(_Scudderia sp._)
How marvelously equipped such a creature as this is to live! The great eyes, with many facets, enable it to see by night as well as by day. Its long, slender antennae catch the faintest odor, and probably are sensitive to a host of perfumes that we do not know. In the front of each fore leg, just below the knee, is a dark, sunken area, the ear, with which it can probably hear sounds too faint for our ears, and by moving them can tell from which direction the sounds come. Its long muscular legs enable it to jump a hundred times its length whereas man can scarcely cover three times his length at a leap. Its wings not only enable it to fly well, but in the males are provided with an apparatus near their base for making a musical sound.
This sound is made by half opening the long green wings and closing them again rapidly.
The left wing bears a file on its inner surface near the base, while the other, the right wing, has a sharp knife edge on the outside just below the file on the left wing. In closing the wings together the knife edge sc.r.a.pes across the file and makes at least one of the wings vibrate. While the wings are opening no sound is produced; as they close the characteristic sounds so like the words "Katy did" are made.
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THE NARROW-WINGED KATYDID
(_Scudderia sp._)
If it is any comfort for sleepless ones to know it, the katydid is one of the noisiest creatures of its size in the world. It is only the males which call their "Katy-did, Katy-didn"t, she did, she didn"t," and they are calling to their mates.
There are people who prefer the noises of the street-cars to the noises of Nature, and who complain that the buzz of insect life on a summer evening makes them feel lonesome and unhappy, but to me half the mystery and charm of tropical life lies in the music of the night insects. Our southern states, with their tropical summers, have a wealth of insect life quite comparable to that of the tropics and vastly more varied than that of northern Europe.
The katydid is the greatest songster of this night choir and is a truly American species--as truly a thing to be proud of as the mocking-bird.
Lafcadio Hearn in his "Kusa Hibari" has put us in touch with the soul of a j.a.panese katydid, and if ours did not have quite so shrill a voice we too might domesticate him, but the idea of caging an American katydid as the j.a.panese do their tiny-voiced creatures will not, I fear, appeal to the average American citizen.
The male of this species sings sometimes by day as well as by night and has different calls for day and night.
The female lays her eggs in the edges of leaves, thrusting them in between the lower and upper cuticle, and from these hatch out the wingless, long-legged green creatures which are hopping everywhere about the gra.s.s in early summer.
They are borne for the summer season only, and with the frosts of winter they all die off. Nature seems to make just as complicated a being whether it is to last a score of minutes or a hundred years--one season or a hundred is all the same to her.
Just why the katydid should want to hear its own song some city people may wonder, but it is evident that he does, for just below each knee, on his foremost legs, is to be found a well-developed ear with a tympanum which probably vibrates much as ours do.
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A YOUNG KATYDID
(_Scudderia sp._)
It is doubtful if there are any animals so largely legs as the young katydid. It cannot fly yet, for the wings upon its back are still too small to carry it through the air, but it can escape from its enemies by jumps which put those of a gazelle or a kangaroo to shame. The muscles in its legs are like our own muscles so far as can be determined, except that they are attached to projections on the inside of a skeleton which encases them all, instead of being attached to the outside of a skeleton which they themselves encase, so when a katydid jumps one cannot see the muscles move as one can those of a horse.
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THE CRICKET ON THE HEARTH
(_Gryllus pennsylvanicus_, Burm.)
Through the ages, who knows if not from the times of the cave-dwellers, this friendly visitor of the fireside has rubbed his rough wings together over his head and sung man to sleep. The European form seems quite as domesticated as the cat or dog, leading nowhere a truly wild life, and it may be questioned whether any living creature has become more a part of human life than the cricket on the hearth.
The carrying power of their song is extraordinary; there are species whose strident notes can be heard for a mile, although their little bodies are scarcely more than an inch in length. The males alone are musical, and it is reasonable to suppose, since the females have ears in their fore legs, that they are singing to their mates and not to mankind.
