Accuweather: Above-average rainfall boosts mosquito populations across eastern U.S.

Above-average rainfall this spring and summer has already caused plenty of problems for residents in southwestern Pennsylvania, most of them flood-related.

But the problems don’t stop there: that flooding leaves behind countless pools of stagnant water, which in turn serve as a way for mosquitoes to boost their blood-sucking ranks.

Accuweather officials on Wednesday advised that mosquito activity is “two to three times higher” than normal in the eastern U.S. this summer, in large part due to the wet spring and summer the region has experienced.

The majority of the mosquito’s life-cycle is spent in water in its immature stages, according to Jim Fredericks, the chief entomologist for the National Pest Management Association.

“The mosquito life-cycle requires water, they lay their eggs in or near water, and the larvae are actually aquatic. So when there is water around, you’re going to have mosquito populations, particularly stagnant water,” Fredericks said.

The state’s West Nile Virus Control Program, a collaboration between the departments of environmental protection, health and agriculture, listed Westmoreland County as an area with an above-average risk on its most recent map of Pennsylvania’s “hot zones” for West Nile Virus, and surveillance of mosquito populations in the county is ongoing.

Allegheny County is listed as a moderate-risk area.

And while dry weather can help in some ways, it also brings mosquitoes closer to homes, where stagnant water sources can range from bird baths to clogged rain gutters or potted plants.

An upcoming change in the weather pattern may create conducive conditions for mosquito populations to grow further.

“A weekend rainstorm ahead will mark a switch to a prolonged wet pattern in the northeastern U.S.,” AccuWeather Senior Meteorologist Alex Sosnowski said. “Downpours will leave behind standing water that can create breeding grounds for mosquitoes. Be sure to check AccuWeather’s mosquito activity forecasts and Zika index before partaking in outdoor activities.”

It is hard to know exactly how long these mosquito rates will stay elevated.

“I would expect that we will continue to have a buggy summer, pretty high levels this summer and extending into the autumn,” Fredericks said.

Patrick Varine is a Tribune-Review staff writer. You can contact Patrick at 724-850-2862, pvarine@tribweb.com or via Twitter @MurrysvilleStar.