National Geographic : 1937 Jul
POTENT PERSONALITIES-WASPS AND HORNETS One would think that a hornets' nest would be free from intruders. But this is not the case. The existence of a worker caste which feeds the queen provides a new temptation for lazy and unscrupulous rela tives. Slavery appears. Perhaps slavery is too harsh a term. Let us say that certain unethical young ladies succeed in adopting for their own benefit the swarms of worker nursemaids attendant upon a matron more advanced in age. As an example of such conduct, take a small hornet that lives whopy at the ex pense-and to the detriment-of the little yellow jackets, whose nests are all too com mon in our fields in summer. This lazy, sponging relative, Vespula arc tica (Plate V, figure 5) has no worker caste - only males and fertile females. The over wintering females probably appear later in the spring than the female yellow jackets, emerging from hibernation after the latter's nests have been established. Entering the yellow jackets' nests, they induce, or force, the yellow-jacket workers to raise their progeny instead of the young of the rightful queen, their mother. Both the intruder and the true queen may live in the nest together, or the intruder may be found alone. I do not like to appear unsympathetic, but it is difficult to suppress a feeling of admiration for an insect so very clever and persuasive as to be able to make nursemaids for its babies out of a nestful of yellow jackets! Besides their lazy relatives, hornets have other sorts of enemies. Among these is a puny little ichneumon fly, Sphecophaga burra (Plate V, upper, extreme right), the young of which live within the bodies of their grubs, including those of the for midable white-faced hornet. PAPER WASPS CHIRP AS THEY WORK As familiar as the hornets are the com mon paper wasps, of several different kinds, that build their combs exposed, without any protecting envelope, usually in sheltered sit uations and commonly about houses (Plate V, lower, and page 66). In contrast to the hornets, the workers of these paper wasps scarcely differ from the queens. If you observe them carefully you will notice that they have a way of chirping cheerfully while at work. This is also true of many, if not most, other wasps. The plate shows a portion of the privet hedge outside my office window. Mr. Murayama and I spent some time watching the wasps hawking back and forth along the hedge and in and out among the branches, searching for insects. Our native paper wasps are unaggressive, and their nests are usually placed where there is no danger of hitting them. So they are not likely to sting you. Hence they are much less unpopular than hornets. FLOOD CONTROL AND AIR CONDITIONING Interesting creatures are these paper wasps. For instance, flood control is one of their specialties. When a nest is built so that it is exposed to the weather it is naturally likely to get wet. Undaunted, the wasps lap up the water and then re gurgitate it away from the nest. Mr. Phil Rau has discovered a still more remarkable fact. In times of drought the workers bring water and drench the nest, in this way cooling it and providing needed moisture for the young. Air-conditioned nurseries, therefore, are no new invention. Paper wasps used windows untold cen turies before man ever thought of them. Some tropical kinds under certain conditions insert in the outer covering of the nest small transparent specks, apparently of mica, up to an eighth of an inch across. These are evenly distributed over the paper sheet, each one being framed in a mouthful of pulp. Mr. Rau found one nest with approxi mately one-third of the surface translucent, and another with about half the surface made up of these particles. MY FRIENDS THE HALICTUS Like the burrowing wasps, many of the daintiest and prettiest of our smaller bees are true children of the soil. One of these, Halictus pruinosus, is a special friend of mine, for I have a little village of them right in my front yard. Here in bare spots in the grass comical little faces peer at you. Each face serves as a stopper for a burrow in which resides a growing family of bees (Plate VII, upper). These pretty bees are very satisfactory neighbors. Though many times, in weed ing and other operations, I fear I have treated them most thoughtlessly, they have never stung me. They are suspicious little creatures and always keep a guard, usually a male, whose face almost completely fills the doorway.