Its powerful beak is made up, as are the beaks of all the great order of sucking insects, of four hairlike bodies, four fine, flexible, closely connected rods enclosed in a narrow groove and sharp enough to puncture the skin of a succulent young plant. Not only are these hairlike rods as sharp as needles, but the outer pair are usually barbed so that, once introduced, a hold is easily maintained.

Under the throat is an organ of the nature of a force pump which injects an irritating fluid into the plant. It is supposed that this gives rise to an irritation or congestion of the plant tissue, and thus keeps up a supply of liquid food for the bug at the point operated upon, which, rising by capillary attraction along the grooved rods, finds its way into the stomach of the insect.

That these leaf-sucking insects inject a poison is shown by the way in which the punctured leaves curl up, turn brown and die.

THE BEETLES

(_Coleoptera_)

Beetles are distinguished from the other orders of flying creatures by having the first pair of wings changed into sh.e.l.ls under which the other pair can be safely folded and laid away. You can usually recognize them when they spread their wings to fly, for they have to raise their wing covers in order to do so. Also they generally have prominent jaws, as they are biting creatures and do not suck the juices of plants and animals as the bugs do.

Beetles are almost everywhere. You cannot turn over a stone or break down a stump or roll over a log without disturbing some of them, and yet perhaps less is known about the lives of beetles than about those of any other of the great orders of insects.

They lead two lives, distinct as two lives can be: one in the form of a grub, the other as a full-grown beetle. To make the transformation, they burrow into the ground or into the wood of trees and but rarely make for themselves silken coc.o.o.ns such as the b.u.t.terfly larvae spin.

They do not lead so aerial an existence as some other orders, but, nevertheless, they are today, perhaps because of their closely fitting outer sh.e.l.ls, the predominant order of insects of the present epoch and already there are known the bewildering number of 150,000 species. In North America alone (Mexico excepted) 12,000 species have been described and these have been grouped into eighty families and 2,000 genera. The general public is beginning to realize that not everyone can be an entomologist, and that the quality of brains and training required before one can travel safely among this maze of forms and distinguish between the friends and foes of our agriculture is a quality of the greatest value to mankind.

So far as man is concerned, this gigantic cla.s.s of creatures is among the most destructive with which we divide life on this planet, and though there are beetle friends which help us by preying on other beetles and by making humus out of leaves and twigs, and by feeding millions of our song birds, yet, as a whole, they represent a restless, armored mult.i.tude which perhaps we should be just as well without.

[Ill.u.s.tration]

THE JUNE BEETLE

(_Allorhina nitida_, Linn.)

In looking at these two strange beings (this picture and the next), we cannot feel confident that science has gone very far in giving us the reasons for the things we see. They seem no more alike than fish and tortoise or bird and quadruped and yet, before our very eyes, in one brief year, the one turns into the other.

This beetle dies, and leaves behind a hundred little cells, parts of its own body and the body of its mate. These paired cells, the fertilized eggs, grow rapidly into the form of the clumsy, helpless grub which feeds upon the leaves, only to break up and form themselves again into this armor-plated creature of the beetle world.

There must be something as radically wrong with our individualistic ideas of today as there was with the conception of a flat world which prevailed before the time of Columbus. Perhaps if we stop trying to think of these manifestations of beetle life as individuals and think of them as parts of one great organism scattered over the surface of the earth, these striking differences will seem no stranger to us than do the differences in the various stages of a flower's life. The beetle forms inside the grub and the tulip flower bud forms inside the bulb. If tulip flowers could fly, we should then have the strange spectacle of the opening of the scale-covered tulip bulb and the coming forth of the gorgeous colored flower which sailed away to shed its seeds in someone else's garden. I think that this is the way we must look at it if we would get a clear idea of this strangest of phenomena,--metamorphosis.

[Ill.u.s.tration]

THE JUNE BEETLE LARVA

(_Allorhina nitida_, Linn.)

How is it possible that this fat creature, with eye-like breathing pores along its body, whose legs are worthless, and which is so helpless that it has to turn over on its back to wriggle over the ground, can change into the emerald-green June beetle which wings its way like an aerodrome across the meadow? This is the apparent miracle of metamorphosis which it has well-nigh baffled the intellect of man to explain.

Though the reasons for it are still unknown, modern research has shown us how this incredible change has taken place.

When this creature, which has grown a hundred times its size since it was born, has reached the age for this great change, it doubtless feels the impending transformation coming, and instinct tells it to crawl away into some protected nook or corner and pupate underneath the protection of a silken coverlid of its own spinning.

