At a low magnification of 98x, this 2006 scanning electron micrograph (SEM) depicted a dorsal view of the head and left thorax of a male body louse, Pediculus humanus var. corporis. The entire left foreleg, or middle leg are not visible, but what is visible, includes each leg's coxa, trochanter, and femur, or the first, second, and third leg segments respectively. For a complete dorsal view of the louse's leg, see PHIL# 9228. The leg is composed of six segments: coxa, trochanter, femur, tibia, tarsus, and pretarsus or claw. In the case of the louse, the leg segments are very stout, and end in claws, which it used to firmly grasp clothing, or a host's hair shafts. Note how the exoskeletal covering appears to possess an added flexibility at the coxa-trochanteric joint.
CDC/ Joseph Strycharz, Ph.D.; Kyong Sup Yoon, Ph.D.; Frank Collins, Ph.D.
November 2, 2012