How do you stop a mosquito invasion in Miami after the rains and floods? Take a look

Heavy rain and flooding brought misery to parts of South Florida in June. That misery may not be over yet.

Here come the mosquitoes.

While combat teams and health officials haven’t issued advisories yet, they are bracing themselves for a possible onslaught. And people who work outside are already feeling it.

Darren Grusky is quick to offer his landscaping crew bug spray as they work near the water in Northeast Miami-Dade.

The landscapers — wearing long-sleeve shirts and gaiters for sun and mosquito protection — are used to seeing a lot of mosquitoes during the summer. But June’s nearly week-long downpour and flooding has “definitely stirred up a lot” of the bloodsuckers, especially near mangroves, said Grusky, owner of TLC of South Florida.

More pesky mosquitoes could soon be buzzing around neighborhoods following the soaking.

Miami-Dade County’s mosquito control unit expects to see an influx of 311 calls requesting help with the insects in coming days.

And now that it’s in the middle of peak mosquito season, inspectors have already increased spraying to control the swarms.

Female mosquitoes suck blood and leave itchy bites. They can also transmit diseases such as dengue and West Nile.

Mosquitoes lay eggs in standing water, which is why the county is urging residents to drain and cover any still water near their home.

“Mosquito control is important for the safety and health of our community and our residents, making sure that we can protect and eradicate any viruses or diseases that may be out there,” said Aneisha Daniel, director for Miami-Dade County’s Department of Solid Waste Management, which oversees the county’s mosquito control effort.

While swarms can be hard to predict, the county is ready for clusters in coming weeks, said Dr. John-Paul Mutebi, division director of Miami-Dade’s Mosquito Control, based in Doral. Miami-Dade has been under a mosquito-borne illness alert since 2023 after officials confirmed locally acquired dengue cases.

While mosquitoes are common year-round, Miami-Dade’s official mosquito season mirrors hurricane season, and runs from June through November, according to Mutebi.

More than 300 mosquito traps across Miami-Dade

Hundreds of traps are set up across the county to help track and identify how many — and what type of — mosquitoes are flying around in our neighborhoods.

The trapped insects are taken to Mosquito Control’s Doral base. They’re counted and analyzed for characteristics, including markings, wing patterns and mouth-part lengths, to determine their species. They are also screened for viruses.

A magnified image of mosquito larvae at the Miami-Dade County Mosquito Control headquarters in Doral, FL.
A magnified image of mosquito larvae at the Miami-Dade County Mosquito Control headquarters in Doral, FL.

Mosquito species in Miami-Dade

Some mosquitoes are just pests. Others can carry disease like dengue, West Nile and Zika. Of the 49 known species in Miami-Dade County, only a few are considered nuisances to humans, according to mosquito inspectors. One of the species that concerns county officials most is Aedes aegypti, or yellow fever mosquito, which can be found across Miami-Dade and can spread Zika, dengue and yellow fever.

So far, Florida has recorded 222 travel-related cases of dengue in 2024, with Miami-Dade leading the way. The county has confirmed 95 travel-related cases of dengue this year, about 43% of the state’s known cases, according to Florida’s most recent surveillance data.

The U.S. Centers for Disease Control and Prevention has issued mosquito-born illness travel notices for several countries, including Cuba, Colombia, Turks and Caicos, Costa Rica and Nicaragua.

The county’s goal is to control the mosquito population, not eradicate it. Aside from being annoying, mosquitoes do have a purpose in South Florida’s ecosystem. They’re food for birds, fish and spiders. And they pollinate plants.

Mosquitoes are “part of tropical living,” said gardener Michael Foster, owner of The Green Standard.

He has noticed more mosquitoes around, a normal sight in summer. He can tell by how many orb weaver spiders he recently saw in a client’s rose garden. Orb spiders love eating mosquitoes.

How does Miami-Dade handle mosquito invasions?

Knowing population, gender and species information can help scientists identify hot-spot areas in the county.

Depending on what the mosquito experts are seeing, they could work with the health department to issue an alert or advisory to warn residents and also create more targeted pesticide plans to reduce the swarming bloodsuckers, and decrease the spread risk of mosquito-born illnesses.

Depending on the infestation size, the county will use truck-mounted sprayers called Buffalo Turbines, have workers manually spray larvicide and adulticide treatments, or use aerial adulticiding.

Tips to reduce mosquito bites

“For a guy working outside,” mosquitoes are “just another day in paradise,” said Grusky, the landscaper.

Still, there are steps people can take to reduce mosquito bites at home and while having fun in the sun.

Here are tips:

Wear EPA-approved long-sleeve shirts if planning to be outside. And wear pants and socks, too. This may sound blasphemous, especially for those who want to get a tan or were planning to have a “hot girl summer.” But if you want to reduce a risk of a bite, leave the shorts, tanks and sandals at home. And make sure to drink lots of water and avoid being out in the sun during the hottest time of the day. You don’t want to get heat exhaustion or another heat-related illness.

Use EPA-registered mosquito repellents. The repellents should have DEET, picaridin, oil of lemon eucalyptus, or IR-3535.

Clean out rain gutters. You don’t want the gutters clogged with branches and other debris that could make it easier for rain to pool. Check containers, pots, buckets, toys, plastic covers and other items in and around your home to make sure there’s no standing water too. Remember, standing water is a mosquito’s breeding ground.

Change the water in bird baths, fountains, wading pools and potted plant trays at least once a week, according to the EPA. And if you have a swimming pool, make sure to keep the water treated and circulating.

Replace outdoor lights with yellow “bug lights.” These lights are not repellents, but they tend to attract fewer mosquitoes, according to the EPA.