off the Syrian coast. Her mate, an
ugly little thing with no wings at all, hatches out before she does and
mates with her even before she comes out of her tiny cocoon. After
wandering about among the stamens in the cavity in the Caprifig until her
back and sides are covered with pollen, she finds her way out through the
hole in the end of the ripening wild fig and flies away in search of
another young and ripening fig in whose gall flowers instinct impels her
to lay her eggs.
The larger, juicier Smyrna fig attracts her, and she crawls inside,
searching for gall flowers there. But the Smyrna fig has no special places
for her eggs and, after wandering around over the flowers in the floral
cavity she wanders out again, or dies. But in this scramble over the
sticky stigmas of the Smyrna fig flowers, she irritates them and leaves
upon them the pollen which she brought with her from the wild fig. This is
what causes the young seeds of the Smyrna fig to grow and the fig itself
to swell and become the honey-sweet fruit which we eat.
Without the visits of this tiny wasp the figs either fall off on the
ground when young, or else form insipid tasteless fruits. So it might be
said that the great fig industry of Smyrna hangs on the blundering
instinct of this little creature.
Some enterprising Californians brought over and planted orchards of the
Smyrna fig and could not understand why they did not bear. Then they
brought in the wild Caprifig from Smyrna and planted it side by side with
the Smyrna figs, but still with no result. Finally the experts of the
Department of Agriculture were called in and solved the problem by
introducing the insect, which had been left behind.
This little creature, in the picture, crawled out in my laboratory from a
Caprifig which Doctor Rixford, the fig expert of California, sent me,
requesting that I photograph his pets.
[Illustration]
THE COW KILLER OR VELVET ANT--A WINGLESS WASP
(_Mutilla simillima_, Sm.)
Can you imagine an insect daring enough to brave the stings of the
thousands of workers in a bee's nest? This wingless, solitary female ant
lives habitually in their nests and eats the food they have so busily
gathered, an unbidden and probably a most unwelcome guest. Powerful jaws,
formidable sting, an armor-plated shell to protect her from the stings of
the bees and wasps in whose nests she lives, seem to fit her for the
strange life she leads.
If you should find her mate he would doubtless be on the wing, for unlike
all others of the order, it is the male alone which flies. So different
from their mates do some of these male cow killers look that they have
often been mistaken for quite different species.
It is supposed that the female lays her eggs inside a bumble-bee grub and
in a few days' time they hatch and eat the babies up, from the inside
outwards. Then they hatch again, so to speak, as full-fledged cow killers
and feast upon the honey of their hosts.
[Illustration]
THE WORKER BUMBLE-BEE
(_Bombus vagans_, Sm.)
Everybody has a friendly feeling for the bumble-bee, that clumsy rover of
the clover field whose buzzing seems part of the still summer air. She is
the real worker of the hive, an undeveloped female, her hind legs laden
with a mass of pollen from the flowers she has visited, and her honey sac
filled with nectar.
As every boy who has hunted her nest will know, the bumble-bee lives in
burrows under ground.
The cells that she makes are of wax, secreted from special plates which
lie arranged in rows beneath her hairy body. Each cell is like a little
jar, standing on end, quite different from the cells in a honey bee's
comb. In some of these the eggs are laid and the baby bees hatch out,
while others are filled up with nectar.
While the bee is gathering pollen with her legs, she is also gathering
nectar with her tongue and storing it in a special honey stomach from
which she later regurgitates it into the honey cells in her nest.
The nectar, when it is gathered, is thin, like the sap of the maple tree,
and, like it, must be condensed. Part of the water seems to be taken out
in the honey stomach, and part evaporates from the honey cell.
It will, perhaps, be a satisfaction to those who hate getting up early to
know that there is a well-founded rumor that some bumble-bees have a
trumpeter who, somewhere between three and four o'clock in the morning,
wakes up the sleepy hive.
[Illustration]
THE POLLEN PLATES OF THE BUMBLE-BEE
(_Bombus americanorum_, Fab.)
If you will watch a bumble-bee closely as she crawls over the stamens of a
wild rose, perhaps you can see that, although she covers the whole under
part of her body with pollen, yet she scrapes off all she can with her
feet and packs it in a yellow mass on the smooth, hairless segments of her
large hind legs, the pollen plates as they are called. To make the pollen
stick on these smooth plates and hang together during the flight to the
nest, it is claimed by Muller that the bee mixes nectar with the pollen
grains. The kind of pollen that she gathers is, however, not generally the
dusty kind, like the pollen of the pines or grasses, but the sticky kind
that comes from insect-fertilized flowers. When the bumble-bee reaches her
nest, she scrapes the pollen from the pollen basket and with it feeds the
young, for pollen is the solid food of baby bees.
