Warming climate could bring more mosquitoes to Georgia

• Extreme drought linked to climate change can increase populations of mosquitoes carrying West Nile virus in Georgia.
• Stagnant, nutrient-rich water in unflushed storm drains creates ideal breeding grounds for mosquitoes during dry periods.
• Residents can reduce mosquito breeding by regularly emptying items that hold water, such as buckets, planters, and birdbaths.

Extreme weather events, such as intense, prolonged drought linked to climate change, can increase populations of mosquitoes in Georgia. And scientists warn that warming temperatures are driving north the mosquito breeds typically associated with environments south of the equator.

“Mosquito larvae and pupae require standing water to develop,” said Elmer Gray, an entomologist in the Department of Entomology at the University of Georgia. “In general, swamps are very dry and rivers are low. Larvae develop in nutrient-rich water, and oftentimes this occurs in storm drain systems. So when it’s dry, there’s always going to be water left in some of the pipes underground.”

Gray said the lack of rain means these systems haven’t been flushed by runoff that would normally drain from city streets after a typical rain event. Stagnant water in pipes and catch basins provides a perfect habitat for larval development.

“There are 63 species of mosquitoes,” Gray said. “At least 20 are in the Augusta area, maybe more. Georgia has a high diversity because we go from the mountains in north Georgia to the saltwater coast and then down to the Okefenokee Swamp. So we have a wide range of temperatures and habitats.”

Gray said that, from a disease standpoint, five or six species are a cause for concern.

Species in Georgia that could be problematic include the Southern house mosquito, Eastern tree hole mosquito and the Gallinipper. 

“The Asian tiger mosquito develops in containers around our yards,” he said. “When we finally get some rain, homeowners need to be vigilant about eliminating standing water.”

Tips to reduce moquito breeding

The Centers for Disease Control and Prevention, and other health agencies, recommend these tips to lessen mosquito populations:

• Once a week, empty and scrub, turn over, cover or throw out any items that hold water, such as tires, buckets, planters, toys, pools, birdbaths, flowerpot saucers, or trash containers. Mosquitoes lay eggs near water.
• Tightly cover water storage containers, such as buckets, cisterns and rain barrels, so mosquitoes cannot get inside to lay eggs.
• For containers without lids, use wire mesh with holes smaller than an adult mosquito.
• Fill tree holes to prevent water from collecting.
• Repair cracks or gaps in septic tanks.
• Cover open vents or plumbing pipes.

Mindy Kruty-Crothers, director of mosquito and vector surveillance at the Georgia Department of Public Health, said some mosquitoes that typically live south of the equator are migrating north as the climate warms.

“We’re seeing mosquitoes appear in Florida that haven’t been here before because the weather is much warmer now,” she said.

Crothers said mosquitoes are highly resistant to drying out.

“They can lay their eggs somewhere wet, and even if it dries out and they don’t hatch, the eggs can lie dormant for a long time,” she said. “I collect mosquito eggs on paper and store them in a drawer until we’re ready to hatch them for insecticide-resistance testing. A year later, I can add water and they’ll hatch.”

This reporting content is supported by a partnership with Journalism Funding Partners.

Erica Van Buren is the climate change reporter for The Augusta Chronicle, part of the USA TODAY Network. Connect with her at EVanBuren@usatodayco.com or on X: @EricaVanBuren32.