As one listens to their friendly song it is hard to appreciate what fighters they are among themselves, the larger ones even turning cannibals when food is scarce, although a glance at the photograph shows how well equipped they are for battle. Their great black eyes, only shinier black than their coal-black armored necks, their jointed palpi with which they feed themselves, their thick, leathery wings pressed against their sides like a box cover, and their strong, muscular, spiny hind legs, with which they jump a hundred times their own length, do none of them contribute to beauty, though quite in keeping with their armored war-horse appearance.
Two long, flexible circi protrude like tails behind, but the task of finding out what they are for has been too difficult for man. Perhaps the strange nerve-ending hairs which they bristle with may be sensitive to vibrations of the air, of which we yet know nothing.
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THE GROUND CRICKET
Unlike its jet black relative of the fireside, the striped ground cricket forages by day on gra.s.sy slopes. It is a more omnivorous scavenger than the hyena, for it eats decaying plants as well as animals.
Its big brown eyes, which cover half its head, see, doubtless, many ways at once, and its long, whiplike antennae, which it waves constantly as it springs through the gra.s.s, are believed to scent odors which are inconceivably faint, such as the odor of a blade of gra.s.s, a pebble, or a decaying leaf.
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THE STONE OR CAMEL CRICKET
(_Ceuthophilus uhleri_, Scudd.)
It would not be a good idea to let the children think that creatures such as this were prowling round the house at night--that is, unless you a.s.sure them that it is only a harmless, tawny yellow stone-cricket from the shady woods, where it generally hides under stones and damp, decaying logs.
It seems strangely equipped for its night life, for it has antennae as long as its body. I cannot help wondering if these help it to jump in the dark.
Fabre, the great French entomologist, has tried, as others have, to find out just how the insects use their antennae and what they are really for.
He says at last, "our senses do not represent all the ways by which the animal puts himself in touch with that which is not himself; there are other ways of doing it, perhaps many, not even remotely a.n.a.logous to those which we ourselves possess."
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A MONSTER OF THE UNDERWORLD: THE MOLE CRICKET
(_Gryllotalpa borealis_, Burm.)
The creatures of the air which hide away their eggs that their larvae may hatch out underneath the ground must reckon with this burrowing beast.
All his life long he tunnels beneath the ground from place to place. When you think of how long it would take you, even with the best tools, to dig a hole in the ground big enough to crawl into, you will get some idea of the power which these two front legs, four-pointed like a spading fork, must have, to enable such a creature to disappear into the ground in a few seconds as he does. These paws, proportionately many times more powerful than bears" paws, are snippers too, for moving back and forth behind them is a sharp-edged instrument which, like the shuttle-bar on a mowing machine, shears off the gra.s.s roots which interfere with the mole cricket"s progress through the ground. The poor defenseless angleworms must fall an easy prey to such a foe as this!
Upon the first joint of each clumsy front leg, it has a narrow slit-like ear which is but faintly visible in the photograph. Can you imagine a male and female calling to each other through the long and winding pa.s.sageways beneath the ground? Possibly they call to each other only in the night-time, on the rare occasions when they venture out above the ground.
He is a curious creature with eyes that are only rudimentary and a noxious smell that he emits if he is touched.
The female excavates a chamber near the surface of the ground and lays her eggs in it to be incubated by the sun"s heat, as are most insects" eggs.
For some time it was supposed that both parents devoured their progeny, as many as 90 per cent being eaten up, but a French observer, Monsieur Decaux, has found that the male alone is the cannibal and the mother, far from doing this, watches over them and when they hatch she feeds the little ones with bits of plant roots, earthworms and the larvae of various insects.
The discovery of one of these mole crickets is really an event. Most people see but one or two in all their lives. In Porto Rico, however, there is a form with longer wings which eats the roots of sugar cane, tobacco and other crops so that the "changa," as it is called, is considered the most serious insect pest in the island.
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