Ventral View of a Male Body Louse (Pediculus humanus var. corporis)

This photograph depicts a ventral view of a male body louse, Pediculus humanus var. corporis. Some of the external morphologic features displayed by members of the genus Pediculus include an elongated abdominal region without any processes, and three pairs of legs, all equal in length and width. The distal tip of the male’s abdomen is rounded, whereas, the female’s is concave.

Body lice are parasitic insects that live on the body, and in the clothing or bedding of infested humans. Infestation is common, found worldwide, and affects people of all races. The dark mass inside the abdomen is a previously ingested blood meal, obtained by the louse when the photographer offered his arm to the insect on which it fed.

How is a body lice infestation diagnosed?

By looking closely in the seams of clothing and on the body for eggs and for crawling lice. Diagnosis should be made by a health care provider if you are unsure about infestation.