The Sitaris in the full-grown state lives only for a day or two, and its whole life is passed at the entrance to the Anthophora’s galleries. It has no concern but the reproduction of the species. It is provided with the usual digestive organs, but I have grave reasons to doubt whether it actually takes any nourishment whatever. [[162]]The female’s only thought is to lay her eggs. This done, she dies. The male, after cowering in a crevice for a day or two, also perishes. This is the origin of all those corpses swinging in the Spiders’ web, with which the neighbourhood of the Anthophora’s dwelling is upholstered.
At first sight one would expect that the Sitaris, when laying her eggs, would go from cell to cell, confiding an egg to each of the Bee-grubs. But when, in the course of my observations, I searched the Bees’ galleries, I invariably found the eggs of the Sitaris gathered in a heap inside the entrance, at a distance of an inch or two from the opening. They are white, oval, and very small, and they stick together slightly. As for their number, I do not believe I am exaggerating when I estimate it at two thousand at least.
Thus, contrary to what one was to some extent entitled to suppose, the eggs are not laid in the cells of the Bee; they are simply dumped in a heap inside the doorway of her dwelling. Nay more, the mother does not make any protective structure for them; she takes no pains to shield them from the rigours of winter; she does not even attempt to stop up the entrance-lobby in which she has placed them, and so protect them from the thousand enemies that threaten them. For as long [[163]]as the frosts of winter have not arrived these open galleries are trodden by Spiders and other plunderers, for whom the eggs would make an agreeable meal.
The better to observe them, I placed a number of the eggs in boxes; and when they hatched out about the end of September I imagined they would at once start off in search of an Anthophora-cell. I was entirely wrong. The young grubs—little black creatures no more than the twenty-fifth of an inch long—did not move away, though provided with vigorous legs. They remained higgledy-piggledy, mixed up with the skins of the eggs whence they came. In vain I placed within their reach lumps of earth containing open Bee-cells: nothing would tempt them to move. If I forcibly removed a few from the common heap they at once hurried back to it in order to hide themselves among the rest.
At last, to assure myself that the Sitaris-grubs, in the free state, do not disperse after they are hatched, I went in the winter to Carpentras and inspected the banks inhabited by the Anthophoræ. There, as in my boxes, I found the grubs all piled up in heaps, all mixed up with the skins of the eggs.
I was no nearer answering the question: how does the Sitaris get into the Bees’ cells, and into a shell that does not belong to it? [[164]]
II
THE FIRST ADVENTURE
The appearance of the young Sitaris showed me at once that its habits must be peculiar. It could not, I saw, be called on to move on an ordinary surface. The spot where this larva has to live evidently exposes it to the risk of many dangerous falls, since, in order to prevent them, it is equipped with a pair of powerful mandibles, curved and sharp; robust legs which end in a long and very mobile claw; a variety of bristles and probes; and a couple of strong spikes with sharp, hard points—an elaborate mechanism, like a sort of ploughshare, capable of biting into the most highly polished surface. Nor is this all. It is further provided with a sticky liquid, sufficiently adhesive to hold it in position without the help of other appliances. In vain I racked my brains to guess what the substance might be, so shifting, so uncertain, and so perilous, which the young Sitaris is destined to inhabit. I waited with eager impatience for the return of the warm weather.