There is one strange thing about these smooth pollen plate legs which,
from our human, individualistic point of view, is hard to understand. It
is only the workers, the undeveloped females, which have them; the legs of
the males and of the queens are hairy and are not at all adapted for
pollen gathering. Thus, since workers bear no children, we see a race of
parents transmitting to certain of their offspring characters which
neither they nor any of their ancestors have ever possessed.
[Illustration]
THE BUMBLE-BEE AT WORK
This photograph shows the great hybridizer at work.
She is on one of the single roses, her hairy body spread over the stamens
which, with their yellow anthers, look like a circular bed of tulips. In
the middle of the circle, where her right foot rests, is the stigma.
If you will sometime take a hand lens and watch a bee at work (and if you
don't get too close she will pay no attention to you), you will notice the
clumsy way she crawls about, knocking the pollen off the stamens and
getting her body covered with the yellow dust. As you watch, any feeling
of there being some mystery about cross fertilization will be dispelled.
How this same bumble-bee could crawl across another rose blossom _without_
leaving a trail of yellow pollen on its stigma would be the mystery!
Since the earliest days of the world of plants and insects, the bumble-bee
and her ancestors have been at work mixing the pollen on hundreds of
different plants and playing, doubtless, a perfectly gigantic role in the
creation of the flowering plants which now cover vast areas of the globe.
It is perhaps an idle speculation, but it would be interesting to know how
many plants would become extinct were some disease or parasite to
exterminate the bees.
[Illustration]
THE TELLTALE MILKWEED POLLEN
(_Bombus sp._)
Although this bumble-bee was caught in flight across my meadow, her
photograph shows beyond the shadow of a doubt that she had been a recent
visitor to the blossom of some milkweed, for, projecting from her right
hind leg and plainly visible, are the pollen masses of the milkweed
flower. They look like little paddles and hang in pairs, although this you
cannot see in the picture.
We know that flowers depend upon the bees to fertilize them, but somehow I
do not think we grasp the completeness of this dependence, nor realize how
many flowers there are which, unless they have their own pet insect
visitors, would soon become extinct.
The milkweed lures its visitor with little cups of nectar, and beside each
cup it sets a trap which is as carefully worked out as the steel traps
which the modern trappers use. Across the top of a little slit, wide below
and narrow above, lie the small ends of the paddles or pollen masses,
firmly joined together. As the bee alights to sup the nectar, her foot
slips into this crack, and in trying to extricate it she pulls up the pair
of paddles which fasten themselves onto a hair of her leg like a
clothespin on a line. In drying, the paddles clap together in such a way
that by the time another milkweed flower is visited they can slip with the
leg right into the little slit and are broken off and left there as the
bee again pulls out her leg. Once inside, these pollen grains throw out a
score or more of tiny, rootlike tubes which grow into the lining of the
slit and carry to the ovary below the fertilizing germ plasm which makes
the seed develop.
The bumble-bee, of course, is strong enough to slip into these traps and
pull her legs out as a routine thing, but many small moths and butterflies
are not, and these get caught and die upon the blossoms.
[Illustration]
THE POOR MALE BUMBLE-BEE
(_Bombus americanorum_, Fab.)
It was late in October before I noticed, flying low here and there across
the clover tops, large bumble-bees, which seemed to be more covered with
golden hairs than those which I had watched throughout the summer time. At
first I thought them queens, but as their number multiplied I felt I must
be mistaken, and one of my insect-knowing friends explained that they were
only males, and that with the approaching days of winter they were all
doomed to death. Already, he pointed out, their wings were battered and
frayed from flying against the autumn winds.
The importance of the males! Could there be a weaker argument against
woman's suffrage than the one which has been brought forward that
throughout nature the duty and the right of protection rests with the
male? Perhaps the drones do fight among themselves; but, as in most other
fighting of the males, it is not to protect the nest or young from
perishing, but merely to determine which one of them shall win the queen's
attention. The males are stingless.
In this world of the clover field all the work of the society is done by
the queen herself, or by the workers, which are infertile females.
Apparently few males are wanted in the colony until late in the season,
when, for a brief period, they are tolerated in considerable numbers as
the necessary courtiers who accompany the young queens of late summer in
their marriage flight. This takes place before the winter comes to kill
all but a few fortunate queens, which find safe shelter in some crevice in
the rocks or underneath some old, decaying log.
[Illustration]
SOLITARY LEAF-CUTTING BEE
(_Megachile brevis_, Say)
Unlike the social honey and bumble-bees, this bee leads a solitary life.
With her strong, saw-like jaws, the female makes her burrow in soft wood
and lines it with bits of leaf which she has cut from some plant. When the
leaves of plants in the garden have large round holes in them, in nine
cases out of ten you may be sure that they have been cut by some solitary
bee.
When the burrow is complete she makes a ball of pollen and nectar, puts it
in the bottom of the burrow, lays an egg upon it, and, with a wad of
leaves, securely shuts it in; over this she lays down another food ball
with its corresponding egg, and so on, until the burrow is full.
