Florence rainwaters lead to mosquito breeding grounds

Robert Phillips walked onto the porch of his Eastover home to water flowers Tuesday night and was almost immediately swarmed by aggressive mosquitoes.

Worse yet, Phillips said, one type of mosquito was among the biggest he's ever seen — at least 3/8 of an inch long.

“A bad science fiction movie,” he said. "They were inundating me, and one landed on me. It was like a small blackbird. I told my wife, 'Gosh, look at the size of this thing.' I told her that I guess I'm going to have to use a shotgun on these things if they get any bigger.”

Phillips is among many Cumberland County residents who are reporting a mosquito outbreak unlike any they have ever experienced since the remnants of Hurricane Florence moved through the area. The storm's rainwater − nearly 20 inches in some areas of the county − has created breeding grounds for large and aggressive mosquitoes.

Mosquito experts say floodwater has caused eggs for species such as the large Psorophora ciliata mosquito to hatch. The mosquito, which is two to three times larger than a regular mosquito by weight, has been referred to as the “gallinipper” or “shaggy-legged gallinipper” because of its tendency for aggressive behavior. Psorophora ciliata is associated with other floodwater mosquitoes. The mosquitoes often lay their eggs in low-lying areas with damp soil and grassy overgrowth. The eggs lie dormant in dry weather and then hatch following heavy rains or flooding, often producing extremely large numbers of adult mosquitoes.

Michael Reiskind, an entomology professor at North Carolina State University, said the standing water from the hurricane is causing more eggs to hatch for a wide range of mosquito species.

“There are 61 species in North Carolina that are boom or bust,” he said, adding that they are looking for these type of storm events to hatch.

“In a normal year, in the absence of a hurricane or significant rainfall, most of those eggs would probably die before ever getting a chance to hatch,” Reiskind said. “But with all the water that has come up, they have gotten a chance to hatch. In some cases, the eggs may live one year.”

He said the mosquitoes that are being hatched in floodwaters aren't new species, and they weren't blown in from other areas of the state during the storm. He said the species seen now just aren't as noticeable during dry weather because fewer are around.

“The female has a strategy of laying lots and lots of eggs. The eggs are good at surviving, kind of riding it out and waiting for a big flood,” Reiskind said. “When the flood comes, we get many many billions of them. The good news is that a lot of mosquitoes we are seeing in high numbers after an event like Florence are not transmitting a lot of diseases."

Reiskind said spraying insecticide is a fairly effective way of reducing mosquitoes. But he said it's more difficult to kill them when they are clustered in large numbers, as they are now.

Sally Shutt, an assistant county manager, said in email that the county is “actively engaged in evaluating options for mosquito spraying and putting together a process to get quotes from vendors.”

Late Wednesday, Gov. Roy Cooper said $4 million will go to mosquito control in counties under the Florence disaster declaration, including Cumberland and neighboring counties, plus Scotland and Lee. The money will help counties provide eradication.

Shirley Chao, a professor of biology at Fayetteville State University, said she's seen a couple of the Psorophora ciliata mosquitoes since the storm passed through.

“They are a lot bigger than the normal mosquito. Their larvae is a lot bigger. They are like bullies in water and feed on other mosquitoes,” she said. “I think some people thought they'd be beneficial because they eat other mosquito larvae that cause diseases. But they will fly around and bite you and suck your blood, so they're just as much of a pest as another mosquito. But the bite is a lot more painful.”

Mosquitoes can emerge days to weeks after flooding or heavy rains, and they can be more than a nuisance. Some can carry viruses.

To protect yourself from exposure, Rodney Jenkins, interim director of the county's Environmental Health Department, said if your body temperature can handle it, cover your arms and legs. The best type of repellents are those that contain DEET, he said.

“We strongly encourage everyone to use the tip-and-toss method for eliminating standing water and mosquito breeding grounds that may be in empty trash cans or tires,” Jenkins said.

The Environmental Health Department, at 1235 Ramsey St., is offering free pest control discs — or donuts as they are often called — to eliminate mosquitoes. The discs can be dropped into standing water that may be found in yards or ponds.

On the brighter side, the mosquito infestation should subside when the weather becomes cool and dry.

Staff writer John Henderson can be reached at jhenderson@fayobserver.com or 910-486-3596. Correspondent Keyona Smith can be reached at 910-323-4848.

Keyona Smith contributed to this report.

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