Thus in the economy of Nature every insect appears to be food for some other. On the leaves of the Virginia creeper you may usually find, in early autumn, some caterpillars which have received the eggs of a small chalcid fly. These caterpillars, otherwise so large and green and awesome to the beholder, have become limp and lean and have an aged and decrepit look. They hold feebly to the vine but no longer eat anything. I brought home one of them and in a short time there emerged from its body a great number of small white grubs, fifty or more by actual count. Upon the back of their emaciated host they proceeded to spin for themselves marvelous little cocoons of white silk which they did in a very brief time. Moving their heads this way and that they spun the fine threads about themselves until they were completely enveloped. Here were a great number of little spinners, making for themselves garments of silk, and at last spinning themselves out of sight. The caterpillar now bristled with the small white cocoons which stood upon end on its back, where they were attached, and almost hid it from view.
The wary caterpillar has many foes. If it escapes the hungry warblers and vireos, there is still the army of goggle-eyed wasps and nervous ichneumons to circumvent. Yet a prodigious number survive. Were it not for their enemies they would overrun the earth. The butterflies sporting in the sunshine, and the small moths flitting about the lamp, have come through many perils, and may almost be said to have lived by their wits, so astonishing are the ruses they have devised to deceive their pursuers.
[THE WAYS OF THE ANT]
If you would see the ants to advantage—to your own, that is—you must turn over a pasture stone under which one of the species of small yellow ants has its nest. By thus gently removing the roof, if it is a good-sized stone, the whole colony will be in view at once. The red-ant hill presents difficulties. To dig into it or to pull it apart is quite useless, as the earth falls in and nothing is to be seen but a struggling heap of dusty and indignant ants. It rarely happens that such a hill may be built around a small boulder. If this boulder is suddenly and deftly removed, not dragged or rolled aside, but lifted clear of the hill so that the sides of the nest may not be broken in, a remarkable scene is disclosed.
I have found such an ant hill, and by removing the stone the household was placed on exhibition—but not all its secrets revealed by any means. From several large chambers, now roofless, galleries and corridors radiated in all directions. The instant the stone was lifted the ants swarmed from the galleries into these chambers, which were packed with the large cocoons. There were thousands of pupæ, of a delicate brown tint, looking wonderfully clean and fresh, but with such celerity did the ants work that inside of ten minutes all were carried from view.
Among the rest were perhaps a dozen young ants, the head and thorax being white and the abdomen a pale mauve. These creatures moved feebly about, taking no interest in the proceedings, and were for the most part seized by the workers and conveyed into the galleries. Apparently they were individuals that had just emerged from their pupa-cases.
Under another large stone were two very numerous colonies living side by side, of different species. The nests were, of course, entirely separate and under opposite ends of the stone. The smaller of the two appeared to be stinging ants, for they clustered in great numbers over their small pupæ, elevating their abdomens in a threatening manner like so many diminutive scorpions. The other species were large and active ants of a polished bronze hue. Their pupæ were naked, which gave the nest the appearance of being filled with grains of rice.
These large ants set to work with frenzied activity and removed all of their own pupæ. Then, and not until then, they swarmed over into the adjoining nest and began carrying the cocoons of the small ants back into their own nest. Now and then some small ant bolder than the rest would resist, and an individual combat ensued which ended by the large ant carrying off her small antagonist. There was, however, very little resistance of this sort, and the pillage, if such it were, continued until the remaining cocoons had all been carried over into the nest of the large ants. So few of the small ants made any resistance that it gave one the agreeable impression the larger ants were only offering assistance. But I failed to find on subsequent visits that they had returned the pupæ. And although they daily brought their own pupæ out of the galleries, the smaller cocoons never more came to view, and the small ants subsequently abandoned their nest. Thereafter I felt some compunction in thus disturbing a whole community for mere curiosity.