Mosquitoes ready to swarm Atlanta

Mosquitoes are about to make you miserable.

They were already out and about in metro Atlanta, but peak mosquito season has now begun and soon so will local efforts to monitor for West Nile virus. The recent bout of heavy rain will make things both better and worse: It depleted the population of the type of mosquito that can be deadly, but boosted the kind that’s simply annoying.

Dumping standing water right now — from planters, buckets, old tires and black corrugated plastic pipe — could tamp down an impending mosquito baby boom.

“Be diligent,” said Elmer Gray, an entomologist with the Cooperative Extension Service at the University of Georgia. “The conditions are right. The season is upon us, and prevention starts now.”

Rain and warm nights can add to the feeding frenzy.

Hartsfield-Jackson Atlanta International Airport got 3.90 inches of rainfall on Saturday alone, and smaller amounts on other recent days, according to Channel 2 Action News meteorologist Brian Monahan.

“We saw as much rain Thursday through Monday as we had seen all of the previous six weeks combined,” Monahan said in an email to The Atlanta Journal-Constitution.

Deluges can wash mosquito larvae out of storm drains, temporarily battering populations of the southern house mosquito, a species that has been implicated in transmitting West Nile virus, according to Gray, the entomologist. The species, which tends to bite in the morning or evenings as shadows stretch, needs periods of dry weather in addition to water for it larvae.

But rain also fills nooks and crannies around Atlanta homes, creating more opportunities for larvae of Asian Tiger mosquitoes, an aggressive biter that can harass its victims throughout the day. Typically, they grow from egg to adult in about five days.

“The foundation population is out there,” Gray said. “They are going to take advantage of the water we’ve had. They are probably going to build from here on out.”

It is too early to tell, though, whether this will turn out to be a bumper year for Georgia mosquitoes, he said. So far, it’s looking fairly typical.

As early as this week, DeKalb will be launching its annual monitoring of mosquitoes carrying West Nile virus, which the insects typically pick up from birds.

Thirty-four people in Georgia were confirmed as having West Nile virus last year. Most people infected don't feel sick. Others can get flu-like symptoms. The worst cases, though, can lead to paralysis or even death. Of two known cases in DeKalb last year, one person died, according to Juanette Willis, the arbovirus coordinator for DeKalb's Board of Health.

Willis and a band of part-timers collect thousands of mosquitoes annually, setting out boxy traps that include containers of stinky water to attract their prey.

Crews will collect at 24 locations each week through October.

They target moist locations in shadows on the edge of woods or overgrown areas. The biggest cloud of mosquitoes she ever saw mushroomed out of a corrugated plastic pipe she had kicked.

“If you see that, it stays with you,” Willis said.

Captured insects are sorted by species and counted. Many are shipped off for testing, 25 to a vial.

Last year, 82 of 468 vials came back positive for West Nile virus, Willis said.

Some concentrations of the infected insects have been found along both sides of Interstate 85 from Atlanta into Gwinnett County, she said. Willis said she suspects that’s partly because some of the neighborhoods have more tree cover, birds and aging drainage infrastructure that allows water to pool.

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