PHILANTHUS PUNCTATUS
On August thirteenth, at half after eight in the morning, we found that a second female, perhaps inspired by the example of her sister, had made a new nest within two inches of the first one, and had flown away, leaving it open. Presently the other wasps began to appear, one after the other, in their doorway. Two of the males flew away, and one of the females, doubtless the one that we had seen digging the night before, began to work afresh at making the nest larger. Probably she was excavating a pocket for the reception of an egg, and the amount of labor required was enormously increased by the great length (about twenty-two inches) of the main gallery by which the displaced earth must be carried out. She worked for an hour, and in spreading the dirt about, inadvertently filled in the opening of the second nest. At length she flew away.
At ten o’clock a female arrived carrying a bee, and tried to find nest No. 2. She came to the wrong place, and worked about, here and there, for some minutes, holding the bee under the thorax, clasped by the second pair of legs. Being unsuccessful, she dropped her burden, and flew away for a few minutes. While she was gone we removed a leaf that had fallen over her nest, and on her return she at once descended upon the right spot, and began to scratch open the entrance, the bee being kicked backward with the rejected earth. When the way was clear, however, she picked it up, brought it toward the hole, dropped it, ran in and out, brought it nearer, ran in again, and turning around in the tunnel, seized the bee in her mandibles and pulled it down. This performance was due to the accidental obstruction of the gallery, for we afterward found that punctatus ordinarily flies directly into her nest, or, when it is closed, pauses on the wing to scratch an opening with the first legs. The bee is pushed backward a little as she goes in, but does not often project from under her abdomen.
At fifteen minutes after ten the worker from nest No. 1 brought in a bee, and from that time the two worked industriously. They showed some individuality in their ways, for No. 2 always closed her door when she went away, and never circled at all, while No. 1 invariably circled before leaving, and always left her nest open. To be sure, there was a female left on guard, so that perhaps she did not feel the need of caution.
Our wasps had not far to go for their victims. Forty feet away, on the eastern side of the island, was a steep declivity, and here, in the soft crumbly soil, was a great Halictus settlement. No prettier sight can be imagined than is presented by this colony on every sunny summer day. The whole bank is riddled with nests, and at the entrance of each stands a female bee, her tiny head exactly filling the opening. The bees are constantly arriving, laden with pollen, whereupon the sentinels politely back inward to make way for them. Into this scene of contented industry descends the ravaging Philanthus, taking guards and workers alike.
On the afternoon of the fourteenth of August our two wasps were in the full tide of affairs. No. 1 took in eleven bees within two hours, but her record was somewhat confused, as two other females were going in and out at the same time. We felt sure that neither of these was hunting, but one of them shared in the labor of the nest by helping with the work of excavation.
No. 2, however, was alone, so that we could keep a definite account of her comings and goings. We watched her from half past one until five, at which hour she came home without a load, and at once closed the nest for the night, after having stored thirteen bees in three hours and nine minutes. In some cases the capture of the bee occupied only one, two, or three minutes, while at other times she was gone much longer. At each return she stayed only an instant—just long enough to deposit the bee—inside the nest, and then spent a minute in carefully closing the hole. The wasps that were going in and out of nest No. 1 sometimes closed it when they went away, but this was done in an untidy fashion, quite different from the nicety and precision of No. 2.