Are mosquitoes bigger and bolder lately on the First Coast?
Yes, say the experts.
“Right now, we are seeing an emergency of nuisance floodwater mosquitoes,” said Molly Clark, who works at the Anastasia Mosquito Control District, which serves St. Johns County.
Clark said in an interview Thursday that it all makes sense given the gestation time for mosquitoes to breed in standing water left behind by Hurricane Irma almost two weeks ago. She said the most opportunistic species locally, since Irma, is psorophora howardii.
“They’re big, they follow you, they’re aggressive, they bite really hard,” she described. “People are complaining that the mosquitoes are trying to get into their house as soon as they open the door.”
And, she said, they’ve been multiplying with a vengeance.
“Our trap numbers have come back very high this week,” she said. “We're doing a lot of larvae sighting, we're doing adult treatment during the day. We are out with our trucks at night, fogging.”
An all-out blitz, she says, often with all 16 of the county’s technicians in the field, sampling and spraying. Clark assured that because mosquitoes are delicate compared to some other pests, the potency and amount of chemicals needed to fight them is no threat to humans.
"It's much less than with the typical pest-control an applicator would use to treat someone's home for cockroaches for ants," she said.
One of those on the front lines is Dave Strickland, who has worked for the county about 20 years. He reminded that mosquitoes can breed in all but the tiniest amounts of standing water.
“Yeah, I’ve actually seen them in ashtrays, larvae in ashtrays,” said Strickland, who’s been doing the job about 20 years now, while checking for larvae in a swampy area near Northeast Florida Regional Airport in St. Augustine.
Dr. Mobeen Rathore, an infectious disease specialist at Wolfson Children’s Hospital, echoed the same caution.
“Anything that can gather water, turn it upside-down,” he said, pointing out examples easily missed in a typical yard.
“Fountains. You have tires, you may have any sort of container – tin containers. If the water gathers in that, mosquitoes can grow and breed in there,” Dr. Rathore detailed.
Even indoor items, he said, such as a bottle cap, can be culprits.
“For example, an aquarium that the top is not there, a mosquito can breed in that.”
Rathore did point out that, despite some of Irma’s floodwater containing sewage and other contaminants, it’s the breed of mosquito – not the cleanliness of the water in which it breeds – that dictates whether its bite transmits disease.
“The mosquito that breeds anywhere is the same mosquito, carries the same possible infections,” Dr. Rathore said. “The risk after a hurricane and flooding is more with other types of infection, cuts and bruises that can get infected.”
If there’s good news about the gigantic psorophora howardii, it’s that the species does not transmit diseases such as Zika, West Nile Virus, or Eastern Equine Encephalitis. The bad news, according to Clark, is that about ten of the roughly species that inhabit the First Coast periodically, do, especially ones that arrive in the fall.
“They are coming very shortly,” she warned.
“We could see them in the next week or so,” Clark said.
She added that an aerial treatment application that was scheduled for Thursday night in St. Johns County has been delayed, probably for a few days. Clark emphasized that in addition to municipal efforts, people must take individual precautions as well.
She urged that people use and often re-apply repellents containing DEET. For those who prefer a more organic - if less effective - solution, she mentioned oil of lemon eucalyptus or soybean oil. She also encouraged that people stay indoors before dawn and after dusk, pointing out that wardrobe choice can make a difference at any time of day.
"We recommend loose-fitting, light-colored clothing," Clark said. "Long-sleeved shirts and long pants will help reduce the ability of mosquitoes to actually bite you."