467. The family of Sawflies is quite an extensive aberrant family. They are so called from a curious double saw in the ovipositor, with which they make holes in the branches and other parts of trees for the deposit of their eggs. Carpenter mentions one species in England, whose larvæ are very destructive to turnips, devastating a whole field in a few days by devouring the soft tissue of the leaves; and he states that the most effectual remedy has been found to be the introduction of ducks into the fields, as they very greedily devour the larvæ. 468. Of the Aculeate division of the Hymenoptera we make two subdivisions-the Predaceous, or those which live on prey, and the Melliferous, or honey-collecting stingers. 469. There is one group of the Predaceous division, including several families, which may be called, from their peculiar habits, diggers. They are known commonly as Sand and Wood Wasps. They are solitary-that is, do not live in communities. They therefore are all males and females, and have no neuters or workers. The females commonly dig out cells in the ground, or in posts and timbers. In these they deposit with their eggs insects which they have killed, so that the larvæ, when hatched, may have something to live upon. Sometimes the insects thus deposited are only stung sufficiently to render them powerless. Decomposition is thus prevented, and the larvæ, when they come forth from the eggs, kill the insects and devour them. The perfect insects are active in their habits, flying about and running over sand-banks with their wings in constant motion. They are fond of the nectar of flowers, a very different food from that which they devour in the greedy larva state. Those which are sand-burrowers have strong brushes on their legs with which they excavate their nests, while the wood-burrowers have powerful mandibles with toothlike projections, which convert the wood into sawdust in making the burrow. 470. The Mud-wasp, Fig. 213, is one of the sand-bur Fig. 213.-The Mud-wasp. ging after mice, throwing the earth rowers. The following is the account given of it by Jaeger. "This insect is more than an inch long, and of a dark bluepurple color. It makes its abode in the loose, sandy ground, and when digging its hole re sembles a dog digunder it toward its hind body with its fore feet. If the pile of sand becomes too high or troublesome, it places itself upon it, and throws the earth behind it with great force until it is leveled. As soon as its subterranean abode is prepared, it seizes a large Spider, or a caterpillar, or some other insect, stings it in the neck, and then carries it into its hole. It is curious to see one of these Wasps take hold of a Cockroach, seizing it by one of its long antennæ, and continually walking backward, compelling the Cockroach to follow, notwithstanding its great reluctance and constant opposition, until both have arrived at the hole, where the Wasp kills it by a sting in the neck, then tears into pieces, and carries it into her subterranean dwelling as food for her offspring." 471. The family of Vespidæ, or true Wasps, is distinguished from the other Hymenoptera by the folding of the wings when at rest throughout their entire length. They are generally not solitary, but social, the communities, however, being small. The neuters are not, like the neuters of the Ant tribe, destitute of wings. Those Wasps which are solitary have no neuters, and their habits are like the diggers just noticed. There are many species of the Social Wasps, the best known of which, as the common Wasp, build their nests of a stout brown paper, which they manufacture from bits of wood and bark. Like the paper-maker among men, they reduce their material to a pulp, and then spread it out thinly, which, drying speedily, becomes firm paper. In Fig. 214 you see the arrangement of the nest of the Social a Fig. 214. Wasps. Each floor of cells hangs from the floor above it by rods. At a a is the outer wall, made of many layers of brown paper; at b and c are five terraces of cells for the neuter Wasps; and at d and e are three rows of larger cells for the males and females. In Fig. 215 is a representation of a portion of one of these terraces, with its rod. Fig. 215. 472. The family Formicidæ, or Ants, are placed in a different order from the White Ants, § 453, on account of the difference in the wings, those of the latter having the characteristic network of the Neuroptera. They are distinguished from all the other families of the Hymenoptera by their residing under ground in large societies, some of them raising the earth up in mounds in constructing their habitations. The males and females, which alone are winged, constitute but a small portion of each community, most of it consisting of wingless neuters or laborers. The different parts of the nest are very curiously and regularly arranged. The males and females leave the nest as soon as they have wings. The males die, and of the females some return and deposit their eggs in their original nest, while others go to a distance and found other colonies. When they begin to lay their eggs, as their destiny is now to stay in one place, they have no farther need of wings, and therefore strip off themselves the useless encumbrances, or allow them to be stripped off by the neuters. These last not only construct the nest, but take care of the eggs, and also of the grubs that are hatched from them, feeding them, and carrying them on clear warm days to the outer surface of the nest, and taking them back again when night approaches, or before that if there be a threatening of bad weather. Ants are very fond of saccharine matter, and accordingly are apt to find out where it is. They are also fond of some fruits. I have been amused to see how any pear in my garden, that chances, in falling, to have a breach made in the skin, is at once beset with Ants, who quite rapidly eat out the inside. 473. In most cases a community of Ants consists only of three kinds of individuals-males, females, and neuters. But in some of the species some of the neuters are larger than the rest, and differently shaped, and appear to be the soldiers of the community, whose duties are the same with those of the soldiers among the Termites (§ 455). There are wars, sometimes, between different |