Chapter II: The Insect World (2)

It is one of the hardest things in all the world to understand how balanced is this scale of foe and friend. One year there is a wiping out of our insect friends through frost or floods or microscopic disease, and, freed thus from the check which kept their numbers down, the foes to our plants can multiply to such an extent that nothing we can do will save our crops from total failure. Next year, perhaps, the parasitic beetle, finding such a wealth of food to live upon, increases and holds well in check the pest which last year ate up all our plants. Each wave of insect pests could be explained, no doubt, if all the facts were known, and nowadays no one who knows what modern agriculture means will fail to reckon on the risks from losses caused by these pests.

THE CLOVER LEAF WEEVIL

(_Phytonomus punctatus_, Fab.)

Could anyone suspect this modest antediluvian creature coming toward you out of the gloom, hanging his head, as it were, of any designs against anyone? He has them, however, and if you will examine your clover leaves in June you will find them scalloped with irregular patches eaten out of them. It would be easy for him to prove an alibi, since it is his other self, his larval existence, which does it and does it at night, too, coming up out of the base of the clover plant where it hides during the daytime. Occasionally in August he can himself be seen feeding on the clover leaves. In his two existences he manages to do a good deal of damage to the clover fields of the farmer, necessitating the plowing up of old fields when he becomes too numerous.

But let us look at the company he keeps. He is in the same class with the alfalfa weevil which came over from central Asia recently and spread through the alfalfa fields of Utah, threatened the alfalfa growers with ruin and set the Entomological Bureau of the Government out on the trail of some parasite, some enemy of his which they were sure must have held him in check in his native land. If you could have heard the conferences which were held and the drastic measures relating to traffic which were proposed you would realize that it is no child's play to fight the Asiatic relative of this modest-looking creature.

But it has in this country worse relatives even than the alfalfa weevil. It is related to the cotton boll weevil, which has brought thousands of families in the South to the point of starvation and drawn millions of dollars from the federal treasury of the country in an effort to fight it and lessen its ravages throughout the cotton belt of the Southern states. Thousands of lectures are being given to tell the farmers what its habits are and how it can be prevented.

It has other more distant relatives which live in the forest trees and make wonderful burrows which look like hieroglyphics. As that remarkable entomologist, Hubbard, discovered, they are cultivators of microscopic mushrooms as wonderful as those of the mushroom nests of the atta ants or the termites of the tropics. Incidentally, and this is the important point, they kill the trees, fires start in the dead trees, and it is estimated roughly by Dr. Hopkins, the Forest Entomologist, that they destroy over a hundred million dollars' worth of timber annually or, at least, are one of the principal causes of this gigantic loss.

THE SPOTTED VINE CHAFER IN FLIGHT

(_Pelidnota punctata_, Linn.)

How often one sees lame butterflies limping along in their flight, because their wings have been injured by the rose bushes or by striking against the pine needles or have been nipped by some hungry bird. The beetles, when they alight, carefully fold up each delicate wing, close down over them polished covers as hard almost as steel and fitting as closely as the engine covers of an automobile. Whether these wing covers act as aeroplanes or as rudders for the beetles when in flight is as yet unknown. There are strange, almost microscopic, markings over the surface of these wing covers and in some species there are glands inside them which secrete a fluid which reaches the surface through minute pores, but the use of this fluid we are still unable to discover.

It seems likely that the discovery, if we may so term it, of these wing-protecting shells, has been of tremendous advantage to the class of organisms where it first appeared. At any rate, among the insects the order of beetles (Coleoptera) is the predominating one of this epoch.

When one thinks that man has just begun to fly, whereas the beetles flew perhaps a hundred million years or more ago, these wings and their most perfect chitinized wing covers are deserving of our wonder and of our admiration, too.

This light, yellowish brown and black spotted beetle prefers the leaves of the grape vine to those of any other plant, and in its grub life it burrows in rotten wood, especially in decaying roots of apple, pear and hickory trees.

ONE OF THE BLISTER OR CANTHARIDES BEETLES

(_Epicanta marginata_, Fab.)

I can never look at this beetle without a feeling of emotion, for in a desperate struggle to escape from the fate predestined by a bald-headed ancestry, I once submitted to the treatment of a noted hair specialist and allowed him to apply to my scalp the acrid oil of the blister beetle. And the melancholy part is that it did no good.

