Southwest Florida’s buzzy season takes flight
With the rainy season officially upon Southwest Florida, have you noticed yourself swatting those annoying, biting, teensy insects away more often?
While mosquitoes are present in Lee County all year, when the rain comes, the larvae develop, causing an explosion of literal billions of insects to roam across the region.
Lee County Mosquito Control District officials say they’ve been working at a fervent pace to mitigate the 54 different species of mosquitoes that call the county home.
“We never stop spraying,” said LCMCD Communications Director Jen McBride. “Mosquito season is year-round in Southwest Florida. Typically we think of (the height of) mosquito season as the start of rainy season.
McBride said the start to rain season this year was very different from last year in that it started off very significantly, whereas last year was more of a gradual start.
“We do have a lot of mosquitos this season, and that has to do with our dry winter,” she said. “All it took was that egg bank to accumulate over a dry winter. We still have mosquitoes out there. They’re still laying eggs. They’re laying eggs in places where until we get a high tide or a lot of rain, they’re not going to come off. That rainy week we just experienced started things very quickly.”
Out of the myriad of species of mosquitoes in the county, McBride said the one that typically starts the year off and sticks around all year is the salt marsh mosquito.
They usually lay eggs around the coastal areas of Sanibel, Captiva — anywhere along the coast.
“The one thing that people don’t realize is how close they are to salt marsh areas,” McBride said. “These species of mosquitoes will fly anywhere to 20 miles away for a blood meal. So we’re living next to this tremendous, really prolific growing area for salt marsh mosquitoes.”
LCMCD officials are getting an influx in calls currently, and McBride said other agencies throughout the region are experiencing the same thing.
Where LCMCD sprays is entirely based on activity.
“We go where the mosquitos are,” McBride said.
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According to LCMCD officials, treatment plans are scheduled on a day-to-day basis. The mapping system that can be viewed online is where the district plans to treat, but it is not always accurate for determining if an area was treated. If an area is scheduled and it is not treated due to weather or technical difficulties, it will not be removed from the system and will continue to show as a planned treatment area.
“People call in and ask what our spray schedule is. We don’t have a spray schedule. Where we spray is based on mosquito activity. We have to have data, we have to have proof that there is a mosquito issue.”
Residents often worry about how the district’s spray impacts pollinators and other insects. McBride said the treatment they use does not cause harm.
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“Our spray does not impact the butterflies and bees,” she said. “All of our treatments are EPA approved which also includes not harming non-target insects. Also, the adulticiding – treating the air column where mosquitoes fly — is done in the evening when those insects are not foraging. There’s lots of research to support it does not harm non-target insects. We have great relationships with local beekeepers and butterfly gardens. They get notification of our adultiiciding spray so if they want can take extra precautions to protect their hives. “
What defines a ‘mosquito issue?’
McBride said it depends on the area. The district knows those salt marsh areas will have a higher number of mosquitos present. Once a threshold gets past “normal” mosquito activity, the district will treat the area.
LCMDC looks at dip count, where they test water to see the number of larvae present in an area. They look at the number of adult mosquitoes in an area, and take into account where the volume of calls are coming from.
Weather also plays a role in treatment. When it rains, or the wind is too strong, LCMCD is unable to go out and treat.
LCMCD has a boots-on-the-ground team that goes out and surveys communities where calls are coming from to see what the data tells them.
“We have to go out and collect data,” McBride said. “Sometimes it might be a no-see-um issue. It might be the start of the season and people just forget what it’s like to be back in mosquito season. We have to make sure we have the surveillance and the data to justify any type of treatment, as it should be. We’ve become really smart about treating mosquitoes and taking care of our environment, too.”
McBride said 75% of the district’s operations is trying to catch the mosquito at the larvae stage, and to catch them before they become biting adults. Currently, that’s an easier-said-than-done task with the recent development. It takes five to seven days from eggs being laid to have adult mosquitos added to the population.
“You get those adult issues when we’re not able to treat due to weather conditions,” McBride said.
Other than spray treatment, LCMCD has Gambusia fish, or “mosquitofish,” where fish that eat mosquito larvae are deployed in areas where other predators do not exist.
In the Edison area, the district has been implementing the sterile insect technique. The SIT is a method that is used to reduce insect populations. It involves releasing lab-reared sterilized insects to mate with the wild population to reduce the targeted species.
According to district officials, they lab-rear Aedes aegypti mosquitoes which are commonly found in urban neighborhoods. Once at the pupae life stage, the district X-rays the males which causes sterilization. These sterile adult male mosquitoes are then released into the environment to mate with wild females. The eggs laid by female mosquitoes will not hatch, which will reduce the mosquito population. For population reduction, LCMCD releases sterile male mosquitoes, which do not bite. Only female mosquitoes bite.
Mosquito-borne disease surveillance program
LCMCD has a proactive, year-round mosquito-borne disease surveillance program made up of four parts. The first part is sentinel chicken surveillance. Officials state this portion uses the appearance of mosquito-borne disease in chickens strategically placed around the county to monitor the transmission of disease among the disease’s reservoir host, birds.
“We’re lucky enough to have in-house testing where we’ve got our biologists testing the chicken’s blood for West Nile and others.”
The second part of the program is specialized adult mosquito trapping performed with CDC light traps to monitor the level of the vector mosquito. The third part is the analysis of the collected vector mosquito to detect the presence of viral RNA.
“This data indicates the presence of infected or potentially infected mosquitoes,” state LCMCD officials.
The final part is human investigation, which involves determining when and where a disease was contracted. Contraction could be outside the neighborhood of the victim or outside the country.
“When a mosquito borne disease is detected in a sentinel chicken, mosquito or human, the district responds immediately to control adult mosquitoes in the vicinity of the disease detection to try and prevent the further spread of the disease by mosquitoes,” district officials state.
LCMCD uses both fixed wing and rotary-wing aircraft in mosquito control operations. During daylight hours for inspections and larviciding purposes, an Airbus H125 helicopter is utilized. Fixed wing and rotor wing aircraft are used for the district’s nighttime aerial adulticiding program. These missions are carried out between sunset and 2 a.m., when adult mosquitoes are most active and likely to be exposed to the very small droplets produced by the ultra-low volume spray system. The district also uses drones to get to small areas other aircraft can’t treat. Other district inventory includes field inspection vehicles, surveillance vehicles, spray vehicles, lawn equipment, aircraft tugs, marine vessels and heavy machinery.
So, what’s the best way to keep away from mosquitoes this summer?
“The biggest thing to know is that we started this season off with a bang,” McBride said. “It takes a couple weeks to get them under control because we had that sudden start to the rain season. We’re here doing our job.”
Wearing long sleeves and long pants, despite the heat, is always a good way to combat mosquito bites, as is using an EPA-approved DEET spray or wipe.
For more information on the district, or to make a service call, visit lcmcd.com.