- Any one of numerous species of small, wingless, suctorial,
parasitic insects belonging to a tribe (Pediculina), now usually
regarded as degraded Hemiptera. To this group belong of the lice of man
and other mammals; as, the head louse of man (Pediculus capitis), the
body louse (P. vestimenti), and the crab louse (Phthirius pubis), and
many others. See Crab louse, Dog louse, Cattle louse, etc., under Crab,
Dog, etc. - Any one of numerous small mandibulate insects, mostly
parasitic on birds, and feeding on the feathers. They are known as
Mallophaga, or bird lice, though some occur on the hair of mammals.
They are usually regarded as degraded Pseudoneuroptera. See Mallophaga. - Any one of the numerous species of aphids, or plant lice.
See Aphid. - Any small crustacean parasitic on fishes. See Branchiura,
and Ichthvophthira.