CHIGGERS

The name chigger originated as a corruption of chigoe. Also called scrub mite, red mite and several other names, they are found throughout temperate and tropical zones. Chiggers come in 3 stages: the deutovum, unfed larva, and engorged larva. Once in the egg developing, the larvae enclosed in a membrane in addition to the eggshell, are called deutovum. After hatching, the unfed larvae migrate to the highest area and wait for a host to feed on.

The larval stage is the only parasitic stage of the mite’s life cycle. They are parasites to many animals. About 30 of the many species in this family, in their larval stage, attach to various animals, including amphibians, reptiles, birds, and mammals, and feed on skin. This often causes an intensely itchy red bump in humans (who are accidental hosts).

Chiggers attach to the host, pierce the skin, inject enzymes into the bite wound that digest cellular contents, and then suck up the digested goodies through a tube formed by hardened skin cells called a stylostome. They do not burrow into the skin or suck blood, as is commonly assumed. Itching from a chigger bite may not develop until 24–48 hours after the bite, so the victim may not associate the specific exposure with the bite itself. The red welt/bump on the skin is not where a chigger laid eggs, as is sometimes believed. The larva remains attached to a suitable host for 3 to 5 days before dropping off to begin its nymph stage.

Chiggers do not like sunlight or humidity. Note, however, that there appears to be some disagreement here, since many other authorities state that chiggers thrive in and need high humidity. During the wet season, chiggers are usually found in tall grass and other vegetation. During dry seasons, chiggers are mostly found underneath brush and shady areas.

They are most numerous in early summer when grass, weeds and other vegetation are heaviest. In their larval stage they attach to various animals, including humans, and feed on skin, often causing itching. These relatives of ticks are nearly microscopic.