Head Lice Life Cycle

Head Lice Life Cycle

Head Lice Life Cycle

The Head Lice Life (Pediculus humanus capitis) Cycle consist of 3 stages i.e Eggs/Nits, Nymphs and Adult Head Lice. All these 3 stages last in about 40 to 50 days.

Eggs/Nits

Head Lice reproduce by laying eggs/nits on the hair shaft close to the scalp of their host. The adult female louse can lay up to 4-10 eggs a day and about 120 eggs in the whole lifespan. The dark-brown color eggs are oval-shaped and about 0.8 mm in length. The eggs hatch in about six to nine days, depending on temperature.

Head Lice Eggs/Nits

Head Louse Egg/Nit

Nymphs/Baby Lice

Newly hatched nymphs or baby lice feed on the blood of their host like adult lice and molt three times before reaching the sexually-mature adult stage. The nymphs look similar the adult head lice, but are smaller and have relatively pale color. The Nymph stage lasts about 9 to 12 days, depending on feeding conditions.

Head Lice Nymphs

Head Louse Nymph in Scalp

Adult vs Nymph Louse

Adult Head Lice

Adult head lice are about 1–3 mm long, tan to grayish-white in color. Head lice are wingless, have six legs, one pair of antenna, each with five segments and one pair of eyes. The abdomen consists of seven segments. Males are slightly smaller than females and having a pointed end of the abdomen. The females are characterized by two gonopods in the shape of a W at the end of their abdomen. The life span of an adult head louse is about 28 days.

Head Lice (Male and Female)

Female Head Louse

Male Head Louse