Chiggers - How to Prevent & Treat Chigger Bites | Insect Shield


Technology - Insects We Repel - Chiggers

Chigger bites are caused by mite larvae. Usually red in color, the larvae are very tiny—only 1/120 to 1/150 of an inch in size. Most cannot be seen by the naked eye. Larger adult chigger mites measure 1/20 of an inch— which means they are visible, but they do not feed on people. Chigger mites belong to the genus eutrombicula and are arachnids, like spiders and ticks. (There are thousands of other species of mites, some of which feed only on vegetation.)

Beginning in spring, the chigger mite eggs hatch into six-legged, fast-moving larvae that climb onto vegetation where they seek prey. The mite larvae attach their claws tightly to their victims, piercing the host’s skin and injecting their saliva—which liquefies the skin cells of the host. After feeding on their host’s skin cells, the larvae drop off and develop into the eight-legged nymph-stage and, finally, into the adult-stage chigger mite, which is also eight-legged. Chigger larvae prey on many animals including cats, dogs, reptiles, birds and people. It takes about four days for a chigger to finish feeding on a human host.

A chigger bite causes a red welt with a white, hard center that itches intensely. The welt and itching, and sometimes swelling and accompanying fever, are a reaction to the mite’s saliva being injected into the skin. These symptoms usually appear 3 to 6 hours after attachment, and may last a week or more. Scratching can cause secondary infection, but chigger bites in the United States do not transmit infectious diseases to people.

Chigger bites are most likely to occur in late spring and summer. People tend to experience the most numerous bites when on or near grass or other vegetation, in a sunny location. Chiggers usually attach to people where clothing is tight over their skin, particularly around the waist, or where flesh is wrinkled or thin such as in the groin area, bend of elbows and behind knees, in armpits or on ankles.

The best way to remove chiggers involves lathering up with soap and rinsing with hot water, repeatedly. Quick removal can reduce itching; anti-itch medications provide some relief. Chiggers can remain in ordinary clothing, but will be eliminated after washing the garments in hot, soapy water. Bites itch for several days after the chiggers are gone.

By keeping your lawn mowed and trimming weeds or thick vegetation, you can make your yard less hospitable to chiggers—as they prefer to breed in damp, shady areas.

In eastern and southeastern Asia and India, northern Australia and some Pacific islands, chiggers can transmit scrub typhus, which is also known as tropical typhus or Tsutsugamushi disease. Scrub typhus occurs most frequently during rainy seasons in regions with scrubby vegetation and grass, but also shows up in desert, rain forest and sandy beach areas. No vaccine exists.