[Illustration]
THE STINGER OF THE LEAF-CUTTING BEE
(_Megachile brevis_, Say)
The sting or "stinger" of a bee is indeed a most wonderful piece of
mechanism. At the base, inside the body of the bee, lie bars or levers,
operated by muscles, which push the darts out and draw them in. The poison
sac lies just behind this mechanism and pours the poison into a set of
cup-like valves, from which it escapes into the wound along longitudinal
grooves in the sting like grease along the piston of an engine.
The sting itself is not, then, hollow, like the spider's poison fang, but
is a poisoned stiletto as long as the bee's foreleg which she can thrust
in and out with incredible rapidity, and which, as everyone knows, can
inflict a painful wound on creatures millions of times her size.
[Illustration]
A COMMON RED ANT
(_Formica sp._)
Ants are undoubtedly the highest, structurally and mechanically, of all
insects, and at the same time the most efficient. Their social
organization has been the admiration of human beings from the earliest
times, because the interest of the individual is merged so completely into
that of the colony; but, as Wheeler remarks, their organization must
strike the individualist with horror.
It is an organization of females, too. The workers are females, the
soldiers are females, the nurses are females, and there is one queen
mother for them all, who lays all the eggs of the colony. Where are the
males, those representatives of society, those voters of our human
colonies? They do not exist as such, for the males of ant colonies are but
mates for the young queens. Together with them they leave the nest on
their marriage day and together make the marriage flight, but as soon as
this is over they die, and the colony gets on easily without them.
To man, who is the most rapidly evolving organism on the earth today, it
is a strange thought that the most highly developed insect which the world
has produced, and which has not changed materially since the Tertiary
epoch, has relegated the males to the short-lived function of
reproduction, leaving him no work to perform and getting rid of him as
quickly as possible. Why did the ants, with their marvelous instincts,
fail to conquer the world? Why have they stood still for thousands of
years after they had perfected their social organization? Did they go as
far as evolution could go when it leaves the male out of account? It is
perhaps a comfort to think that, after all, they have failed and the
man-guided organization of human beings has surpassed them in its
development!
[Illustration]
A BLACK ANT
It is strange to think that just because the sunlight which poured upon
this little creature's shiny body was reflected back against a
photographic plate, its rays being made to diverge widely in so doing, we
can get an image of this tiny ant as large as though it were a mouse.
What a world this would be to us had we microscopic vision! A thousand
times as many beasts to look at, a thousand times as many things to see
and understand!
[Illustration]
ANT GATHERING NECTAR FROM LEAF NECTARIES OF THE CHINESE WOOD-OIL TREE
A year ago I planted in my garden in Maryland three young wood-oil trees
from the Yangtse valley of China, broad-leaved trees something like the
catalpa. Just where the leaf stem joined the leaf blade there were two
curious, dark red, oval glands. The use of these I did not understand
until one morning I discovered a big black ant on each leaf, and each ant
was stationed at the base of its leaf near these glands and evidently was
lapping up from them small drops of nectar which kept oozing out from the
center of each gland.
These rapidly-walking little creatures, which spend their time roaming
everywhere, had discovered the use of these nectar glands although they
were on the leaves of a plant which they had never seen before.
Whenever I touched a leaf the ant upon it ran about as if to frighten an
intruder away, and I could not help but wonder if in China, where the
wood-oil tree is at home, there might not be some stinging ant which takes
upon itself to protect the foliage from the attacks of caterpillars, and
gets, in payment for its labor, the nectar from these glands. The tropics
are full of such agreements between the plants and the ants, and very
effective ones they are, too.
The photograph shows a black ant with antennæ extended, reaching over one
of these big glands for the drop of nectar which glistens just below its
head. On the other gland, just back of the ant's left antenna, a second
drop of nectar can be seen.
First one and then the other of these nectaries is licked clean by the
ant, and so well was the work done that throughout the summer it was only
when I visited the leaves in early morning, before the ants were out, that
I could find the beads of nectar in their places in slight depressions in
the glands.
[Illustration]
THE ICHNEUMON FLY: ENEMY OF THE SPIDER
(_Crypturopsis sp._)
It would seem as though the spider ought to be able to protect itself from
such a beautiful creature as this, but she is said to be one of the
spider's worst enemies. With the long ovipositors which may be seen in the
photograph and might almost be mistaken for her sting, she lays her eggs
inside those of the spider and the larvæ hatching from them eat up the
spider's eggs. It is, so to say, an insect cuckoo, or worse than that, for
the bird cuckoo only crowds the real children out of the nest, whereas the
ichneumon fly devours them.
From man's point of view, however, many of the tribe to which this
so-called fly belongs are his good friends, for they hold in check some of
the pests which molest the plants he lives upon.