By Teahna Ratliff

It’s that time of year again, when people are being bitten by BITING FLIES! There are 35 species of different flies here in Florida. Deer flies, horse flies, and stable flies deliver a painful bite to large mammals, including people. But, the most common and dreaded fly that people know here in South Walton, is the Yellow Fly. Many of these flies have similar life cycles and behaviors. Florida has the perfect habitat for these flies with the mixture of wetlands and high populations of readily available meals from animals and people.
These flies lay eggs every year in the soil around water. Once a rain event happens the eggs hatch and drop a larva into the water. Larvae are the immature form of an insect. Examples would include maggots, caterpillars, or grubs. They stay in the larvae stage through wintertime, then wiggle their way to more muddy areas to pupate (cocoon stage). This allows for the perfect time for adults to emerge in the spring. Their life cycle takes about a year to complete. This is how we know when “Yellow fly season” is upon us. Yellow flies are mainly active between May through October, but from traps and residential complaints, we see them as early as April and end by August in South Walton County.

As adults, these flies can normally be found waiting in shaded areas- such as tree lines and bushes waiting for a blood meal to pass. Like mosquitoes, females are the only ones that bite. They need protein in the blood to produce their eggs. While the males mainly feed on pollen, females determine meals through eye sight, but carbon dioxide also plays a part. These flies are mainly active for a few hours after sunrise and a few hours before sunset. Yellow flies are not known to pass any diseases but do deliver a painful bite that some people may have an allergic reaction to.

As far as treating these pesky biters, mosquito control does NOT spray for yellow flies. Although there have been conflicting resources stating the products we use can be effective in yellow fly control. We do NOT spray during the day to protect pollinators, such as bees and butterflies. Also, our spray size is designed for the size of a mosquito’s body, not a robust fly. As an individual, the best practices are using repellent (with DEET) and wearing long sleeves and light colors while outside. There are also yellow fly sticky traps that resemble a large mammal. Yellow flies are attracted to dark colors and moving objects. The yellow fly traps hang in the tree line (away from porches or where kids play). The female yellow fly sees a moving object and goes to land for a bite, then gets stuck.

South Walton County Mosquito Control District supplies 1 yellow fly kit per primary resident in their primary home. The resident must reside south of the bay between Bay County and Okaloosa County line and must pre-register on the South Walton County Mosquito Control website before arriving. South Walton County Mosquito Control District will be hosting an event on Saturday May 20, 2023, from 9am-1pm, where residents can drive through to pick up their one free kit. For further information, please go to their website https://www.southwaltonmosquitocontrol.org/yellow-fly-kit-request or call (850)267-2112.