(4/30/18) BATON ROUGE, La. — They have many different common names and cover several different species, but one thing they all have in common is they are a nuisance to people and livestock.
These pests are called turkey gnats, buffalo gnats and no-see-ums, just to name a few. They are members of the black fly family and are a problem mostly during the late winter to early spring, according to Sebe Brown, an LSU AgCenter entomologist at the Tom H. Scott Research, Extension and Education Center in Winnsboro.
Like mosquitoes, adult gnats feed on blood. Some gnat species will swarm around livestock and people, cutting the skin of their host and feed on the blood, Brown said.
“Black flies will secrete an anticoagulant that can cause an allergic reaction and prolonged itching in sensitive individuals,” Brown said. “In livestock, they can cause toxemia, anaphylactic shock, and in extreme cases, have caused suffocation.”
A female gnat has the capability to lay between 100 and 600 eggs. Immature gnats, like most aquatic flies, spend their time in water as filter feeders. Adult populations exist for about one month in the spring, and the eggs laid by the females will develop the following spring, he said.
Unlike mosquitoes, there are few effective options for controlling gnats around people.
“Some products containing DEET or Picaridin have had some limited success against gnats,” Brown said. “Some use unconventional products such as Avon Skin-So-Soft or Victoria’s Secret Amber Romance.”
Some of these unconventional products have naturally-derived ingredients such as citrus or vanilla, which may contain some repellent properties. Brown said no scientific research supports unconventional products controlling these insects around people or homes.
For livestock, repellant products containing permethrin or ivermectin ear tags, smoldering fires that produce dense smoke and providing shelters may offer relief from these pests.
“Black flies generally will not enter into enclosures or barns and are only active during the day,” Brown said. “Livestock can get some relief by housing animals in dark areas of enclosures and turning animals out at night.”
Brown said that permethrin or any pyrethroids-class products should not be used on cats.
A silver lining with these gnats is once temperatures consistently stay about 80 degrees, their occurrences go down. With this year’s cooler weather, the gnats may have an extended season.
But just as the gnats begin to dwindle, mosquito numbers are expected to increase, and there will be another pest to bother people and livestock.
The LSU AgCenter and the LSU College of Agriculture