Wasps, Social and Solitary

by George W. Peckham; E. G. Peckham

On the eighth of July the weather was so warm and bright that we went down to the garden at half past eight o’clock, knowing that it was rather early, but hoping that the hot sunshine would tempt the wasps to industry. We had walked up and down several times, when suddenly, right in the pathway, a nest appeared. A great quantity of loose earth had been taken out and heaped up, probably on the preceding day, and in the midst of this a little hole had been opened since we passed before. The place looked so promising that we sat down to watch it, and a few minutes later we were rewarded by a glimpse of some antennæ down the gallery, and then a little face with yellow markings appeared but quickly vanished. Now followed a very coquettish performance. The wasp came slowly creeping up again and again, only to drop out of sight as soon as she had reached the opening. After a time she grew bolder, and sat in her doorway, twitching her head this way and that in a very expressive manner, as though she were planning the work of the day; but it was plain that although she was up early, business cares were not weighing heavily upon her mind, for forty minutes passed before she came out of the nest, and after making three or four circles about the spot, flew away.

How much livelier and more interesting it would have been if we could have followed her! We tried to guess at what she was doing, and imagined her hunting industriously. After fifteen or twenty minutes it seemed to us that she must have caught something, and that she was surely returning. Most probably she was not working at all, but was breakfasting leisurely and exchanging compliments with her neighbors; for when she did come home after keeping us waiting for an hour and a half, she brought nothing with her, and seemed quite unconscious of the fact that greater things had been expected of her.

We had placed a stone upon a dead leaf near by, to mark the neighborhood of the nest, thinking that even a Cerceris could not object to so simple an arrangement of natural objects; but our wasp noticed it at once, and evidently with much suspicion and disapproval. She began by circling several times just above it. Then she alighted on it and examined it carefully, walking over it, and creeping underneath, perhaps to see whether it in any way menaced the safety of her nest, perhaps as the completion of a locality study made the day before. She then rose on her wings, and after a little more circling, dropped suddenly into her hole.

So far we had not been getting on very rapidly, but from this time things took a turn. Cerceris is never in a hurry, and yet she may be relied upon to do a certain amount of work every day. The one that we were now watching had probably come back for a final look at her newly made nest before beginning to provision it; for she soon reappeared, and this time really went to work, since in forty minutes she brought home a beetle which she carried by the snout, venter up, in her mandibles, supporting it with the second pair of legs while flying. She was much annoyed at our presence, and circled about as before. Twice she alighted near by, and walked around for a few minutes, and when she did this all her feet came down to the ground, the beetle being allowed to hang loosely. At last she made the best of a bad matter, and went in. The rest of the morning was occupied with hunting, the capture of each beetle taking about forty-five minutes. Every time that she came home she spent fifteen or twenty minutes in the nest.

This species soon became very common, and for two weeks scarcely a morning passed without our finding at least one newly-made nest. The study of clypeata, however, consumes a great deal of time. For example, we found, one morning, two nests within six inches of each other. It turned out afterward that these were inhabited by two different wasps; but at the moment we supposed that one of them had been dug and deserted and then a second one made, and wishing to know which one was occupied we resolved to watch and see. After waiting for three hours we saw one wasp returning; but upon noticing us she veered off and began to circle about. She was heavily laden, and her burden, instead of being supported by the second pair of legs, as is sometimes the case, hung down under the thorax and abdomen. After a moment she alighted on a plant near by, and seemed to consider the situation, then circled a little more, and flew away, remaining out of sight for fifteen minutes, then another return, more circlings and hesitations. She seemed to feel the weight of the beetle now, and alighted frequently on the ground and walked about; yet she would not go in, so reluctant was she to betray her nest. In this way she kept us waiting for a whole hour, although we were not very near to her, and were as still as statues. At last we retreated, and stood as far back as we could and still keep the hole in view. She now came closer, and, after hanging poised on her wings for a moment, dropped into her nest.