The change begins; each organ goes to pieces, disintegrates, becomes a ma.s.s of disconnected cells, so that the body filled with these, becomes, as it were, a bag of mush. This mushy fluid has been likened by entomologists to the disintegrated tissues which inflammation causes in our own bodies. If, then, you should slit it open at this stage, you would find no alimentary ca.n.a.l, no salivary glands, no muscles, simply a thick fluid, with here and there a thicker lump, that is attached at certain places to the inside of the sac wall. These lumps are formed of groups of active cells which were not disintegrated in the general breakdown of the muscle tissue, and these form the nuclei around which the new creature is to be built. These groups of cells grow rapidly, feeding on the fluid ma.s.s of broken-down tissue much as a young chick inside the egg feeds on the yolk, and builds up the whole complicated structure of the winged beetle, which seems to have no possible relations to the white grub out of whose body it was made.

It is as though the insect hatched twice, first from the almost microscopic egg its mother laid and from which it emerged as a tiny little creature in the image of this grub, growing and manufacturing from the leaves it eats enough nitrogenous matter so that when it emerges again from the yolk-like substance of its coc.o.o.n it will be a full-grown beetle, for it must be remembered that once made the beetle never grows.

This wonderful process is the same which is gone through by every flying insect that has a grub or caterpillar stage.

[Ill.u.s.tration]

ONE OF THE JUNE BUGS OR MAY BEETLES

(_Lachnosterna quercus_, Knoch)

Of the wild creatures of our back yards, none is better known than this hard-sh.e.l.led buzzing creature, which whirs into the circle of light around your lamp and commits suicide, if you will let it, by flying into the flame.

It is one of the so-called June bugs, or May beetles, which every boy and girl knows, and is not the June _beetle_ of which the larva was shown previously.

Its hard, pitted skeleton covers it completely, and it is most interesting to watch it open its wing covers with great deliberation, unfold the wings which are carefully stowed away beneath them, and holding its wing covers elevated so they will not interfere, start the transparent wings into motion and fly away with the whir of a miniature aerodrome. Indeed, it was this resemblance which caused the members of the Aerial Experiment a.s.sociation to name one of their first aerodromes after it, and the first trophy ever given for an aerodrome flight was won by Curtis's "June Bug."

This creature's first life is spent beneath the sod of your lawn, where it curls up around the roots of the gra.s.ses and clover and other plants which you do not want it to eat, and the first year of its subterranean existence it is the white grub, with the brown head, which everybody knows. At the end of the second summer of its life it changes to a soft brown beetle, which throughout the winter is hardening its sh.e.l.l preparatory to coming out in late spring as a winged creature to feed upon the leaves of trees. The beetle which is walking toward you lives upon the oak.

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ONE OF THE TWIG-PRUNERS

(_Elaphidion atomaric.u.m_, Dru.)

The long-horned beetles, as they are called, are remarkable for the length of their antennae and for their eyes of many facets, which almost encircle the antennae at their base. They have, like other beetles, two lives, so to speak, and their grub-life is spent inside some twig or branch, burrowing and living on the juices which their stomachs extract from the sawdust made by their jaws. They kill the twig they burrow in, so that the wind blows it to the ground, and they go through their transformation on the ground. The story is told of a long-horned beetle, belonging to a different species, that lived for years in its larval stage, burrowing patiently into the dry wood of a boot-last or shoe-stretcher, trying vainly to get enough nourishment out of it to make a beetle of itself.

[Ill.u.s.tration]

THE PREDACEOUS GROUND BEETLE

(_Chlaenius aestivus_, Say)

This creature almost anyone will recognize as a beetle. It is built for running, and its jaws are made for fighting. You have only to catch one and watch it open and shut its jaws to realize that it would bite you if it could. But for all that it is a great friend, for it is what the entomologists call predaceous, and at night or at twilight it hunts everywhere for the larvae of insects which attack the plants we live on. In its larval state, in which it looks for all the world like a centiped without the "ped," it burrows in the ground in search of the plant destroyers, which think to escape notice by getting under the cover of the soil. It is by nature, then, opposed to the vegetarians, the herbivores, and hunts them wherever they are likely to occur.

When you see a black or dark-brown beetle running swiftly from under some stone or log whirls you have just turned over and which makes faces with its jaws as though it would chew your fingers when you pick it up, you can be quite sure in eight times out of ten that it is one of these carabidae or predaceous ground beetles, and if you let it drop from your fingers you may be saving the life of a friend, because some day it may eat the worm which, lying close to some pet flower of yours, had planned to cut it off beneath the ground.

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.

[Ill.u.s.tration]

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.