Evening Republican, Volume 18, Number 259, Rensselaer, Jasper County, 2 November 1914 — GIANTS and DWARFS of the INSECT WORLD [ARTICLE+ILLUSTRATION]

GIANTS and DWARFS of the INSECT WORLD

by HAROLD BASTIN

people believe that jp.ll insects are very small; and in a certain sense this is true, for the largest known insect appears diminutive when con- • trasted with the vast bulk of such a creature as a whale or an elephant. But this is hardly a fair comparison, because insects are in every way dissimilar to vertebrate animals, having developed along entirely different lines. In place of physical hugeness we find amazing delicacy of structure and adjustment; and if we liken the vertebrate to a locomotive engine, the Insect must be represented by a lady’s watch to complete the metaphor. In line, multum in parvo has been the ■watchword of insect evolution. Nevertheless, when judged in their own sphere, insects display a remarkable range of size. Take, for example, the beetles. The largest living representatives of the clan are the Goliaths of Africa and the Megasomas of tropical South America. A fair-sized male specimen of the latter measures four and a half inches from the tip of the horn to the extremity of the abdomen. The male of the Hercules beetle, also of South America, may be two inches or more longeif but wellnlgh half its length. Is made up by the great hornlike process which springs from its thorax. A good idea of these beetles’ huge proportions may be gained by placing one of them side by side with a common two-spot ladybird. Yet the lady- ’ bird is by no meahs a small beetle as beetles go. Comparisons no less striking may be made among the moths. The largest British moth is the “Death’s Head” —a truly noble Insect with a wing expanse of four and a half inches. But its proportions are sadly .dwarfed when we contrast them with the huge Owl moth —the Noctua strlx of science—which is not uncommon In many parts of South America. f _ It may measure ten inches or more •cross. Then there is the giant Atlas moth, from India, which may measure as much as a foot from tip to tip of the fore-wings. For the sake of familiarity we may place the little clothes moth of our wardrobes at the other end of the scale —though it is not .by any means the smallest of its kind. The Atlas and the Owl moths mentioned above have larger wings than any other living insects, so tar as Is known; but they are not the largest flying Insects on record, for some of the extinct dragon flies of the carboniferous period measured two feet •cross the wings. The largest British dragon fly, with a wing expanse of four inches, is a pygmy, contrasted size for size with one of its gigantic prehistoric ancestors. Among the largest existing insects must be reckoned the giant waterbugs, some of which attain a length of nearly five .Inches. In the United States these insects are known popularly as “electric light bugs,” because they have the habit at night of leaving the pools and lakes, where they get their living, and flying around arc lamps, especially when these are mounted upon high buildings. The British water scorpion is a well-known denizen of ponds and sluggish streams. It belongs to the same family as the giant bugs, besides which it may fairly be termed a dwarf. The longest of living insects are found among the phasmids, or “walking sticks.” Some attain nine inches from head to tail, while if the outstretched legs are included the measurement is much greater. Two of these strange insects are in marked contrast with a Stag beetle —the largest British beetle, by the way. Clearly these phasmids are “lohg drawn out” in a very literal sense of the phrase; but a few' of the species •re much heavier in build. This is the case with the very remarkable creature known as Eurycantha horrlda from Australia. It is not only long, but bulky, and what with its hard armor plate integument and formld-

able array of prickles, It looks a decidedly dangerous customer.' One is relieved to learn that its tastes are exclusively vegetarian. The vast majority of the hymenoptera (the ants, bees, wasps and their relatives) are comparatively small insects, but among the solitary spider-killing wasps (Pompilldae) we find some notable exceptions. Some of these giants measure two inches or more from head to tail, and withal are exceptionally strong and vigorous insects. The largest species are found In South America, where they deal death and destruction to the spider population. Even the formidable bird-eating spider—a grim and hairy monster with fearsome fangs—is attacked and destroyed. It should be noted that these wasps do not themselves eat the spiders that they kill, but store them away In cunningly contrived nests for the benefit of their young. Our little Pompllus viaticus (unfortunately it has no popular name) behaves in precisely the same way, but naturally chooses spiders proportionate to its own size. Even in this instance, however, the spider is usually several times heavier than

the wasp itself. For these “dwarfs” of the insect world are by no mean* weaklings, but on the contrary, possess marvelous muscular force and what certainly is a well-nigh Inexhaustible fund of energy. Probably most Insects are stronger, and more enduring, in proportion to their size, than any of the higher animals. They are always active, and apparently quite beyond the reach of fatigue while life lasts. But ceaseless, rapid movement imposes a serious tax upon the machinery. Consequently w® find that the insect is almost always short-lived. It is said that the worker hWfe bee literally wears herself out, and dies, after a few weeks of toil for the benefit of the commonwealth in which she plays this brief part.