COLUMBIA–Summer is in full swing and people are gardening, picnicking, hiking, fishing and, unfortunately, dealing with biting pests.
“One of the most notorious biting pests is the chigger,” said Richard Houseman, University of Missouri Extension entomologist.
A chigger is the parasitic immature stage of a mite. The adult mites are harmless. Chiggers normally live on rodents or birds. Humans are only accidental hosts and usually encounter chiggers in moist areas with low-growing shrubs, tall grasses or weeds.
Chiggers have a clumped distribution, so a person sitting in one spot may endure many bites while a person a few yards away may not be bitten at all.
When a chigger attaches to you, it settles to feed in an area where clothing fits tightly against the skin. Chiggers don’t suck blood. They form a tube within the skin that they use to inject digestive enzymes and suck up dissolved skin tissues.
Scratching dislodges the chigger and kills it, but the feeding tube remains and will continue to cause discomfort until the body has had time to neutralize the enzymes and repair damaged tissue.
Dissolved tissue will ooze out of the bite each time you scratch, forming a hardened cap that is a distinct feature of chigger bites. Scratching also increases the risk of secondary infection. You can treat itching with medicated creams, but only time will heal the tissues, Houseman said.
Your best defense against chiggers is avoiding chigger-infested areas. Keep weeds and grass trimmed around the home and garden. Wear appropriate clothing if you must go into chigger habitats. Avoid wearing sandals, shorts or sleeveless shirts. Button collars and cuffs to keep the pest outside of your clothing. Tuck pant legs inside your socks. Use mosquito-type repellents on the outside of your clothing.
For more information, see the MU Extension guide “Chiggers” (G7398), available for purchase or free download at http://extension. missouri.edu/publications/DisplayPub.aspx?P=g7398.
