What Are Midges?
Despite the cute sounding name, midges can be a real nuisance. Midges are actually many different species of tiny flies. Not all species bite, but, like mosquitoes, the females of some species need blood in order to reproduce. Their mouthparts include cutting teeth that break the skin to extract blood. These bites can be quite painful.
Although biting midges may be a nuisance to us, many midge species are important food sources for insectivores like fish, frogs, swallows, and spiders. There are over 47 species of biting midge in Florida alone!
Some adult midges look similar to mosquitoes, with the same dark brown coloring on their bodies and wings, and bodies that extend beyond their wings. Most biting midges look like stocky flies, with wings that are only as long as their body. The female's body expands and takes on a reddish brown color as it draws in blood while feeding.
In the United States, midges are often called "no-see-ums" because they are so small and hard to see. At 1 to 3 mm in length, the body of a small midge is about the size of a pencil point! Large midges are less than 1/8 inch long.
Male midge flies are most easily seen when they circle in the air together as a swarm. You have probably seen these midge swarms yourself! Females may be present, but males do not bite. Swarms are annoying, but you are unlikely to be bitten by a swarm of males.
Fun fact: Some fishing enthusiasts like to use lures that look like midge larvae!
Are Midge Bites Dangerous?
Some biting midges can spread diseases like bluetongue virus to livestock and African horsesickness virus to horses, deer and other animals, but they are not known to transmit diseases to humans in North America.
There are species of no-see-ums in Central and South America, Africa, and some Caribbean islands, whose bites cause infections in humans that lead to dermatitis and skin lesions. Fortunately, these midges have not spread to North America.
The itching and swelling produced by midge bites in humans are an allergic reaction, not a disease. See How to Treat Midge Bites below.
Where Do Midges Live?
There are over 4,000 species of biting midge, and they are found all over the world.
Midges live in coastal areas, swamps, riverbanks, ponds and marshy regions. The lifecycle of biting midges is similar to that of a mosquito. They lay their eggs in standing water or, in some cases, wet soil.
Larvae grow in debris at the bottom of the standing water, followed by a pupa stage when they begin to form wings and legs, moving toward the surface. The larval stage can last up to a year, often through the winter, depending on the climate. Midge larvae play an important role in the ecosystem by helping to break down leaves and other organic material on the bottom of these watery areas. The rest of the life cycle usually lasts two to three weeks - plenty of time for adults to mate and females to bite you, and then lay more eggs!
Most midge species do not stray very far from their breeding sites. Females may travel up to a mile to look for a tasty meal. Adult male midges come out to gather in swarms at dawn or dusk.
People living in midge-infested regions can apparently build up immunity to the irritation caused by midge bites. So, generally, midges create the most nuisance for people who travel to an area where midges are present. For example, hunters, fishermen and golfers who travel to places in the United States where midges are common often report being under attack by large numbers of no-see-ums.
Like mosquito bites, midge bites often cause irritation and leave tell-tale signs:
1. Clusters of red dots
2. A small hole in the middle of the bite where skin was punctured
3. Some reactions to midge bites can be severe: People who are sensitive to insect bites may feel a burning sensation followed by red welts on their skin.
4. People who are extremely sensitive to bites may develop painful, itchy blisters filled with fluid.
How to Repel Midges and Prevent Bites
It’s not always easy to prevent midge bites, but there are precautions you can take. If you have to be outside when midges might be present, follow these tips:
1. Know when midges are active in your area, usually at dawn and dusk.
2. Avoid midge breeding areas like marshes and ponds.
3. Wear Insect Shield repellent clothing. Insect Shield clothing provides excellent protection from midge bites by covering arms, legs, neck and head without the toxicity and mess of DEET or other topical repellents.
4. Apply permethrin spray to your clothing and gear.
5. You can also send your clothes to Insect Shield and we will treat them with our repellent for you. This treatment lasts up to five times longer than permethrin spray you apply yourself!
6. On exposed skin, you can use topical insect repellent with DEET or Picaridin.
Midge bites can be uncomfortable, but, in North America, they are not known to spread disease to humans. You can take some simple steps to ease the discomfort of bites:
1. Wash the affected skin with mild soap and water and pat dry with a clean towel.
2. To relieve the itch, apply a clean washcloth soaked in cold water several times for 5-10 minutes.
3. To reduce swelling and the itch, ice the area with a cold pack or ice cubes wrapped in a clean cloth.
4. Consider taking an over-the-counter antihistamine.
5. Use antiseptic creams if you have scratched bites and made them bleed.
6. Be sure to see a doctor if you are having an allergic reaction to the bites, or the pain and swelling has not gone away after a few days.