By Elmer Gray – UGA College of Agricultural & Environmental Sciences/UGA Cooperative Extension
Cooler weather may be upon us, but as we open windows and head outside, it is important to remember that we are still in mosquito season.
Recent rains have filled all of the containers, cracks and crevices that can hold water around our homes and neighborhoods. While working around my yard, I have found mosquito larvae in the bird bath, a garbage can lid and in the rim of a recycling container. With just a few more warm days, I would have had a significant emergence around my home. As a University of Georgia Cooperative Extension expert in mosquito suppression, if it can happen in my yard, it can happen to anyone.
The easiest, most efficient and effective way to minimize mosquito populations is to eliminate all forms of standing water.
Mosquitoes require standing water for their larval and pupal stages to develop. The female mosquito will deposit eggs on the surface of the water or in areas that will later become wet, like moist bottomland soils or the sides of a bucket or tire.
The larvae, commonly called “wigglers,” emerge from the eggs and progress through four stages, or “instars.” The larvae are filter feeders and grazers, so the more algae and other matter growing in the water and on the surface of their larval habitat the better.
The larval stage can be five to six days, but will typically take longer, particularly as nighttime temperatures become cooler. The fourth instar larvae will molt into the pupal stage. The pupae, commonly called “tumbler,” is a non-feeding stage. This is a period of transition for the mosquito as it changes from an aquatic stage to a terrestrial stage and the adult mosquito — actually a type of fly — emerges from the water.
Emerging mosquitoes require still water where they can rest on the water’s surface and surrounding vegetation to allow their wings and body to harden. Once the mosquito’s integument, or “skin,” hardens they will fly off in search of blood and sugar meals. It’s important to remember that only the female mosquito bites. Most species — there are 63 in Georgia — require a blood meal to stimulate and sustain egg development. This is when mosquitoes become pests.
Whether it’s just nuisance biting behavior or the mosquitos are transmitting disease-causing pathogens, precautions should be taken. So far, 2022 hasn’t been too bad for disease transmission in Georgia with only five reported cases of West Nile virus. However, mosquitoes infected with the West Nile virus have been found in several counties, including most of metro Atlanta, so it’s too soon to drop our guard. Historically, the transition from summer to fall is a period of peak West Nile transmission.
With temperatures moderating and endless outdoor activities ongoing it’s wise to take precautions. One of the best things to do is eliminating all standing water around the home, paying particular attention to trays under plants, any kind of plastic containers or toys, tarps, boats, tires, drainage pipes, gutters and downspouts. Wearing pants and long sleeves in light-colored, loose-fitting clothing and using an EPA-approved repellent on exposed skin are very effective in preventing mosquito bites. Adults should apply repellent to children and it is always important to follow the label instructions.
Lastly, residents should make sure all screens are in place and in good condition to prevent mosquitoes from getting into our homes as temperatures cool and we open windows again. Prevention can go a long way in avoiding mosquitoes around our homes and neighborhoods.
Elmer Gray is a Cooperative Extension entomologist with the University of Georgia College of Agricultural and Environmental Sciences.