Numerous calls coming into the Extension office this week were inquiries about the pesky gnats swarming the area. In fact, just about everywhere I visited last week there was someone more than willing to fuss about how they have been pestered by the menacing bugs. We have even received reports from individuals with backyard poultry flocks losing chickens to suspected problems associated with the gnats. 

Most commonly the callers wanted to know what these pests are and how to avoid them. These pests are known by several names — black flies, buffalo gnats, turkey gnats and a few other less-friendly names I dare not send to print.

Black flies are tiny blood-sucking flies in the insect family Simuliidae. Contrary to their name, black flies may be gray, tan, or even greenish. They usually breed in fast moving water of streams and rivers and are tremendous pests of humans, domestic animals and wildlife every spring in northern areas of the United States and Canada. In Mississippi, buffalo gnats are usually not a problem, but every so many years outbreaks are reported. 

When I called our Extension entomologist Dr. Blake Layton last Monday morning, I discovered he had already received similar calls from other county Extension agents reporting gnat problems. In addition to my report of gnat issues in Warren County, Layton indicated there were buffalo gnats attacking chickens in Wilkinson, Amite and Issaquena counties, too. There are at least two pest buffalo gnat species in Mississippi — the Southern buffalo gnat, Cnephia pecuarum, and the turkey gnat, Simuliim meridionale.

Buffalo gnats can cause death to chickens and livestock by nuisance effects alone. There have been reports of deaths of birds and livestock due to heavy swarms attacking them, causing them to stampede, trampling younger animals, and sending them crashing into structures. In addition, suffocation has been blamed for some deaths in chickens due to buffalo gnats clogging the respiratory tracts. Sometimes wild birds and poultry have died from a toxic shock syndrome caused by black fly feeding. In addition to the nuisance effects, certain species of buffalo gnats may transmit various diseases, including leucocytozoonosis, a disease of turkeys, geese, ducks and sometimes chickens.

Fortunately, buffalo gnats are daytime biters and rarely venture indoors. So, one thing you can do is go inside if the gnats are biting. Providing shelters for poultry may help since the flies don’t like enclosures.  There are on-animal products labeled for biting fly control which can be applied directly to chickens. Many of these contain the active ingredient, permethrin. One example is PermectrinR spray insecticide (remember to read and follow all label directions). 

Repellents containing DEET are minimally effective against buffalo gnats. Wearing light-colored clothing may help deter the gnats. I know at least one local who claims vanilla extract keeps the gnats away. I cannot promise that works, but it does smell good. People being tormented by buffalo gnats should be encouraged by the fact that the adult flies only live 3-4 weeks and should go away during hot summer.

John C. Coccaro is county Extension director. Write to him at 1100-C Grove St., Vicksburg, MS 39180 or call 601-636-5442. E-mail him at jcoccaro@ext.msstate.edu