Medical and Veterinary Importance of Lice

Medical and veterinary importance of lice Prepared by Abdallah M. Samy Entomology Department Faculty of Science Ain Shams University

Lice O: Phthiraptera (sucking and Chewing lice)

Sucking lice F1:Pediculidae

F2: Haematopinidae

Chewing lice

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 stages live permanently on humans “ permanent ectoparasite”, clinging mainly to hairs of their clothing and usually only to body hairs during feeding.
Both sexes, as well as immatures, take blood-meals at any time of day or night.
Females lay their eggs on clothes fibers/ hairs.
Lice have 3 nymphal instars.
The third nymphal instar is then develop 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:  Louse-borne epidemic typhus  Trench fever  Louse-borne epidemic relapsing fever

F2: Haematopinidae Haematopinus tuberculatus (Cattle louse) A parasite of the water buffalo; it also infests domestic cattle when in association with water buffaloes. It causes irritation to 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 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.