These mites are of the Arachnid group that includes ticks, scorpions and spiders. They can inhabit almost any habitat and, like ticks, are predators. Some of the names these mites go under include, red bug, furniture mite, flour mite and harvest mite. Like their cousin the tick, chiggers are the source of much folklore and myth.
Although the numbers of varieties exceed 3o,ooo species there are primarily 2 species that cause problems in the United States. Persons risking chigger contact should consider use of repellents containing permethrin. These clothing treatment repellents protect against chiggers, ticks, and mosquitoes by actually kills these predators prior to attack. By the time you are experiencing severe itch and discomfort of a chigger attack the chigger has long since gone.
Like ticks the chigger adults lay their eggs on the soil or vegetation. When the eggs hatch the new young crawl onto low vegetation and set their ambush of some passing host. As with young ticks, the chigger mites are tightly grouped since hatching and are slow to expand from their birthplace site. This is why people and animals attacked by young chiggers or ticks will can find numerous bites versus single bites. Unlike ticks that may need to feed for several days, the chiggers feed briefly then drop off. Feeding areas are commonly found where tight fitting clothing makes contact with the skin.
The chigger does not burrow under the skin but instead injects anticoagulants and other compounds that partially dissolve the skin, it’s this dissolved skin that the chigger prefers. After several hours or sometimes a few days the chiggers are fully fed. The dermatitis and intense itching is caused by the fluids forced under the skin during the feeding and does not begin until after the chigger has dropped off. Some pharmacists recommend Tincture of benzyl benzoate as a good chigger itch reliever.
Larval mites (trombiculidae) commonly called chiggers and red bugs are mostly lymph-feeding (1) parasites of vertebrates’ (2). Many of the various species cause either a scrub itch as an allergic reaction to the chiggers’ saliva, or transmit human disease organisms. Among the important chigger-borne diseases are scrub typhus or tsutsugamushi disease, which occurs in many east and southeastern Asian counties. The most common issue of chiggers infesting humans is the scabies or itch mite. Most common areas affected are the hands and wrists. Many species of food mites can cause dermatitis (3) in people handling infested food.
Credits:
Animal Odyssey’s I, by Dr. Robert Breene III
The Encyclopedia of Insects, edited by Christopher O’Toole
A manual of Acarology, by G.W. Krantz