Gnats swarm South Carolina each spring. Here’s how to keep the pest away

• Gnats emerge in South Carolina during the spring as temperatures rise, becoming a nuisance for outdoor activities.
• South Carolina has two common types: biting gnats that feed on blood and non-biting eye gnats attracted to bodily fluids.
• Gnats are most active at dawn and dusk when temperatures are above 70°F, with their peak season from late spring to early summer.

In South Carolina, spring officially begins on March 20 and lasts through May. As temperatures rise during this period, it’s common to see gnats and other insects emerge, signaling the arrival of warmer weather.

Gnats can have a big impact on the enjoyment of springtime in the Palmetto State. These flying insects can disrupt outdoor activities by biting people, making them a nuisance for those who enjoy spending time outside.

A study by Skitopel found that gnats are most active during dawn and dusk, with large mating swarms often appearing around sunset. Their peak season typically occurs from late spring through early summer.

During the spring season, here is what you need to know about gnats.

Are there different types of gnats?

South Carolina residents may encounter biting gnats and eye gnats.

Palmetto Exterminators states biting gnats are around 1/16 inches in diameter, also known as no-see-ums, and cut through the skin to feed on blood, leaving behind itchy, red welts that can cause discomfort.

These tiny pests are often found near water bodies, making lakes and rivers hotspots for encounters. The mud around these moist areas is where females lay eggs and larvae develop.

On the other hand, eye gnats are around 1/8 inches in diameter and do not bite, but swarm faces looking for bodily fluids like mucus, sweat, and even tiny wounds, and they prefer sandy soil environments.

Eye gnat females lay their eggs and larvae in the soil in these areas, while animal manure can increase breeding activity.

They can lay up to 500 eggs in their short 7-10 day lifespan, and gnats only live 28 days to complete their life cycle.

At least one species of these insects can be found on every continent.

When do gnats usually come out?

Gnat activity generally increases as temperatures exceed 70°F and remains high throughout the summer months, making them a persistent presence during outdoor gatherings.

How to keep gnat populations low?

According to a study performed by Clemson University’s Home and Garden Information Center, due to the abundance of biting midges and eye gnats in certain areas, it’s challenging to control them area-wide.

A variety of broad-spectrum insecticides have been tested, but populations are rapidly replenished from breeding sites. To keep gnat populations under control, it is recommended to apply insecticide every day.

How to keep gnats away?

Clemson University’s home and garden information center found that screening porches or other outdoor areas with screening (20×20 mesh or smaller) can exclude biting midges. While in most cases, an 18×16 mesh screen is enough to keep eye gnats away.

Additionally, a ceiling fan installed under a covered porch or a box fan can help keep gnats away, as they are small enough to be blown off course by air movement.

Insect repellents containing DEET may be used to repel gnats temporarily, providing relief during outdoor activities.

Palmetto Exterminators recommends that if you want to keep gants away the DIY way, you can put out a bowl of apple cider vinegar mixed with water and a splash of dish soap.

The vinegar draws them in, and the dish soap cuts the surface tension so they sink when they land on the surface. 

These strategies, combined with regular maintenance and cleaning of outdoor spaces, can significantly reduce gnat presence in environments.

Disease dangers from gnats

In some cases, infectious diseases can be transmitted by biting and eye gnats, according to a study performed by Clemson University’s Home and Garden Information Center.

Biting gnats have been linked to parasite infections and bluetongue, a significant disease affecting sheep and cattle, transmitted by various species of Culicoides midges.

Eye gnats can transfer disease-causing organisms such as bacteria, potentially causing pink eye, sepsis, mastitis in cattle, and vesicular stomatitis in horses, sheep, goats, and pigs.

Travis Jacque Rose is the trending news reporter for the Greenville News, part of the USA TODAY Network. Reach him at trose@gannett.com