What You Should Know About Chiggers

By William McCaleb. Program Assistant, ANR I just read a great article put out from Ohio State Extension, authored by Ashley Kulhanek about chiggers and just had to share with you all since many of you have been itching and scratching after being outdoors. The culprit might be the mighty small chigger. Ashley started her article out by saying “Summertime was made for chiggers”. She is right on the money on that statement. Laying in the grass, playing outdoors, and gardening puts us right in the path of chigger bites. But what ARE chiggers anyway? And are you correct in calling that itchy leg their fault?
The larva of the chigger can cause serious itching because of their salvia. (courtesy of Clemson Cooperative Extension Chiggers are mites (Eutrombicula spp.) whose saliva causes intense, irritating itching in humans and animals. It is the mite's LARVAL life stage that is parasitic and feeds on humans. During the rest of its life, it is a beneficial predator of insect eggs and small arthropods like springtails. Chigger mites tend to be yellow-to-red in color though are usually too small to see. Chiggers are often mistaken as the red velvet mites, concrete mites, and clover mites that frequent our patios and lawn furniture. These are large mites, easily visible and thus quickly targeted as the source of our woes. Unfortunately, it's never that easy! Those larger red mites are NOT responsible for bites or itching in humans though they can stain clothing if sat on, and some may even be accidental invaders into homes. Just a few quick tips on chiggers. Chiggers do NOT burrow into skin. This is a myth! Chiggers do not suck blood, instead they actually feed on dissolved skin cells. Also, you should know that only the larval stage affects humans, not the adult. Chiggers are very small (0.6 - 0.25mm) and are often unseen by the casual viewer. A good shower using soap and water will remove the mite. Once this mite has done its ‘thing’, itching can still last up to two weeks. That itchy feeling is the result of your skin's reaction to the mite saliva and can vary person to person; small red welts are common. You should always contact your physician to discuss symptoms, reactions, and treatment options. For those of us who enjoy learning about the biology of insects, this little critter has a unique lifecycle: Egg, Larva, Nymph, and Adult. This mite larva has only 6 legs. Only after this mite molts into its nymph stage does it possess all 8 legs characteristic of mites and the other arachnids. Mites can molt through several nymphal stages before reaching adulthood and sexual maturity. It can take weeks to months for the cycle to complete, depending on weather, temperature, and conditions. Females can produce several generations a year resulting in high numbers of mites in a given area and repeated trouble with chiggers throughout the season. Chigger mites overwinter in the adult stage in the soil. When temperatures increase, they emerge, mate and lay eggs in the soil in overgrown areas including uncut grass, fields, scrubby or weedy areas. Larval mites will climb to the end of grass blades or plants and wait to be picked up by the legs of animals and humans. When we walk by or play in the grass, the mites hitch a ride. They prefer to snuggle into spaces where tight clothing or elastic gives them shelter; therefore, the resulting itch may be focused around elastic on socks, ankles, waists, bra straps and armpits. Chiggers will also feed on birds, mice and other rodents, cats and dogs, even reptiles, in addition to humans. The larval stage is like any teenager; always hungry and looking for their next meal. The baby mites excrete salivary enzymes into skin, often at the base of a hair follicle, in order to digest skin cells into a slurp-able shake. The dying skin cells form a stylostome, a tube-like channel from which the larva sucks the digested skin slurry. AKA your own skin forms a little straw that the mite uses to drink up. Chiggers can feed for 2-4 days on their host, but on humans we usually knock them off long before they can complete a meal through movement and scratching. After feeding, larval mites drop off and molt into nymphs, moving onto different food items. The itching reaction and welts can take several hours to develop and will last well beyond the mite's presence. You can shorten feeding time by quickly washing up after being in chigger territory. Because they have not burrowed in, thoroughly wiping down exposed skin with a wash cloth or taking a good shower or bath will easily dislodge and remove the mites. Bathing also kills the chiggers. Make sure to wash clothing soon after as well to kill any remaining mites left on exposed clothing. The And lastly, stay away from folk remedies you may have heard. There is no need to apply anything other than soap and water to remove the mite. Then you only need to deal with the aftermath by addressing itch. Speak with your medical provider or a pharmacist for recommendations on dealing with the itch. PREVENTION They do not feed long and the itching is just the prolonged reaction to their spit... so PREVENTION is the best solution. Using insect repellents and wearing protective clothing can reduce incidents of all manner of bug bites, including chiggers. For those of you who have served in the military you probably learned all about prevention and treatment through a guide that was put out by service you were in. This researched information is supplied to recruits and Inservice personnel from the Armed Forces Pest Management Board. Chiggers prefer overgrown, grassy habitats. These transition zones along paths, fields, thickets and scrub could harbor chigger mites, in addition to our own yards. Long-term solutions could include brush control, frequent mowing, and landscape changes that increase light exposure and air flow (less humidity). These changes can make your yard less appealing to mites and ticks. You can survey your yard for chiggers as well by placing a black square of cardboard down in the lawn. After about 10 minutes, mites will start to crawl up onto the black surface and there you have a better chance of seeing those tiny specks. A magnifying lens will help you check for their presence. Look for yellowish-red dots darting about. Insecticides are not generally recommended as rebound populations may occur and only the larval stage is a problem. However, hot-spot treatments are an option for quick knock-down in the short-term. There are several products on the market for use in Virginia. Please contact your local Virginia Cooperative Extension office for recommendations, if you need help determining the right product. Remember, the label is the law, so you do not want to use the wrong product or use a product at the wrong time. Remember there are OTHER things in the wild that can make you itch, including poison ivy, mosquitos, and other skin allergies. Extension Staff are NOT MEDICAL PROFESSIONALS and cannot identify bites or diagnose clients with chiggers or other skin ailments. We cannot recommend treatments for skin conditions. Speak with your medical provider if you are having problems with itching or severe reaction to chigger saliva or other irritations.