LEAF-BEETLE. Any one of a large family of beetles, the Chrysomelidte. so called because both adults and larva• feed on the leaves of plants. The family is an enormous one, as it comprises about 18,000 species. The great ma jority are found in the tropics, but 000 species occur in North America. The leaf-beetles are nearly all small, the potato-beetle being one of the largest of the family. The eggs, as a rule, are laid on the food plant. The of many spe cies live on the leaves, either exposed or covered with grass. Some carry perfectly constructed eases: others are leaf-miners, as the Hispini; still others are root-horers and stem-borers. and a few are aquatic—a remarkable diversity of habit in the of a single family. The cover with The most remark able covering formed by any insect, perhaps, is that made by a tropical American leaf-beetle of the genus Porphyraspis, •hieh lives on eocoa palms at Bahia. The are covered by it sort of bird's-nest-like coating of fibres or threads attached to the anal extreunity, which are fibres that have passed through the alimentary canal and have been stuck together again. Some of the tropical species of this group are extreme ly beautiful and mounted in gold are used as jewelry. With the species of temperate regions
the color usually fades and becomes sordid after death. Among well-known destruetive leaf beetles are those of the genus Crioeeris (see ASPARAGUS N SECTS ) the potato-beetle, and the cueumber-beetle, and its allies of the genus Diabrotica. In California the adults injure fruit and fruit-trees, and in the East they eat the leaves of cucumber, squash. and melon vines, and the young bore into the stems and roots of the same and other food plants. (See CORN-INSECTS.) All the Diabroticas are diffi cult insects to combat. Another group of agri cultural pests in this family is that of the flea beetles (q.v.). The brown and black larva' of the grapevine flea-beetie feed on the supper sur face of grape-leaves. A well-known and destruc tive species is the imported elm-leaf beetle. (See ELM-INSECTS.) On the sweet-potato and morn ing-glory vines small, flattened, beautifully iri descent leaf-beetles occur, which are gold and green. (See GOLDEN IIEE•L•.) Consult : Dim mock, Standard Natural History, vol. ii. (Bos ton. 1884) : Sharp, Cambridge Natural Tlistory, voi. vi. (London, 1899).