Bees.—See [Domesticated Animals].
Bumble-bees.—These common bees are large, somewhat clumsy-looking insects which live in communities including workers or imperfect females as well as ordinary members of the two sexes. The nests are constructed in holes in the ground or other sheltered places, and the establishment of a community is due in the first instance to the labors of a queen in early summer. She makes a number of waxen cells, stores them with honey and pollen, and afterwards feeds the larvæ when they have devoured these provisions. From the first (and several other), batches of larvæ workers are chiefly produced, which undertake the constructive and nursing work, until at last the queen has nothing to do but lay eggs. Males and other queens are reared from some of the eggs laid in late summer and early autumn.
Wasps, like bees, are either solitary or social, and it is only in the latter that workers exist. Solitary wasps construct small nests of clay and little stones, or else make burrows. They possess the curious habit of storing up immature—for example, caterpillars—or mature insects, or even spiders, for the benefit of their larvæ when these hatch out. The kind of victim depends upon the species of the wasp concerned, but in any case it is killed or paralysed by stinging.
Social wasps somewhat resemble social bees in their habits, but their building material, instead of being wax, is a kind of paper made of chewed wood mixed up with saliva. In some instances the nest is suspended from a bush or tree, and is provided with a kind of overhanging roof by which rain is drained off.
In our commonest species, an underground site is chosen, and a series of combs constructed from above downward, the whole being enclosed in several layers of wasp paper. Adjacent combs are held together by little pillars. The young are at first fed upon fruit-juice, nectar, and other vegetable matter, for which a more stimulating diet of chewed insects is afterwards substituted.
The Hornet (Vespa crabro) is a social wasp which commonly nests in hollow trees or constructs elaborate nests out of wood fibers, suspended from boughs. The females have formidable retractile stings. The hornet is represented in the United States by the white-faced hornet (V. maculata), also a large species.
FLIES (Diptera)
There are some thirty or forty thousand species of flies known, while no other order has so many individuals as this. This enormous assemblage of insects, most of which are small or even minute, includes many species that have earned an undesirable reputation as bloodsuckers and pests. Except in fleas and a few others, such as sheep-ticks, there are two membraneous front wings, the hinder pair serving as sensory structures. The mouthparts of the female are very often piercing and sucking organs of great efficiency, the first and second jaws being in the form of slender lancets protected above and below by the upper and under lip respectively.
But in other types, such as the house-fly (Musca domestica), the jaws are modified into a proboscis used for sucking juices, and devoid of powers of perforation.
THEIR UNCLEANLY AND DEATH-
CARRYING HABITS