Fabre has described how the female European blister beetle lays a thousand or two eggs in the ground in close proximity to the nest of the solitary bee whose eggs form the only food of the blister beetle larva. From the beetles' eggs hatch out strong-jawed, six-legged spiny larvæ called triangulins. Although born close to the nests of the bees, which in this case are in the ground, these triangulins do not enter the nests, but attempt to attach themselves to any hairy object which may come near, much as burrs attach themselves to the wool of sheep.

A certain number of them by merest chance, apparently, succeed in getting onto the bodies of the bees and are carried by them to their nests. As the male bees, in this particular species, appear a month before the female, it seems probable, Fabre thinks, that the vast majority of triangulins attach themselves at first to the males and later, when a chance occurs, discovering their mistake, transfer themselves onto the females and so get carried to the underground cells, and are present when the mother bee fills the cell with honey and then lays an egg which floats around on top.

There is something ghastly in the picture of the mother bee laying her single egg, with the blister beetle larva on her back waiting till the last moment in order to slip unexpectedly from her body to the egg, on which it floats in the honey as on a raft. When the unsuspecting bee has closed in her unborn child, the hideous monster which is perched on top of it eats it up. This takes eight days, and when it has eaten up its raft, the triangulin moults and becomes, as it were, an aquatic creature with breathing pores so placed that it can float on the honey, and with a stomach so changed that it can be nourished by it. In about eight more days the honey is consumed and the final moult takes place.

A HIPPOPOTAMUS AMONG THE INSECTS

(_Prionus sp._)

Why beetles as large as elephants never came into existence on this planet, or have they developed on some other of the countless worlds of space, are questions too hard for us to answer.

This wonderfully protected creature with long horn-like antennæ and hippopotamus-like jaws is a relative of the largest of the beetles, those which live in the great forests along the Amazon or in the tropical jungles of the Fijian Islands, and whose grubs are good to eat. Some years ago, in a clearing in a New Zealand forest, a Maori dug out several handfuls of the white wriggling creatures for me and a settler's wife fried them with butter over the fire in her kitchen stove, and I can testify that they were as crisp and delicate as fried oysters.

Like the other giant creatures of the forest, these Prionids, as they are called, are growing rarer with the destruction of the forest trees on which they live, and some day their skeletons in museum cases may be all that remain of them.

These long-horned wood borers do not themselves bore into the wood; how could they with their long antennæ? It is their other selves, their grubs, that live deep in the solid heart wood of some oak or hickory tree. There is something strange in their solitary hermit-cell life. Think of living for two years or more in a narrow hole which shuts you in on all sides and having for a steady diet the walls of your cell to feed upon. Prisoners have burrowed under prison stockades to escape, but these larvæ deliberately leave the outer, softer sapwood in which they hatch, and start for the interior of the trunk, packing behind them with sawdust and excrement the tunnel which they eat out.

The fact that the grubs of some species of these Prionids choose to live in the roots and trunks of trees which we choose to cultivate makes them our enemies, and every good orchardist knows that the only way to stop them is to dig them out or stab them with a wire run through them in their burrows.

This fellow bit savagely at a pencil, and when he finally caught hold, I lifted him up as one does a bull dog, and he hung there almost as long.

ONE OF THE LONGICORN BEETLES

(_Orthosoma brunneum_, Forst.)

At first glance this longhorn might pass for a Prionus, but its antennæ are very different and the shape of its broad collar or prothorax is not the same. To a trained eye they could never be confused, which cannot be said of all beetles! In fact there is perhaps no group of living organisms which scientific men have more difficulty in classifying than the beetles, unless it be the lichens on the stones and trees. Their differences are so minute and their grub lives so obscure that they have sometimes to be bred in order to determine their relationships.

AN AMERICAN SCARAB

(_Copris carolina_, Linn.)

I cannot help wondering what one of the priests of ancient Egypt would think of this picture of a New World relative of his sacred scarab. To me there has always been something strangely beautiful in the veneration which the great Egyptian race has shown for thousands of years towards the humble, industrious beetle which spends its life in the droppings from Egyptian cattle.

Go to Gizeh, and look at the images of the scarab beetle carved from the rarest stories the lapidary could find, mounted in the loveliest gold settings he could fashion, and reflect that the ladies of the court wore these dung beetles around their necks and were buried with them on.

Was this veneration of the scarab as old, almost, as the race, and did it come with the race into its civilization, or did it arise as the whim of some great Pharaoh?

