Where they breed, why they bite, what to do about them
This April and May, people were gleeful that spring was in the air, but spring was not the only thing sharing the airspace, unfortunately.
There were also gnats.
So many, at some places, that a Herald reader wondered what she could do about them, among other questions. She said there were times when gnats were swarming all over her door on the beachfront in North Wildwood.
She was concerned that there were more gnats in 2024 than in previous years, and asked whether something was responsible, and how the gnats could be controlled.
The first question, then: Are they seasonal?
This reporter has had some experience with biting gnats, on the Washington Street Mall in Cape May. I used to work for a retailer who participated in the twice-a-year sidewalk sales sponsored by the Mall Merchants Association. The spring sidewalk sale was normally held around the third Thursday in May. Along with the crowds of bargain hunters came the biting gnats. Or at least we called them gnats.
“Gnats encompasses a whole group of flying non-mosquito insects that we call midges,” said Peter Bosak, who earned his Ph.D. in entomology, meaning he is a “bug doctor.”
Bosak said a lot of people call gnats, which have the Latin name ceratopognidae, “No See ‘Ums,” and they are commonly called “biting midges.” The gnats we encountered in the spring in Cape May did bite. So did the ones mentioned by the reader, as do the black flies that appear in the spring in certain areas in the Northeast and Midwest.
As a boy I remember hearing about the black flies that plagued the Lake Michigan shoreline of Wisconsin. I was in the Adirondacks for about a year, and people there battle black flies each spring, although I didn’t encounter them during the time I was there. Many stores sold black fly repellent, which often contained peppermint.
It seems that the gnats are seasonal, as in mid- to late spring, and then they are gone. I believe there are flies that are larger and come later in the summer, particularly when the wind is coming from the west, meaning off land.
That was the second question: Are they worse with the west wind?
Gnats, black flies and sand flies are lightweight and can be moved about by the breeze.
“They are at the mercy of the wind,” Bosak, who is retired, said.
That might explain why gnats were on the reader’s screens on the ocean side of the house and not the bay side: If the wind was coming from the west, they might be able to congregate on the side that is not getting the wind.
Bosak said the gnats that generally bother people on the beaches breed in the marshes west of the barrier islands, specifically along the rack line, or the water’s edge. Other biting flies, such as greenheads, breed in the peat areas of the marsh.
The gnats’ larvae like the flotsam and jetsam that accumulates along the water’s edge. Not having dunes is not a factor in the number of gnats along the beach.
Is there a time of day when they swarm?
Generally, gnats are active during the day, and the night shift belongs to mosquitoes. It’s hard to say gnats swarm, because different types of gnats or midges seem to swarm, and others do not. One type tends to fly around the eyes, making them particularly annoying, Bosak said.
Whether a gnat bites depends upon the type of gnat and whether it is male or female. Female gnats, like female mosquitoes, take a blood meal from the host for protein for the development of eggs. Otherwise gnats and mosquitos feed on nectar. Gnats have a life cycle that can range from two weeks to six weeks.
Are they worse than in the past five years? Bosak said that, although it might seem like it, there is really no way of knowing.
Worldwide there are around 1,700 species of gnats that have been identified, and scientists believe there are another 20,000 that haven’t been discovered yet.
Probably the most important question: How can we control them?
If the “we” means the county government, it is unlikely the county’s Department of Mosquito Control will be spraying for gnats, which in the United States have not been found to carry disease. Mosquitoes, of course, have long been known to carry harmful diseases.
It is important to note that all insects are part of a natural food chain, and just because there is an abundance of them, that alone is not a reason to eradicate them.
According to Bosak, one man contacted him when he was with the Mosquito Commission and complained that there were too many dragonflies around his house. He wanted the county to spray for them.
“I told him, ‘You realize that they eat thousands of mosquitoes,’” Bosak said.
The man was not convinced.
While the county might not spray for gnats, there are easily found gnat repellents that can be used on your body and face. Among them are a vanilla repellent, peppermint oil, eucalyptus oil and rosemary oil.
Visit 15 Simple Gnat Repellents that Really Work (tipsbulletin.com) for more information.
Contact the reporter, Christopher South, at csouth@cmcherald.com or 609-886-8600, ext. 128.
