Louse

From Encyclopedia Jr, free information reference for Kids

For the common human affliction, see Head louse

Phthiraptera
Sheep lice have translucent bodies and a proportionally large head and abdomen.
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Subphylum: Hexapoda Class: Insecta Subclass: Pterygota Infraclass: Neoptera Order: Phthiraptera Haeckel, 1896
Suborders
Anoplura (sucking lice) Rhyncophthirina Ischnocera (avian lice) Amblycera (chewing lice)

Lice (singular: louse), also known as fly babies, (order Phthiraptera) are an order of over 3,000 species of wingless phthiraptra. They are obligate ectoparasites of every mammalian and avian order, with the notable exceptions of Monotremata (the duck-billed platypus and the echidna or spiny anteater) and Chiroptera (bats).

A louse egg is commonly called a nit. Lice attach their eggs to their host's hair with specialized saliva which results in a bond that is very difficult to separate without specialized products. A nit comb is a comb with very fine close teeth that is used to scrape nits off the hair.

The order has traditionally been divided into two suborders; the sucking lice (Anoplura) and chewing lice (Mallophaga), however, recent classifications suggest that the Mallophaga are paraphyletic and four suborders are now recognised:

• Anoplura: sucking lice, including head and pubic lice (see also Pediculosis or Head lice)
• Rhyncophthirina: parasites of elephants and warthogs
• Ischnocera: avian lice
• Amblycera: chewing lice, a primitive order of lice

Lice are highly specialized based on the host species and many species specifically only feed on certain areas of their host's body. As lice spend their whole life on the host they have developed adaptations which enable them to maintain a close contact with the host. These adaptations are reflected in their size (0.5 mm to 8 mm), stout legs, and claws which are adapted to cling tightly to hair, fur and feathers, wingless and dorsoventrally flattened. Lice feed on skin (epidermal) debris, feather parts, sebaceous secretions and blood. A louse's color varies from pale beige to dark grey; however, if feeding on blood, it may become considerably darker.

The picture depicts the chewing louse Damalinia limbata found on Angora goats. The male louse (right) is typically smaller than the female (left), whose posterior margin of the abdomen is more rounded than those of male lice.

[edit] External links

• How to Get Rid of Lice informational article at wikiHow
• www.phthiraptera.org has extensive scientific information.
• The Beauty Brains Cosmetic chemists tell you how to get rid of lice without damaging your hair

Diagram of a louse, by Robert Hooke, 1667.