in zoology: A genus of insects of the neuroptera order; the characters of which are... Hemerocall these. The mouth is furnished with two teeth; the palpi are four; the wings are deflected, but not plaited; and the antennae are brittle, and longer than the breast.

There are 15 species, principally distinguished by their colours.—This insect takes the name of hemerobius from the shortness of its life, which, however, continues several days. In the state of larva it is a great devourer of plant-lice, for which it has had bestowed upon it the appellation of lion of the plant-lice. The hemerobii, even after their transformation, preserve their carnivorous inclination. Not satisfied with making war upon the plant-lice, who tamely let themselves be devoured, they do not spare each other. The eggs of this insect are borne upon small pedicles, which are nothing but a gum spun out by the hemerobius by raising up the hinder part of its abdomen, and by that means the egg remains fastened to the upper part of the thread. Those eggs are deposited upon leaves, and set in the form of bunches. They have been taken for parasitic plants. The larva, when hatched, finds there its food in the midst of plant-lice. In 15 or 16 days it has attained to its full growth. With its spinning wheel at its tail, it makes itself a small, round, white, silky cocoon, of a close texture. In summer, at the end of three weeks, the hemerobius issues forth with its wings; but when the cocoon has not been spun till autumn, the chrysalis remains in it the whole winter, and does not undergo its final metamorphosis till the ensuing spring. The flight of this insect is heavy; some species have an excrementitious smell. One goes by the name of the water-hemerobius, because it lives mostly at the water side.