Yes, chiggers are present in Illinois. These tiny mites are common in the state, particularly during warmer months, and can cause intensely itchy bites.
Understanding Chiggers
Chiggers are not insects but rather the larval stage of mites belonging to the Trombiculidae family, relatives of spiders and ticks. These arachnids are microscopic and often yellowish to light red. Only the six-legged larval stage of the chigger is parasitic and feeds on humans and animals. Adult chiggers, which have eight legs, are not parasitic and instead prey on small insects and their eggs in the soil.
Habitats and Biting Behavior
Chiggers are found outdoors in Illinois, particularly in tall grasses, weeds, and brushy or wooded areas. They thrive in damp, shaded spots and are most active when ground temperatures range between 77 to 86 degrees Fahrenheit. When a host passes by, chigger larvae climb onto them from vegetation.
Contrary to a common misconception, chiggers do not burrow into the skin or feed on blood. Instead, they attach to the skin, often in areas where clothing fits tightly or where the skin is thin or wrinkled, like ankles, waistlines, armpits, and behind the knees. Once attached, the chigger injects digestive enzymes that break down skin cells, forming a feeding tube called a stylostome. The chigger then consumes these liquefied skin cells. The intense itching is a reaction to these enzymes, not the chigger itself. Chiggers typically feed for a few days before detaching, but they can be dislodged sooner by scratching or washing.
Identifying and Treating Bites
Chigger bites typically manifest as intensely itchy, red welts that can resemble pimples, blisters, or small hives. The itching often begins several hours after exposure and can be severe, sometimes lasting for several days or even up to two weeks. Bites frequently appear in clusters, especially where clothing is tight, such as around sock lines, waistbands, or in skin folds. A tiny red dot, which is the remains of the stylostome, may sometimes be visible at the center of the welt.
Treatment focuses on alleviating intense itching and preventing secondary infections. After potential exposure, wash the affected skin thoroughly with soap and water, scrubbing vigorously to dislodge any remaining mites. Washing clothes worn during exposure in hot water can also help eliminate chiggers. Over-the-counter anti-itch creams containing ingredients like calamine lotion, hydrocortisone, or menthol can provide relief. Oral antihistamines can also help reduce itching. Avoiding scratching is important to prevent skin breaks that could lead to bacterial infections. If symptoms worsen, show signs of infection, or do not improve within two weeks, consulting a healthcare provider is recommended.
Preventing Chigger Exposure
Preventing chigger bites involves personal protection and habitat management. When in chigger-prone areas, wear protective clothing. This includes long-sleeved shirts and long pants tucked into socks or boots to create a barrier against the mites. Light-colored clothing may also make chiggers easier to spot.
Applying insect repellents is an effective preventive measure. Products containing DEET can be applied to exposed skin and around clothing openings, such as cuffs and waistbands. Permethrin-treated clothing offers long-lasting protection, killing chiggers on contact; however, permethrin should be applied to clothing and allowed to dry, not directly to skin.
After outdoor activities, showering with soap and water as soon as possible can help remove any chiggers that may have attached. Keeping grass mowed short, trimming brush, removing weeds, and clearing debris like leaf litter can reduce chigger habitats around homes. Improving air circulation and sunlight exposure in your yard can make it less hospitable for chiggers.