It is said that somewhere with this veneration there was included a symbolism. The living scarab is a tumble bug, the female makes a ball of dung much larger than herself and either with her shovel pointed nose, or else standing on her head with her hind legs on the ball, she either pushes or pulls the ball along until she finds some suitable place in which to dig a hole and bury this ball so that later she may consume it at her ease. It has been suggested that some Egyptian astronomer, watching the rolling ball, may have suggested an analogy with the movement of the heavenly bodies--with the traveling of the moon around the earth. For we must not forget that in those days the wonder of the heavens was fresh and new and the idea of world-balls of matter was a subject of intense intellectual excitement.

But there was yet another reason for the veneration of the Egyptians. The fact that these beetles suddenly disappeared into the ground and that later they appeared again was taken as proof of a future life.

It seems to me that we can take a lesson from the ancient Egyptians and see in things as insignificant as the beetles of manure the greatness of the world of change and really feel the wonder of it all.

It is a pity, but I have to admit that this American species is not a "tumble bug," but contents herself with digging holes, filling them with manure and laying her eggs on it, instead of rolling a well-made ball to some special place as her Egyptian cousin does.

The mother scarab, unlike every other beetle, lives to see her children grow up, indeed she produces two families of little scarabs.

THE TWELVE-SPOTTED CUCUMBER BEETLE

(_Diabrotica duodecim punctata_, Oliv.)

There are few of our insect enemies which do their destructive work more rapidly than do the cucumber beetles. Every child in the South who has left his cucumber hills unscreened knows this, for he has found them some morning literally eaten up over night by the spotted or striped yellow-green cucumber beetles.

The puzzle is, where do they come from so suddenly? It is as though they were waiting for cucumbers to come up, and this is pretty nearly true, for the adults have wintered in the leaves and rubbish of the garden and are all ready to concentrate on the plantlets in the spring.

Unlike so many pests, which are content to trouble us only during a part of their existence, this twelve-spotted cucumber beetle is our enemy all its life long, for it spends its larval life eating the roots of corn and other field crops.

It is a wide-spread pest, with many relatives quite as bad as it is, and not only does it eat up the young and defenseless cucumbers and the roots of the corn, but it is the carrier of a germ infection of a serious nature to the cucumber. My friend, Dr. Erwin F. Smith, informs me that its kind has infested large areas in the South with this disease and dashed the hopes of thousands of boys who, instead of feasting on the melons they have planted with such care, must stand helplessly by and watch the leaves and flowers wilt and the vines decay. It must be remembered that this is a winged carrier of disease and anyone who still fails to understand the speed of travel of an epidemic had better watch the cucumber beetles busy spreading this destructive germ disease. A single beetle feeding on a diseased leaf can carry on its jaws enough germs to infect every melon or cucumber plant in a neighboring field, and that, too, in a single day.

ONE OF THE SAWYERS

(_Monohammus titilator_, Fab.)

While standing on a street corner waiting for a street-car one day last summer my attention was attracted to this beautiful squirrel-gray creature at my feet. It was so evidently ill that, as I picked it up, I began to examine it to find out what was the matter. Clustered on its neck, out of reach of its feet or jaws were whitish bodies which evidently did not belong to its external skeleton but were probably the eggs of what I took to be some parasite whose growth within the body of the beast had brought about its pitiable condition. These are just visible between the creature's "horns" in the photograph. It was, in other words, a sick insect.

It is because biologists see these parasites so plainly all down through the scale of living things that they are so sceptical of accepting any other cause of human disease until all possibility has been excluded of its being caused by some parasite or other, too small to be seen even by using the best microscopes.

My sympathy for this long-horned beetle would be keener did I not read that its larval self is spent inside the wood of the pines and firs of our forests, doing great damage to them.

When one is puzzled to know why any living thing should be burdened by such antler-like antennæ, let him remember the peacock's tail and the bird of paradise's plumage and be content to know that the laws of evolution are not yet fully known, and that, given time and growth, almost any form can be evolved.

TWO-WINGED INSECTS

(_Diptera_)

Years ago in Berlin, my German landlady called me in as an expert to decide a controversy between her children and herself as to whether a frog had four legs or six. It seemed strange to me then that a grown-up woman should not know the number of a frog's legs. Yet there will be many who read these pages who do not know how many wings a fly has. And flies are much more important than frogs.

