verybody has seen tumble-bugs rolling their dust-covered balls along some path or highway in the country, but few people are aware that these little insects are the lineal descendants, so to speak, of a deity—the sacred scarabæus of the Egyptians, of which we have read so much. The little fellows, in seeming indifference to their fall from high estate, are still rolling their balls as industriously as they did on the banks of the Nile in Moses's time.
The coleoptera, or beetles, form the highest division of insects. They all have six legs, and a distinctly marked head, thorax, and abdomen. The body is covered with a horny envelope, which takes the place of the skeleton in higher creatures, protecting and holding the organs in place. The beetle has also four wings, one pair over the other. The lower ones are of a parchmentlike substance, while the upper ones are horny.
Beetles are of various kinds, some of which are useful to man, and others harmful. Scavenger-beetles belong to the former class, and no one variety is more interesting than the pellet-beetle or tumble-bug.
This little fellow, of one species or another, is found all over the United States, in Europe, and in northern Africa. With us he is from half to three-quarters of an inch in length, and coal-black.
The most remarkable thing about tumble-bugs, and one which excites the curiosity of every one who observes them, is the manner in which the egg is developed into the perfect insect. This egg is laid in manure, which is mixed with a little clay, and then rolled into a ball about the size of a marble, and left to dry. For the work that is to follow, the powerful legs and jaws of the insect are well adapted. No better proof of its strength may be obtained than by putting one or two bugs under a candlestick on a table, and noticing the ease with which they move it along.
When the ball is dry, the bugs, usually two in number, commence rolling it to a suitable place of deposit, which is not, apparently, selected in advance. Whether these two bugs are the parents or not is unknown, but at any rate one places himself in the front, with his hind feet on the ground and the others on the ball, while the other goes in the rear, with his body reversed—that is, his four front legs are planted firmly on the ground, with his head bent low in the dust, while his hinder parts are raised high on the ball, which he pushes with the two remaining legs and the extremity of the body.
The duty of the bug in front seems to be either to guide the ball or to pull it forward, possibly both. Although he has the most natural position, and seems to have less to do than the other bug, he really has the harder time, for when the ball gets rolling down a slope it frequently goes over him entirely, or pushes him sprawling by the way-side. But he is soon on his feet again, and scrambling into place, makes believe he is having the jolliest time in the world.
If obstructions occur in the path, the tumble-bug is not easily discouraged. You may frighten him away, or even push him aside with your stick, but if you keep quiet for a few moments he will return to his work. If a tuft of grass or a stone intervene, he leaves his work and goes in search of help, and his comrades rarely fail to respond. If, however, after repeated efforts to move it, the bugs leave their ball in despair, it often happens that a new party comes across it and rolls it merrily to its destination. The whole community seem to take an interest in every ball, and are willing to do their utmost to help it along.
When a suitable place is found, which may be several yards from where the ball was made, one bug remains with it, while the other excavates a little hole for its reception. When the hole is about the depth of the ball, the latter is rolled in, and then both bugs get underneath, and while they are excavating and pushing the dirt one side, the ball gradually follows them downward, sinking by its own weight. This hole is sometimes two or three feet deep.
When the egg hatches, the larva, or grub, lives upon the contents of the ball until the supply of food is exhausted, when it makes its way to the surface of the ground, and there, by some unknown process, forms and places itself inside a cocoon of oval shape, and of similar composition to the ball in which it was hatched. There it silently changes into a chrysalis, and emerges a perfect insect.