Читать книгу Intelligence in Plants and Animals - Thomas G. Gentry - Страница 15

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Hardly a person living in a sandy country district can be found who has not seen or heard of the queer little insect called You-ee-up, a name which the books do not give, and of which writers on entomological subjects seem to be ignorant. The learned call him Myrmeleon, or Ant-lion, and very appropriately too, because, like the great king of beasts, he never attacks his prey in the open field, but by stratagem while lying in wait in some hidden retreat or secret covert.

Should you chance, on a warm summer day, where sunny slopes abound on the outskirts of a woods, or by the side of a frequented path or road, look carefully about and soon will you descry a small funnel-like opening, scarce two inches in depth and in width, upon a bare patch of sand in the midst of an ocean of verdure. This little cavity is the intentional work of the larva of the Ant-lion. A very close scrutiny will show, by the presence of a pair of fierce jaws, the Ant-lion at home.

Would you know the ingenious builder? Lift him out tenderly from his burrow of sand, and when you have placed him upon the palm of your wide open hand, note with the most careful exactness the peculiar make-up of his structure, so that in the future you may have little difficulty in recognizing him should you again meet.

His short, flat head, armed with powerful mandibles, heavy-set chest, and large, soft, fleshy abdomen, amply protected on the sides with stiff, bristly hairs, added to his compact, robust form, the forward projection of his front and middle legs, and the backward prolongation of the stronger and less movable hind ones, which eminently adapts them to a backward manner of walking, are characters which so deeply impress, that we cannot fail to call up, when occasion demands, the possessor of so wonderful a mechanism.

YOU-EE-UP IN HIS DEN.

As He Appears in Youth and Old Age.

Now that you have become familiar with the odd creature in form and in mien, set him once more upon his proud realm of sand, and seat yourself on the bank close by to watch and enjoy his curious behavior. In a minute or two his fears will have subsided, and he in control again of his accustomed indifference. See, he moves. Round and round he turns in the loose grey sand, burying himself deeper and deeper, and throwing the grains out from the hole he has made by his twistings, using his short, flat head for a shovel. The sand, as it is thrown over the side of the burrow, forms quite a margin, and when all is completed the Ant-lion sinks himself deep into the bottom of the trap he has digged, leaving only the tips of his mandibles in sight, which are extended and ready to seize any insect that is so luckless as to fall into their reach.

The unfortunate ant that ventures too close to the margin sets the sand off rolling, and it immediately begins to struggle against falling down, but the Ant-lion throws a few shovelfuls of sand against it, and it soon comes tumbling down to the bottom of the funnel, when it is instantly seized between the sharp mandibles in waiting, which, being perforated by slender tubes, enable their blood-thirsty owner to suck out its juices.

Country children, and adults as well, manifest a deep interest in these strange beings. They call them, as has been intimated before, You-ee-ups. How the name originated, and when, I do not pretend to know, nor have I been able upon inquiry to find out from the oldest inhabitants of the regions they affect. Old men and old women in the seventies and eighties knew these insects by this name when they were children, and I have been informed that they were always so spoken of by their fathers and mothers.

Even the insects themselves are believed to know the odd name by which they are designated. So fixed is the belief in the minds of the many that, to contradict it, is sure to subject the person so rash and presumptuous to the grossest abuse from the friends of the strange little creature. They have seen him in his sandy retreat, and have called him by name, and he has never been known to decline a response. “You-ee-up, you-ee-up,” cries one, with his mouth just over the opening, and up comes the strange “crittur” as obedient as a lackey. “You-ee-down, you-ee-down,” says the same childish voice, and down he goes to his den to await, as is thought, the giving of further orders.

That the Ant-lion does seem to respond when called, cannot be denied, for I have tried the experiment myself, and others have tried it in my presence, and always with the same successful results. But people go through the world not only with their eyes closed and their ears sealed, but also with their minds forever locked against thinking, lest, by thinking, they might do themselves serious injury. Had but a little of thinking been done, or some common sense exercised, the solution of the insect’s strange actions could have been reached without any great difficulty.

Let me briefly explain. One cannot talk, as is well known, without some motion being imparted to the outlying air. This moving air impinging upon the loosely arranged sand piled up around the margin of the tiny pitfall, dislodges some particles, and these, falling into the jaws of the hidden Ant-lion, bring him to the surface, for he ascribes the commotion to some ill-fated ant, or other such insect, that has, in its anxious searching for food, tumbled unconsciously into his artfully-laid trap. In a moment the mistake is discovered, and, with all possible dispatch, he backs himself down into his den to await further developments. His appearance on the occasion is greeted by “you-ee-down, you-ee-down,” and as he goes down apparently in obedience to the order, but really because it is a matter of business so to do, it is claimed by the unlearned and unwise that his movements are responsive to the command of the person by whom he is addressed.

Two years of larval life, and the subject of our sketch is lost to the sight of the rural folks. A new life, where feeding is no longer necessary, awaits him, but one in which the most radical changes must occur if he is to fulfil the existence which nature designed in her grand scheme of creation. From a silk-gland, which, unlike those of the butterflies and moths, is situated at the end of the body, he spins a cocoon, but there being so little of silk to spare, he needs must supply the deficiency by the utilization of a quantity of sand, which he glues into the walls of his house. Here he dwells a comparatively inactive pupa for three brief weeks, retaining his large, powerful mandibles to the last, which he uses in cutting his way out of the cocoon, when he is ready to emerge as a winged neuropter. In the adult form he resembles the dragon-flies in flight, flapping wildly and irregularly about, as if his muscles were too weak to wield his great stretch of wings. But in repose his alar appendages are folded above each other, forming an acute-angled roof above the long, slender abdomen. The antennæ or feelers are short, stout and club-shaped, and the wings long, narrow and densely veined.

Myrmeleon obsoletus, a name given to this insect by Thomas Say, a naturalist of repute, who lived in Philadelphia in the early half of the present century, is by no means a rare species, if search is made in the proper places. In the cut the larva is found to the right of the burrow, while deep in the bottom, with the jaws only in view, is another, prepared to receive the small ant just above should it lose its foothold and tumble into the trap. On the wing, a little in the background of the picture, may be seen the adult insect, represented in hawking for prey over a meadowy expanse of country.