Medical and veterinary

importance of lice

Prepared by

Abdallah M. SamyAbdallah M. Samy

Entomology Department

Faculty of Science

Ain Shams University

LiceO: Phthiraptera

(sucking and Chewing lice)

Sucking lice Chewing lice

F1:Pediculidae

F2: Haematopinidae

F3: Philopteridae

F4:Menoponidae

F1:Pediculidae

e.g. Pediculus h. humanus (body louse)

�Dorso-ventrally flattened.

� Clinging legs

� Wingless.

� pale beige or grayish in color in color.

e.g. Pediculus h. capitis (Head louse)

�Dorso-ventrally flattened.

� Clinging legs

� Wingless.

� Dark in color with;

� Festoons-like structures laterally on its body.

Lice life cycle

�Both adult and immature stageslive permanently on humans “permanent ectoparasite”, clingingmainly to hairs of their clothing andusually only to body hairs duringfeeding.

� Both sexes, as well as� Both sexes, as well asimmatures, take blood-meals atany time of day or night.

� Females lay their eggs on clothesfibers/ hairs.

� Lice have 3 nymphal instars.

� The third nymphal instar is thendevelop to adult

Medical importance of Lice

�Pediculosis: an infestation of lice -- which are

parasitic insects -- on the bodies of humans.

� Lice as a vector for diseases:� Lice as a vector for diseases:

� Louse-borne epidemic typhus

� Trench fever

� Louse-borne epidemic relapsing fever

F2: Haematopinidae

Haematopinus tuberculatus(Cattle louse)

A parasite of the waterA parasite of the waterbuffalo; it also infestsdomestic cattle when inassociation with waterbuffaloes. It causes irritationto the infested animal.

Copyright to MCP, 1998

Chewing Lice

Family3:Philopteridae

Lipeurus caponis�They are permanent ectoparasites on birds, where they

feed on sloughed epidermal tissues, feathers and

sebaceous secretions of the host.

�Parts of feathers, particularly the barbs and barbules

constitute a major part of the food of this louse.

�The irritation louse feeding causes the host to become

restless, therefore affecting its feeding, habits and

digestion. Egg production is greatly reduced and

development retarded.

� Lice tend to be abundant where uncleanliness and

overcrowded conditions exists.

�Generally chewing lice act as intermediate hosts to the

tapeworms Dipylidium caninum as it is easy for lice to

become infected by swallowing worm egg capsules.

F4: Menoponidae

Menopon gallina

Biting and annoyance

Chewing lice don't attack man but

several species are importantseveral species are important

pests of domestic animals,

especially poultry; they feed on

feathers or hairs of the host, may

cause considerable losses in the

wool, meat, and diary production.