From Big Medical Encyclopedia

LICE — insects of Mallophaga group, obligate ectoparasites of mammals (vlasoyeda) and birds (peroyeda).

The sizes P. vary from 0,5 to 11 mm; males usually more small than females. The body is flattened in the dorsoventral direction, coloring from pale yellow to almost black. Oral device of gnawing type. Wings are lost. Legs are often supplied with devices for fixing on hair or small beards of a feather. Morphologically and ecologically P. are very close to louses and Copeognatha. Eat epidermis, particles of a feather, allocations of the skin and blood acting from wounds and scratches. Items are strictly specialized on the owner and infect only close types; infection occurs at contact of owners, is more rare by means of the blood-sicking flies transferring larvae or adult forms P are (more rare).

A row biol, the devices providing their preservation and development in the conditions of the specific habitat is characteristic of P.: an attachment of eggs a strong secret to a feather or a hair, continuousness of reproduction, high intensity of development (3 — 4 weeks), ability to a parthenogenesis (see) etc.

Intensive infection of P. weakens animals, reduces their resistance to diseases. Besides, dog and cat's P. (Trichodectes canis, Felicola subrostrata) are intermediate owners of a tykvovidny tapeworm (Dipylidium caninum) — the parasite of dogs and cats sometimes meeting and at the person (it is preferential at children). Items serve as also intermediate owners of round and flat worms (see. Roundworms , Flat worms ).

Fight against P. consists in processing of animals insecticides (dusta, suspensions, ointments) and disinsections of livestock rooms.

See also Insects , Parasites .

Bibliography: Blagoveshchensk D. I. Opredelitel of lice (Mallophaga) of domestic animals, M. — L., 1940; To Lunkash M. I. Lice of poultry and measure of fight against them, Chisinau, 1978; Hopkins G. H. E. Notes on some Mallophaga from mammals, L., 1960.

C.H. Zarechnaya.