Popular Science Monthly/Volume 43/August 1893/Some Remarkable Insects
|SOME REMARKABLE INSECTS.|
By WILLIAM J. FOX.
THE great majority of persons have no idea of the numerous and singular forms of insects. They are all called "bugs" by most people, yet not one tenth of their number are really bugs. These latter are classed by themselves and are called Hemiptera. Beetles are not bugs, being totally different things, and form what are known as the Coleoptera, which means sheath-wing, because of the two large plates on the back that cover the true wings, which consist of thin membrane. These covers are called elytra. The butterflies and moths form another one of these orders, being called Lepidoptera, or scale-wing, on account of the tiny scales with which the wings are covered. No doubt many of the readers of this article have noticed the powdery substance which comes off a butterfly or moth on handling it. These are the scales, and, should any reader possess a microscope and place the wing or part of one under it, I think he will be repaid for his trouble. The "dragon flies" and "devil's needles" form the order Neuroptera, which means vein-winged. So it is with the flies and the bees, wasps, and ants, the flies being called Diptera, i. e., two-winged, and the bees, wasps, and ants, Hymenoptera, or membrane-wing. It will probably be said by some that ants have no wings; but this is only the case with what are called neuters or workers, the males and females being provided with wings. The total number of different kinds of insects that are known at present is over two hundred thousand, of which beetles alone number one hundred and twenty thousand—this being about twice as many as all the other known animals together. It is estimated that the actual number of different kinds of insects in the world is over one million.
The Orthoptera, to which grasshoppers and roaches belong, present many oddities; foremost among them, in the United
Fig. 2.—The Walking Leaf.
States, is the mantis or "praying mantis." It is very common throughout the South. It will be seen that the fore legs are armed with strong spines or teeth, used for securely holding any insect that may fall into its clutches. I have seen this insect leisurely devouring flies held between these legs. From it there was no chance of escape. A specimen observed in captivity washed itself in the same manner as a cat, rubbing its head and face with its fore legs. In South America a species of mantis is said to seize and devour small birds.
Another strange orthopter is known as the "walking stick," which so closely resembles the stems of plants upon which it lives that it is very difficult to find them. One species (Diapheromera femorata) is abundant in the Middle States. This species is green when the foliage upon which it lives is of that color, but when this changes in the autumn the color of the walking stick changes also. It is said to do great injury to oak and other trees.
In the East Indies is found an insect that greatly resembles a leaf, both in form and color, as will be seen by the figure on page 528. It is very appropriately called the "walking leaf" and is known to scientists as Phyllium siccifolium. There are about a dozen species of these insects known, all of which are from the Oriental regions.
In southern Europe there is found a peculiar insect that belongs to the Neuroptera, the same order as do the "dragon flies," "devil's needles," "snake doctors," etc. The scientific name of this insect is Nemoptera coa. It will be seen that the first pairs of wings are very broad, but this is not the peculiar part of it; it is the hind pair that are remarkable, being extremely long and narrow and a little broader toward the end, which gives them the appearance of paddles. There is nothing more in this group of insects that is very striking.
We will now take up the Hemiptera, of which the well-known bedbug is an example. One species from tropical America (the Diactor bilineatus) has very slender legs, except the tibiæ of the hind pair, these being broadly expanded. What use these expansions are to this insect is not known.
Another singular species, one that is found throughout most parts of the United States, namely, Ranatra fusca, inhabits ponds and other streams. It is known to destroy the eggs of fishes and to attack young fish. It is when they attack fish that their stout fore legs come into play, being used for grasping and holding any unfortunate fish that should fall within their reach. It will be seen how well adapted these legs are for the purpose.
Among the beetles, or Coleoptera, there are many curious forms, of which I will only mention a few of the most prominent. Acrocinus longimanus, the "long-armed" beetle, as it is called, has the fore legs greatly elongated, being twice as long as the body and about three times as long as either of the other legs. It inhabits tropical America, where it is said to be quite abundant.
The giants among insects belong to the genus Dynastes, and to several allied genera. Of Dynastes, one (D. hercules) found in
Fig. 6.—Dynastes hercules.
Africa attains a length of six inches, and is remarkable, not only for its great size, but for the long, curved horn which projects out from the thorax; beneath this horn there is another much shorter one, which projects from the head, being armed with several huge teeth. Insects of the male sex only are provided with these immense horns, those of the opposite sex being quite a different-looking beetle, being without any trace of these projections. There is a species that inhabits the southern United States that also belongs to this genus, but it is much smaller, being about two and a half inches long.
The "stag beetle" of Europe is another strange form, the mandibles of the male being greatly enlarged. From the shape and size of the jaws one would suppose that this insect is predaceous, but it is on the contrary a vegetable feeder, using its great jaws to wound the plant, which causes the sap or juices to flow, upon which it feeds. The jaws of the females are in no way conspicuous. There is also a closely allied species found in the United States, but it is a smaller insect. Many other curious forms are found among the beetles, but they are too many to mention.
The Lepidoptera, or butterflies and moths, have a few odd forms among them. One of the most interesting is what is known as the "dead-leaf" butterfly, found in the Malay Archipelago. The under side of this butterfly greatly resembles a dead or dried leaf, so much so that it is next to an impossibility to detect it when it alights among withered bushes. Wallace, in his book The Malay Archipelago, says of this insect: "Its upper surface is of a rich purple, variously tinged with ash color, and across the fore wings there is a broad bar of deep orange, so that when on the wing it is very conspicuous.... I often tried to capture it, without success, for, after flying a short distance, it would enter a bush among dead or dried leaves, and, however carefully I crept up to the spot, I could never discover it until it would suddenly start out again and then disappear in a similar place. At length I was fortunate enough to see the exact spot where the butterfly settled, and, though I lost sight of it for some time, I at length discovered that it was close before my eyes, but that in its position of repose it so resembled a dead leaf attached to a twig as almost certainly to deceive the eye when gazing full upon it." In tropical America there are a number of species that have wings so transparent that it is possible to read small print through them. Among the moths the "death's head" of Europe is remarkable for having on the top of the thorax the figure of a skull and crossbones. It is an object of great terror to the ignorant classes, and it is said "has more than once thrown a whole province into consternation, the people thinking it was some infranatural being sent upon the earth as q, messenger of pestilence and woe."
The Hymenoptera, which include the bees, wasps, and ants, contain a number of interesting forms, especially among the ants. The "umbrella ant" of Brazil has a tremendous head in proportion to its body, as will be seen by the figure. It has received the name of the umbrella-ant because of its habit of cutting out round pieces of the leaves of orange and coffee trees, which it carries by its jaws in an upright position, so that it looks as though it were utilizing its burden to keep off the heat of the sun.
The "driver ant" of Africa, the sting of which is compared to the thrust of a red-hot needle, is another interesting subject. These ants are totally blind, and, when an army of them gets on the march, all animal life in their path gets into activity, for woe to any living creature of small and even large size that should fall into their power! They also enter houses, driving the inhabitants from them, but on the return of the latter, after the ants have left, they find their place of abode cleared of all vermin; rats, mice, and all other pests of the house are destroyed by these scavengers. The largest serpents, if gorged, will fall a victim to these remorseless creatures. They have been known, when a stream interrupts their journey, to actually link themselves together and form a floating bridge, over which the rest of the army passes. When a stream is too rapid for such a bridge, they form a suspension bridge by hanging from a friendly branch, and when wafted across by a breeze, they firmly anchor on the opposite shore, thus allowing the rest to cross in safety, and swing over themselves when the others have all crossed.