Page:Popular Science Monthly Volume 51.djvu/332

320 the hollows of trees and logs, which they occasionally clean out to render the places fit for their purposes.

Arthur Shipley, in describing some of the habits of the Vespidœ, has said in part that the workers among hornets "are females in which the ovary remains undeveloped; they resemble the perfect female in external appearance, but are slightly smaller. Unlike the bees', the wasps' community is annual, existing for one summer only. Most of the members die at the approach of autumn, but a few females which have been fertilized hibernate through the winter, sheltered under stones or hollow trees. In the spring and with the returning of warm weather the female regains her activity and emerges from her hiding place. She then sets about finding a convenient place for building a nest and establishing a new colony."

The methods of making the paper cells and their arrangement, the laying of the eggs in them, and the rearing of the young are practically much the same in both the common wasps and the social paper hornets. So Professor Shipley, after describing the manufacture of the paper nest of the common wasp (Vespa vulgaris)—how she lays a single egg at the bottom of each of the first three cells, and then this, the foundress of the society, "continues to add cells to the comb, and as soon as the grubs appear from the first-laid eggs she has in addition to tend and feed them."

"The grubs are apodal, thicker at the middle than at either end; the mandibles bear three teeth; the maxillæ and labium are represented by fleshy tubercles. The body, including the head, consists of fourteen segments, which bear lateral tubercles and spiracles. They have no arms. They are suspended with the head downward in the cells, and require a good deal of attention, being fed by their mother upon insects which are well chewed before they are given to the larvæ, or upon honey. At the same time the mother is enlarging and deepening the cells in which they live, building new cells and laying more eggs, which are usually suspended in the same angle of each cell. The development within the egg takes eight days.

"After about a fortnight the grubs cease to feed, and, forming a silky cover to their cells, become pupæ. This quiescent state lasts about ten days, at the end of which period they emerge as the imago or perfect insect. The silky covering of the cell is round or convex outward, and to leave the cell the insect either pushes it out, when it opens like a box lid, or gnaws a round hole through it. As soon as the cell is vacated it is cleaned out and another egg deposited. In this way two or three larvæ occupy successively the same cell during the summer. The first wasps that appear in a nest are neuters or workers, and these at once set to work to enlarge the comb and feed the larvæ, etc. . ..