Florida mosquito control teams have had their hands full this season in part due to a population explosion all over the state, as well as an uptick in locally acquired cases of dengue, a mosquito-borne disease, in Brevard County.
The big buzz this summer comes from a population boom of saltwater marsh mosquitoes, known scientifically as Aedes taeniorhynchus. Experts say it's the worst population surge in a decade.
“When you have a year as bad as you have this year, combined with the special winds and migratory behavior of the salt marsh mosquitoes, it can get really bad,” said Kiera Lucas, deputy executive director of Collier County Mosquito Control.
This summer, billions of saltwater marsh mosquitoes hatched after a very wet season in late May and June, which provided ideal breeding conditions. Populations have boomed all over the state as the marsh-dweller typically breeds in brackish waters of mangroves and swamps. The mosquito can also travel up to 40 miles from its breeding ground.
The good news is that the saltwater marsh mosquito doesn’t carry human diseases, but there are still reasons to be concerned. The marsh mosquito is considered a nuisance, a daytime biter, and very aggressive. According to the FMCA, up to 150 of these mosquitoes can attack a person in less than a minute.
“Local physicians in Collier County say that there are people who are coming into the doctor's office with severe allergic reactions to these mosquitoes,” Lucas said.
The mosquito also represents potential problems for pets, said Eva Buckner, a medical entomologist at the University of Florida.
“We do have a concern for our animals, with them being able to vector heartworm that can make pets sick,” Buckner said.
In Brevard County, the control team has been working to manage the spread of the saltwater marsh mosquito by pumping and maintaining water levels within marshes and deploying mosquito-eating fish into popular breeding grounds.
“We were able to distribute at least 150,000 mosquito fish. A lot of that goes into the salt marsh areas as we're filling up those impoundments,” said Joseph Faella, director of Brevard Mosquito Control. “But we're also distributing them to the public so they can put them in their abandoned swimming pools, rain barrels, and larger containers that just can't be dumped.”
In addition to dealing with large saltwater marsh mosquitoes, Brevard County has been tracking down mosquitoes carrying dengue, a mosquito-borne disease that can cause fever and painful body aches.
The disease is not endemic in Florida, but Florida recorded eight locally acquired cases this year, four of them occurring in Brevard County last week, bringing the county’s total up to six.
Dengue is carried by a different mosquito species, the Aedes aegypti. Last year, the state experienced a huge surge in travel-associated cases of dengue – 911 compared to the 214 cases experts expected.
Numbers are much lower this year at 122, so far. In Brevard, there were two imported cases. Mosquito Control is working to make sure that the local cases don’t rise anymore than they have. What’s tricky, Faella said, is juggling the efforts to reduce population numbers in both saltwater marsh mosquitoes and dengue-carrying mosquitoes. The former can travel 40 miles, whereas the latter doesn’t travel nearly as far.
“They may not even fly 1000 feet from the source. So you could imagine, this is a nightmare for mosquito control. We're looking at the broad scale where you have these salt marsh mosquitoes flying 25 plus miles,” Faella said. “You can kind of trace that. You know where the sources are. The complaints over here are that the wind blew them over… to every nook and cranny.”
Faella said the sliding scale of distance between the two types of mosquitoes “makes a big difference.”
Brevard has inspectors in suspected dengue-spreader areas seven days a week and has increased the number of traps it uses.
For residents, mosquito control recommends that those who live in mosquito-prone areas dump any standing water in their yard, avoid being outside during dusk and dawn, and wear long, breathable sleeves when outside.
