A chigger or red bug is an immature stage (larvae) of the harvest mite.  These microscopic mites are close relatives of ticks, measuring 1/100 of an inch and have a red-orange hue. Unseen to most, chiggers may not be noticed aside from the itchy, festering red welts left on lower legs and ankles. Chiggers that attach to humans usually die within 24 to 72 hours.

Biology

The harvest mite goes through four stages of development:  egg, larva, nymph and adult. The development from egg to adults takes about eight weeks.  Once the egg hatches, the parasitic larvae finds a good position on tall grass or other vegetation so it can spring onto a passing human or animal.  After feeding for two to four days, the larvae drop from the host, undergo a molting process, and become nymphs. Nymph and adult harvest mites feed mostly on plant life and don't bother humans or other mammals. The life cycle is about 50 to 70 days, with adult females living up to one year and producing offspring during this time. Multiple generations occur in warmer climates, especially in the Tennessee.

Chigger Facts:

• Chiggers do not burrow into the skin or suck blood. It attaches to its host, injects digestive enzymes into the bite wound, and then sucks up the digested tissue
• Warm, rainy days make these parasitic and predatory mites reproduce into large populations.
• Once the ground temperature is regularly above 60°F, the harvest mite lays eggs, and “chigger season” is underway.  This season typically begins in April and ends in the early autumn/first “frost.”
• Chiggers do not like sunlight or humidity. During the wet season, chiggers are usually found in tall grass and other vegetation.

 Chigger Myths

• Applying finger nail polish to red bumps/bites on our skin does not help.  By the time the severe itching occurs, the chigger is nowhere found. 
• Chiggers do not drink blood.  Chiggers drink liquefied skin cells. 
• These pests are mites, not insects.
• The red welt/bump on skin is not where a chigger laid eggs.

Prevention

• Keep grass short.
• Remove brush and wood debris where potential mite hosts may live.
• Keep major host away from the area, such as - rodents and other small mammals.  Secure trash cans to discourage wildlife from coming near your home.
• Sunlight that penetrates the grass will make the lawn drier and make it less favorable for chigger survival.

Medical Treatment

To reduce discomfort, apply an anti-itch cream that contains hydrocortisone, benzyl benzoate, or calamine. Some people may be sensitive to these medications, so if you have questions, be sure to ask your health-care professional or pharmacist.