What Are Chiggers?

Usually called red bugs, berry bugs or harvest mites, chiggers are among the most common bugs. They can be found virtually anywhere, except deserts and places with exceptionally harsh and cold climate.

Chiggers like warm and moist places, as well as thick shade. They are mostly known for their intensely itchy bites. Unlike the majority of parasitic bugs, chiggers don’t feed on blood and don’t latch on to their hosts. Read on to find out what are chiggers, how they feed, and what to do if you get chigger bites.

Chiggers 101

Contrary to popular belief, and their insect-like appearance, chiggers are not insects. They belong to the Trombiculidae family, so they are arachnids, just like spiders and scorpions. Of all the Trombiculidae, only the ones that bite animals and humans in their larvae stage are called chiggers.

Chiggers tend to live in grass and forests. They prefer lower altitudes and moist climate. You can commonly find them in berry bushes, woodlands, orchards, and meadows. It is not uncommon for chiggers to inhabit drier places, such as parks, golf courses, and house lawns. In periods of high humidity, they frequent tall grass areas. On the flipside, in periods of low humidity, they prefer dark, shady places.

Chiggers mostly appear in spring and early summer, though, in warmer and more humid areas, they can be present all year long. They are very small, measuring around 0.4mm in length for the adults. The most common species in North America is Trombicula alfreddugesi, which is mostly found in the American Midwest and Southeast, as well as in Mexico.

Chigger Life Cycle

The life cycle of chiggers consists of four phases – egg, larva, nymph, and adult. Chiggers are only parasitic in their larval stage and that’s when they bite. In the nymph and adult phases, chiggers usually feed on plants. Here’s a quick overview of each of the life phases chiggers go through.

Egg Phase

Adult female chiggers usually lay their eggs in the spring, most commonly in grass. A female can lay up to 15 eggs a day. The eggs are round and dormant for about six days. Next, the chigger eggs evolve into a non-feeding pre-larva stage which lasts an additional six days. After that, chiggers turn into larvae.

Larva Phase

The larva phase is the only parasitic period in a chigger’s life. In this phase, they have three pairs of legs and are red in color. Chigger larvae are not all that picky, meaning they will indiscriminately use animals and humans to harvest the proteins needed to progress to the nymph phase.

They prefer warm and moist places and, in the case of humans, places covered tightly in clothes. Expect to find them around the waist, behind the knees, and around the ankles. Chiggers don’t actually bite; they pierce the skin with their mouths and inject enzymes that digest the tissue. Then, they suck up that stuff and eat it. In their larva stage, chiggers may remain attached to their host for up to five days.

Nymph Phase

After the feeding, chigger larvae leave the host and turn into nymphs. The nymphs are considerably bigger than the larvae and have four instead of three pairs of legs. They do, however, retain the red color. In the nymph phase, they are still sexually immature.

The first sub-phase is called protonymph, which combines the characteristics of a larva and nymph. Deutonymph, the next sub-phase, is the only period when the chigger nymph is active. During this period, it develops the fourth pair of legs. Finally, in the tritonymph sub-phase, it returns to inactive mode, awaiting the transition into adulthood.

Adult Phase

In the adult phase, chiggers achieve sexual maturity and full size (around 0.4mm). During this phase (as well as the deutonymph sub-phase) chiggers lead a predatory lifestyle, feeding on various arthropods. Also, adult chiggers feed on plants and are harmless to humans. They tend to live in the ground and are often encountered when digging in the garden.

Main Characteristics of Chigger Bites

A single chigger bite looks a lot like a mosquito bite. That being said, it is similar to bed bug and flea bites, too. It is an itchy red bump on your skin of several millimeters in diameter. A chigger bite may grow over a period of several days.

However, chigger bites can be distinguished from other similar-looking bites by the intensity of the itch. They tend to itch a lot more than mosquito and flea bites. Also, chiggers usually attack in groups. So, expect to see clusters of bites grouped in clusters. The rashes caused by chigger bites are called trombiculosis.

The places chiggers like the most are skin folds and those warm areas covered in tight clothing. That being said, the most common places to find chigger bites include the crotch area, ankles, behind knees, armpits, and waist.

It is important to note that most of the times humans don’t feel it when chiggers land on the skin or when they bite. The itch usually comes 24 to 48 hours after the bite.

How to Treat the Bites?

Unlike mosquito bites which disappear in a matter of days, chigger bites can take anywhere between one and three weeks to heal. But like mosquito and bed bug bites, chigger bites tend to go away on their own.

If you think you’ve been bitten by chiggers, wash the affected area with warm water and soap immediately. Try to avoid hot water. After washing the bites, apply some antiseptic to the area. Don’t think that you have to remove the chiggers from the bites, as they don’t burrow under the skin.

Also, keep in mind that chiggers feed on skin cells, not blood. Chiggers don’t transmit any disease, either.

Avoid scratching the bites, as bleeding chigger bites can become infected. If you start to feel sick, nauseous, or any other symptoms of an infection, call your doctor.

How to Prevent Chigger Bites?

You can lower the chances of getting bitten by chigger larvae by staying away from tall grass and thick underbrush during the spring, summer, and autumn months. Also, keep your front lawn neatly mowed.

If you decide to go on a camping or fishing trip, make sure to wear long-sleeve shirts and long pants. Tuck the pants into your socks. Avoid open-toed footwear, as well as walking barefoot in tall grass. Additionally, you can apply bug repellents.

Conclusion

Chiggers are tiny arachnids that feed on skin cells. Their bites look very similar to mosquito bites except a lot itchier. Chiggers don’t carry or transmit infectious diseases and their bites don’t have any side effects besides the itch.

Chigger bites go away on their own, unless they become infected. That being said, they can take up to three weeks to fully heal. Warm water and soap are the best way to treat the bites.

 

References:

https://nfs.unl.edu/chiggers-and-trombiculosis

http://www.aavp.org/wiki/arthropods/arachnids/prostigmata/chiggers-trombiculid-mites/