In fact the mosquito and the house fly, both included in the order of the flies, probably cause more deaths and are more dangerous to human life than any other creatures in the world.

These portraits are of a few only of the vast myriads of forms of two-winged insects which haunt the world. Were I to photograph just one individual of each different species which inhabit the globe, I would have to spend a lifetime doing it, and when it was finished it would make five hundred volumes about the size of this one.

There should never be the slightest difficulty in telling a fly from other insects for there are no other two-winged forms.

Although the flies are sucking insects, their beaks lap up liquid food and are not at all like the beaks of the bugs. In the great majority of flies, the beaks resemble a trunk with curious fleshy folds or lips. It is true some species, like the mosquito, have long, sharp-pointed stylets which, working up and down, puncture the skin of plants and animals.

The larval forms of many flies are maggots, those squirming, often almost headless creatures that abound in rotting carcasses or decaying matter of all kinds, and this is one of the reasons why less is known about the flies than about some others of the insect world which have selected less revolting birthplaces.

Of course, in such a gigantic family no general rules apply, and still, a maggot, whether in an orange or a dead horse, is most likely to be the larva of a diptera or two-winged insect.

THE CRANE FLY

(_Limnobia sp._)

Every lover of the autumn woods must have noticed on some still October day, in the little clearings in the woods, these awkward, long-legged flies which, frightened by the approach of a human being, gather their ungainly hind legs together behind and their forelegs in front of them and slowly and laboriously flutter upward into the sunlight. They are well-named, these creatures, "the crane flies," for their legs are as long and apparently much more useless than those of the crane. In fact some entomologists have expressed themselves as wondering why they have such legs at all for they are so fragile that they break at the slightest touch.

They belong to a family with a thousand species in it and perhaps the most peculiar thing about them is that some forms of the family live and fly about when there is snow on the ground. This is a very rare exception in the insect world.

AN INSECT HAWK: ONE OF THE ROBBER FLIES

(_Erax æstuans_, Linn.)

Her strong, spiny legs, her powerful body filled with strong wing muscles, and her sharp beak, make this robber fly one of the most dreaded enemies of the other winged insects for, like the hawk among the birds, she pounces on them in their flight and tears them to pieces with her beak, sucking the blood from them as she carries them in the air. A single one of these insect hawks, or robber flies, as they are called, has been known to catch and devour as many as eight moths in twenty minutes.

These robber flies are fearless creatures, for they attack and kill bumble bees and wasps and even, it is said, that monster demon, the dragon-fly. Tiger beetles, too, are said to fall a prey to this insect hawk.

Its other or larval self is also predaceous, boring into beetle larvæ in the ground.

A ROBBER FLY

(_Dasyllis grossa_, Fab.)

When I learned that this powerfully winged, hairy fly tears beetles' wings from off their backs with that wedge-shaped beak of hers, and sucks the blood of bees and wasps, it gave me a different idea of the great fly family, which hitherto I had thought was made up of defenseless creatures like the house fly.

Of all the insects we have photographed, few have seemed to be more thoroughly fearless or more ugly than the robber flies. I have never seen one capture and devour a creature larger than itself, but it must be as thrilling an adventure as to see a dragon-fly devour a gnat, or a spider pounce upon the prey entangled in its net.

ANOTHER VIEW OF THE ROBBER FLY

(_Dasyllis grossa_, Fab.)

At first it looked as though this creature had two heads, one at each end of its body, but the great facet eyes, of which only one can be seen in the photograph, make it clear which is the head and which the egg-laying end of this strange, fearless robber of the air.

Just why it is called a robber fly when it really doesn't rob at all, but kills, is a mystery to me.

ONE OF THE LARGE ROBBER FLIES

(_Mallophora sp._)

This robber fly is not so quick nor so savage as many of its family. It waits for some slow moving insect to come along then pounces upon it.

It probably breeds in decaying wood, although this is not certainly known, and it is very difficult to breed them artificially.

To the economic entomologist the ability to breed these monsters in captivity is one of the most important factors in studying out their life histories, as they are called, their various stages, the plants they feed on, their habits of moulting, of breeding and of feeding their young.

ONE OF THE WORST OF THE ROBBER FLIES

(_Deromyia_)

This creature is very savage and pounces upon even large sized insects, paralyzing them instantly by a sting of its poisoned beak.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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?

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.

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.

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.

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.

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.

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.

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.

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.