At the beginning of April, I take three batches of larvæ of Cetonia floricola chosen from among those most fully developed and therefore liable to undergo their transformation during the course of the summer. At this April season the great hunger sets in which doubles the size of the grub and amasses the reserves needed for the elaboration [[249]]of the adult. The three batches are installed in large tin boxes, carefully closed, in which there is no danger of too rapid desiccation.
The first batch consists of twelve grubs, which are given an abundance of food, renewed as the need arises. My prisoners could not be better off in the heap of leaf-mould, their favourite resort.
Side by side with this gastric paradise, a second tin, a very inferno of starvation, receives a dozen larvæ kept absolutely without food. It is furnished—as, for that matter, are the others—with a litter of droppings, enabling the famished creatures to wander about or bury themselves at will.
Lastly, the third batch, likewise twelve in number, receives from time to time a scanty pinch of rotten leaves, enough at most to beguile their mandibles for a moment.
Three or four months go by and, when the torrid heats of July have come, the first tin gives me the perfect insect. Its development has been accomplished without a check: the twelve grubs are succeeded by twelve magnificent Cetoniæ, resembling at all points those who sip and slumber in the roses when the spring comes. This result convinces me [[250]]that the defects attaching to rearing in confinement have nothing to do with what remains to be told.
The second tin, in which strict abstinence is enforced, provides me with two chrysalids, whose diminished size indicates the presence of dwarfs. I wait until the middle of September to open these caskets, which remained closed when those in the first tin burst, two months ago. Their persistent refusal to split open is explained: each of them contains nothing but a dead larva. Absolute starvation was too much for the grubs’ endurance. Of the twelve kept without food, ten shrivelled up and eventually died; only two managed to wrap themselves in a shell, by gluing the droppings round about in the usual way. This was their last effort. The two grubs, incapable of performing the consummate labour of the nymphosis, perished in their turn.
Lastly, in the third tin, where victuals were very sparingly provided, eleven grubs out of twelve died, worn out with privation. One only has enclosed itself in a cocoon, which is correctly made but very much reduced in size. If there is a living insect within, it can only be a dwarf. In the middle of September, I [[251]]open the cabin myself, for there is nothing yet, at this late period, to announce an impending natural fracture.
The contents fill me with delight. They consist of a Cetonia, alive and kicking, all brilliant with metallic gleams and streaked with a few white stripes, like those of the species who have developed freely in the great heap of earth-mould. The shape and costume are not altered in any respect. As for size, that is another matter. I have before my eyes a pigmy, a little gem more exquisite than any collector ever found on the blossoming hawthorns. From the edge of the clypeus to the tips of the wing-cases this creature of my artificial devices measures thirteen millimetres,[6] no more. The insect would have measured twenty millimetres[7] if the grub had been properly fed, far away from my famine-stricken tins. From these figures we deduce that the dwarf’s bulk is about one-fourth of what it would have become normally, without my interference.
Of the twenty-four larvæ subjected, during three or four months, some to an absolute fast and others to a diet of meagre [[252]]mouthfuls administered at long intervals, one only reached the adult form. The bad effects of abstinence are far-reaching and the pigmy still feels them. Though the season when the caskets should have split had long gone by, he had made no attempt to free himself. Perhaps he had not the necessary strength. I myself had to break open the cell.
Now that he is free and revelling in the light, he kicks and struggles and starts running, if I tease him at all; but he prefers to rest. One would think that he was overwhelmed by an insurmountable lassitude. I know how gluttonously the Cetoniæ attack fruit at this warm season, gorging themselves upon the sweet pulp. I give my dwarf a piece of juicy fig. He does not touch it, preferring to doze. Is it not yet time for him to eat, after his forcible liberation? Was the recluse intended to spend the winter in his shell before tasting the joys but also risking the dangers of the outer world? It may be so.