This is a magnified view of a chigger.  It’s almost impossible to see chiggers crawling on the skin as they prepare to bite, and they deliver a vicious bite.  Beware of the chigger!  (Photo courtesy Hansell F. Cross, Georgia State University, Bugwood.org)

One of the most feared, parasitic bugs in the United States is too small to see as they crawl across the skin in an effort to feed.  It’s the tiny, red chigger and it’s best viewed under a magnifying glass.

Chiggers don’t feed on blood, they feed on skin.  Despite their small size, the chigger can deliver a bite that will itch and burn many times worse than a mosquito bite.  And the welt that forms on the skin after a chigger bite may last for weeks.

September is the month that the chigger is most active in our area.  They prefer a temperature in the 70s and lower 80s and become less active when the temperature soars over 90 degrees or falls under 60 degrees. It’s currently chigger season in the Middle Atlantic region.

The good news is the chigger is not as common in the Washington, D.C. area as places to our south, even as close by as Richmond, Virginia.  The bad news is the chigger can still be found in the D.C. area in isolated pockets, and an encounter with these little buggers can make your life absolutely miserable for about two weeks or more if you have the misfortune to step where they reside.


Itchy welts are produced from chigger bites. (Wikipedia)

Chiggers are the larvae stage of the harvest mite.  Like ticks and spiders, they belong to the class Arachnida.  At 1/50th of an inch or less in diameter, they are almost impossible to see on skin and clothing.  Most people never feel them deliver the bite.

Much like a tick, when the chigger bites, it’s painless and initially itch-free.  The insanely itchy welt appears about 12 to 24 hours after the bite.  Unlike a tick, chiggers in the United States do not carry disease.

The digestive chigger bite

During a chigger bite, the chigger’s mouth parts inject saliva into the skin that contains a digestive enzyme which causes skin cells to rupture and turn to liquid.  The skin is partially digested even before it enters the chigger’s body.  The chigger then drinks the dissolved, digested skin tissue.  While a chigger is attached to the skin, it will continue to inject saliva under the skin.

A hard tube or stylostome forms in the skin as the victim’s body reacts to the chigger’s saliva.  The stylostome acts as a straw that allows the chigger to drink the liquified skin.

If the chigger’s saliva and associated stylostome penetrates the lower levels of the skin, the resulting welt can be particularly large and itchy.  This is one reason why a chigger welt can last for several weeks.  It takes time for the body to heal a hardened tube in the skin that is filled with chigger saliva and liquified skin.

Scratching helps dislodge the chigger and stops the injection of more saliva into the skin.  If a chigger victim has only a few bites, it’s easy to scratch away the chiggers.  If a victim has several hundred chigger bites, however, it’s more difficult to scratch away all of the chiggers.  It’s not uncommon for an unfortunate victim to be covered by hundreds of chiggers.

The chigger bite (Wikipedia)
The chigger bite: The chigger’s mouth parts inject saliva into the skin that contains a digestive enzyme which causes skin cells to rupture and turn to liquid.  The saliva slowly dissolves a hole in the skin which forms a hardened tube called a stylostome.  The chigger then drinks the dissolved, liquified skin tissue from the tube.  The longer a chigger is attached to the skin, the deeper its saliva will penetrate below the surface of the skin.  (Wikipedia)

Chigger habitat

Chiggers reside in low, damp vegetation with partial sunlight.  This habitat includes many creek beds in our area.  They also can be found in tall grass along wood lines and in English ivy that is partially shaded.  Chiggers are NOT found in mowed grass or on dry ground.

Ticks are more robust than chiggers and can be found in many more types of vegetation and terrain.  Chiggers prefer moist vegetation close to the ground.

When you walk along a trail in late summer or early fall, stay in the center of the trail and try not to let your legs rub against vegetation.  Most vegetation is free from chiggers but it only takes one ill-fated step to pick up dozens of hitch-hiking chiggers.

Golfers are at risk this time of year.  If you are golfing and the ball is sliced into the woods, do not walk into thick vegetation looking for the ball.  One golf ball is not worth the potential of dozens of chigger bites, not to mention picking up ticks.  Open woods with dead, brown leaf cover are usually free from chiggers, however.

Fishermen are also at risk.  If you walk the shoreline looking to cast your bait, don’t stand in thick vegetation.  Stand on ground where vegetation does not contact your legs or feet.


Damp vegetation in partial sunlight are where chiggers often reside.  Avoid walking through this type of vegetation in the late summer or early fall.  (Kevin Ambrose)

The chigger patch

Chiggers are found in clusters or patches.  It’s common for one person in a group to get covered by chiggers while everyone else does not get a single bite.

For example, a group of people can walk the same trail, fish the same stream, or search for golf balls in the same woods, but only one unlucky individual gets all of the chigger bites.  The person who stepped into a chigger patch can get 100+ bites while everyone else is bite-free.

If you talk to enough of your friends, you’ll probably find someone you know who has stepped into a chigger patch and encountered many chiggers.  It’s an event that they will never forget.

To avoid chigger patches, the simple rule is to not step into vegetation this time of year.  Stay on dry ground or pavement.  It’s that easy.


Chigger bites after 10 days are still inflamed and itchy.  (Wikipedia)

The chigger myth

Chiggers do not bury themselves in the skin or lay eggs under the skin.  The fact that nail polish should be used on chigger bites to suffocate the bugs is false.  Once the chigger bite is visible, the damage has been done.  The chigger has probably been scratched off or has fallen off.  Nail polish is useless for chigger bites.

Calamine lotion can be used on the bites and Benadryl can be taken to help relieve the itching.  There is no simple cure, however.  The bites will itch regardless.

Prevention

If you have to venture into thick vegetation during the late summer or fall, here’s one way to prevent or minimize chigger bites:

Wear tall boots, three pairs of socks, and long pants.  Tuck the bottom of the pants under the top layer of socks and spray the pants, socks, and boots with Deet.  Try to minimize the time in vegetation.

Once out of the woods or field, immediately remove the clothing and place it in the wash.  Quickly take a hot shower and scrub well with a wash cloth.

Frost to the rescue

The good news is that after a frost or freeze, chigger season is over.  During late fall and winter, our region is chigger-free.  Roam the woods and fields and enjoy the crisp air without the worry of chigger bites.

After the first snow, you can definitely forget about chiggers for at least another six to eight months, before the terrible chigger cycle repeats.

Let us know if you have any chigger experiences or tips for prevention.