Chiggers
Eutrombicula spp., primarily Eutrombicula alfreddugesi (Oudemans)
Trombiculidae, PROSTIGMATA


DESCRIPTION

Adult and Nymph -- Both stages are about 1.25 mm long, hairy, and usually brilliant red. Both the adult and nymph have four pairs of legs.

Egg -- The minute, globular egg is light colored at first, changing to a darker color with age.

Larva -- The hairy larva is about 0.16 mm in diameter and orange-yellow or light red in color. It has six legs.


BIOLOGY

Distribution -- Chiggers are worldwide pests. In North areas. Chiggers occur most frequently in berry patches, orchards, woodlands, pine straw, and along lake and stream margins.

Hosts -- Larval chiggers attach themselves to the skin of people, domestic animals, wild animals, poultry and birds. Nymphs and adults feed on insect eggs, small insects and decaying organic matter.

Damage -- Chiggers do not burrow into the skin as commonly believed. The larval stage firmly attaches to the skin. After feeding, the larvae dislodge and drop to the ground. An allergic reaction to saliva injected by larval chiggers causes reddish welts which itch. Though the bites are primarily annoying, the host's scratching may break the skin and permit infection. A large infestation on poultry may kill some of the birds. No diseases are transmitted by chiggers in the United States.

Life History -- Several species of chiggers (called redbugs) commonly attack man, causing intense itching and small, reddish welts on the skin. In North Carolina, these pests attack anyone who works or plays outdoors during summer. Chiggers pass through four developmental stages: egg, larva, nymph, and adult. Eggs hatch in about a week into larvae which are six-legged. Larvae are parasitic and attach to vertebrate hosts until they are fully engorged with tissue fluids. After feeding, larvae drop off their hosts and molt to nymphs which in turn molt to adults. Nymphs and adults are eight-legged and free-living. An entire life cycle requires about 50 days; there is usually only one generation per year in North Carolina. Little is known about the biology of nymphs and adults or the overwintering stage.


CONTROL

Before entering areas chiggers may inhabit, protect yourself by using a repellent. When applied to the skin and clothing, repellents are usually effective in repelling chiggers. Several pesticides are labeled to treat areas infested with chiggers.