laying process for 30 days. Except when taking blood meals, the adult louse remains in
the person's clothing.
b. The Head Louse. The head louse (Pediculus humanus capitis) closely
resembles the body louse but unlike the body louse, is unimportant as a vector of
This pest is generally confined to the human scalp and head hair.
The female cements her eggs to the hair, especially in the area above
and behind the ears and towards the nape of the neck.
The life cycle is similar to that described above for the body louse,
although the head louse tends to be smaller and lays fewer eggs, and generally remains
on the host throughout the life cycle.
Figure 5-19. Lice of medical importance.
c. The Crab Louse. The crab louse (Phthirus pubis), readily recognized by its
crab-like appearance, is probably of no importance in disease transmission, but it is of
military importance as an annoying pest and as an indicator of the state of personal
hygiene in a unit.
Crab lice frequently are acquired during sexual contact with an infested