We once found a nest of this species in process of construction. A large heap of fresh earth had been pushed out, which entirely covered the spot; but at intervals there were upheavals from below which betrayed the presence of the wasp. When we saw it first it was half past eight o’clock, and we judged, from what had been accomplished, that she must have been at work at least an hour. It was half past nine before the excavation was complete. We had not been certain, up to this time, as to what we were watching; but now we had the pleasure of seeing her open her doorway from below and stand in the entrance while she washed her face with her fore feet, like a cat. When they rest at the mouth of the hole the first legs, which are yellow, are bowed in a semicircle on each side of the yellow face, the distal joints being bent up so that the wasps seem to be standing on their elbows. This attitude, which is often seen in Bembex spinolæ, gives them a delightfully amusing, bow-legged appearance. They usually open their nests in the morning at about nine o’clock,—a little earlier or later according to the time at which the sun strikes the spot. Then they spend from forty minutes to an hour in taking a survey, the least movement on the part of a watcher causing them to drop out of sight as if the earth had given way beneath them. Sometimes there is a little way-station an inch or two within the tunnel, and the wasp falls back only to this point, and here she may be seen, if one peeps in cautiously, either quietly awaiting the retreat of the intruder, or, perhaps, performing her toilet in a leisurely and elegant manner.

Whenever she leaves her nest she makes three or four rapid circles around the spot to freshen her memory of the locality. The most thorough study that we saw made by clypeata was in the case of the wasp mentioned before, that was so long in carrying her beetle in because of our being on the ground. When she finally did go in she stayed only an instant—just long enough to deposit her load—and then came out and spent a long time in an investigation of all the surrounding objects, flying in and out among the plants, now high, now low, and circling again and again around the spot. It looked as though she had been puzzled and disturbed by the presence of unaccustomed things. As soon as the survey was over she went inside and closed the door, as though its object had been not so much to strengthen her memory as to correct former impressions.

The work of bringing in beetles goes on very irregularly, and as a rule not more than two or three are stored in the course of a day. It is not unusual for clypeata to spend three or four hours away from home and then come back without anything; and often, even in the middle of the day, she passes an hour or two in the seclusion of her nest. We had several nests under observation for a week at a time without ever once seeing the owners, although they were evidently occupied, since they were sometimes open and sometimes closed. The outer entrance is always left open when the wasp goes away, although possibly access to the pockets may be barred below; but when she enters she closes the door unless she means to come out again at once. The closing is sometimes effected by pushing the earth up backwards, with the end of the abdomen; but the hole is rather too large for this method, and more frequently the wasp comes up head first, carrying a load of earth in her front legs. This is placed just within and to one side of the entrance, and then more armfuls are brought up, until, after two or three trips, the opening is entirely filled.

We once captured the wasp in a bottle, as she returned, loaded, to the nest. She dropped the beetle, but soon picked it up again and stung it vigorously, with intention, as the French say, first under the neck, and then further back, behind the first pair of legs. After this it was dropped while the wasp fluttered about for a few minutes, but it was then picked up again, and stung as before. We both saw this operation repeated in exactly the same way, four different times, with intervals of five or six minutes between.

In a nest which we excavated after watching it for nine days, we found nothing until we had gone six inches down, and at this point the tunnel was lost; but mixed with the crumbly earth that we took out of the hole, we found eight beetles and a half-grown larva of clypeata. The destruction of this nest was accomplished one morning, and when we came back to the spot twenty-four hours later we found that a new one had been made close by, doubtless by the same individual. We had expected to find her bringing beetles and dropping them foolishly on the ground like Paul Marchal’s Cerceris ornata, and were gratified that she showed an advance in intelligence over that species, although to be sure she would have been still wiser had she chosen an entirely new neighborhood. Another individual was so much disturbed by our scrutiny that she dropped her beetle at the entrance to her nest. She did not pick it up again and utilize it, although it lay for three days in the dust at the threshold.