Wasps, Social and Solitary

by George W. Peckham; E. G. Peckham

On another morning we caught thirty-eight workers and took them to a boat-house on the shore of the lake, in the second story of which was a large room with two good-sized windows; one looked west over the lake and away from the nest, the other east toward the nest, and both were wide open. The west window was the brighter, but the other was light, the sun being on that side of the house.

We placed the cage in the middle of this room and opened the door, stationing ourselves well to one side so as not to interfere with the movements of the wasps. They came out very naturally, pausing a moment before flying, and followed each other so slowly that we could easily see which window they went out by. Twenty-two flew through the west window away from the nest, and sixteen through the east toward the nest.

At another time we took fourteen wasps from the nest of a different species and carried them seventy-three yards to the southeast. The cage was opened so that they could fly out in any direction they chose, and they all started in a straight line for the nest. Later on the same day, we took forty-five from this nest, and set them free one hundred and seventy-six yards to the south. Seven flew north toward the nest, twenty-one south, eight west, and seven east, while the other two circled around as they rose higher and higher, until they were lost to view. None in this experiment returned to take a fresh start.

Again, we took twenty-three wasps three hundred yards southeast of the nest and liberated them in an open field; thirteen flew east or south away from the nest, seven west or northwest toward the nest, and four returned to the starting-place and seemed unwilling to venture out again.

These observations show that the two species of wasps with which we experimented have no sense of direction in the form of a mysterious additional sense, nor yet in the form of a power by which they keep a register of the turns and changes in a journey and are thus able to retrace their way. Our cage was of wire, and so open that they could see all about, as we carried them from place to place; yet when they flew out, they most frequently started in a wrong direction and toward a point that we had not passed. In many instances, however, these wasps returned to the nest, and it seems highly probable that as they rose higher and higher into the air, circling as they went, they discovered some lofty treetop or other object that had before served them as a landmark, and that in this way they were able to make their way home. Bee-keepers know that if young workers which, in strong hives, pass the first ten or fifteen days of their lives in feeding the larvæ without going abroad, are taken out and set free only a short distance from home, they are unable to find their way back, and perish, while those that have passed beyond the nursing stage and have begun to do outside work may be carried long distances away and still readily regain the nest.

With the solitary wasps we attacked the problem from the other end. We observed what the social wasps did in attempting to return to the nest; with the solitaries, we watched them when, after making the nest, they prepared to leave it to go out into the fields or woods in search of food or prey, thinking that the procedure of different species under these circumstances would afford a clue to the faculty upon which they depended to find their way about. If they were furnished with an innate sense of direction they would not need to make a study of the locality of the nest in order to find the way back, but if they were without this sense it would be only common prudence to take a good account of their bearings before going far afield.

The sight of a bee or a wasp returning to its home from some far distant spot, without hesitation or uncertainty, is indeed marvelous. When we saw our first Ammophila perform this feat we were filled with wonder. How was it possible for her to hunt for hours, in all directions, far and wide, and then return in a direct line to a nest which had been so carefully covered over that every trace of its existence was obliterated?

To say that she is a creature of instinct, however, is not quite fair to her ladyship’s intelligence, as a better acquaintance with her would prove. In reading much popular natural history one might suppose that the insects seen flying about on a summer’s day were a part of some great throng which is ever moving onward, those that are here to-day being replaced by a new set on the morrow. Except during certain seasons the exact opposite of this is true. The flying things about us abide in the same locality and are the inhabitants of a fairly restricted area. The garden in which we worked was, to a large extent, the home of a limited number of certain species of wasps that had resided there from birth, or having found the place accidentally, had settled there permanently. To make this matter clear let us suppose the case of an individual of A. urnaria. In June she spent her time in sipping nectar from the onion flowers or from the sorrel that grew on the border of the garden. In July came the days of her courtship and honeymoon, and these too were passed in going from flower to flower, from one part of the garden to another. Many a day we have followed her when she flew from blossom to blossom along a row of bean plants, turning, when she reached the end, and wending her way leisurely back along the next row. Then comes a day when we see her running over the ground and looking carefully under the weeds for a good nesting-place. At last a spot is selected and she begins to dig; but two or three times before the work is completed she goes away for a short flight. When it is done, and covered over, she flies away, but returns again and again within the next few hours, to look at the spot and, perhaps, to make some little alteration in her arrangements. From this time on, until the caterpillars are stored and the egg laid, she visits her nest several times a day, so that she becomes perfectly familiar with the neighborhood, and it is not surprising, after all, that she is able to carry her prey from any point in her territory in a nearly direct line to her hole—we say nearly direct, for there was almost invariably some slight mistake in the direction which made a little looking about necessary before the exact spot was found.

After days passed in flying about the garden—going up Bean Street and down Onion Avenue, time and time again—one would think that any formal study of the precise locality of a nest might be omitted; but it was not so with our wasps. They made repeated and detailed studies of the surroundings of their nests. Moreover, when their prey was laid down for a moment on the way home, they felt the necessity of noting the place carefully before leaving it.