How Does Mosquito Control Work for a Florida Yard?

Mosquitoes lay their eggs in or near water, and the young, called larvae, live in the water until they become biting adults. Pinellas County says mosquitoes can develop in any water that stands more than four days. The Florida Department of Health says as little as a bottle cap of water standing more than a week is enough.

UF/IFAS lists common places around homes:

• Plant saucers, bird baths, buckets, toys, trash cans and old tires.
• Clogged gutters, roof debris, and boat or car covers that hold a puddle.
• Pet dishes, poorly kept pools and low spots that hold water after rain.
• Bromeliads, which hold water in the cups where their leaves meet.
• Tree holes, and fallen palm fronds that catch rain.

Tip and toss is a phrase some Florida mosquito programs use for source reduction: tip out anything holding water and toss anything you do not need. The Florida Department of Health asks residents to empty or cover anything that could hold water at least once a week. UF/IFAS calls source reduction the most important thing a homeowner can do.

• Turn over buckets, wheelbarrows, kiddie pools and unused pots.
• Change bird bath water weekly and pet water daily, as Pinellas County suggests.
• Store small boats upside down and keep gutters clean.
• Cover rain barrels tightly, or use fine mesh smaller than a mosquito.
• For water you cannot dump, like a rain barrel or a decorative pond, products with Bti, a bacteria that kills mosquito larvae, are an option. UF/IFAS says Bti does not harm butterflies, bees, fish, frogs or other non-target species.

Bromeliads are one of the harder sources in a Florida yard. UF/IFAS researchers recommend flushing the cups with a strong jet from the hose at least weekly, and Pinellas County suggests twice a week. Larvicide granules made for this use are another option. If you are adding plants, UF/IFAS suggests types with small or no central cups, such as Cryptanthus.

Tree holes are cavities where a branch died back or bark was damaged and rot set in. The CDC suggests filling tree holes so they cannot hold water. On a living tree, that is a decision for an arborist, not a bag of concrete. Filling a cavity does not stop decay, and it makes the tree harder to assess later. A hole that holds water can also be a sign of decay inside the trunk. Before you fill one, have an arborist look at it. Our page on tree defects explains what we look for.

UF/IFAS counts more than 80 mosquito species in Florida. A handful do most of the biting around homes here.

• Asian tiger mosquito (Aedes albopictus) and yellow fever mosquito (Aedes aegypti). Pinellas County describes both as common in the county. They breed in small containers, tree holes and bromeliads, and can spread dengue, chikungunya and Zika. UF/IFAS describes the tiger mosquito as a daytime biter, with peaks in early morning and late afternoon.
• Southern house mosquito (Culex quinquefasciatus). Larvae favor water with a lot of organic matter. UF/IFAS lists it as a carrier of West Nile and St. Louis encephalitis viruses.
• Black salt marsh mosquito (Aedes taeniorhynchus). It breeds in salt marshes, is found in every Florida county, and is a strong flier. UF/IFAS calls it a major pest in summer and early fall.

UF/IFAS notes that some species travel only about 500 feet from where they hatch, while others move dozens of miles. The strong-flying salt marsh mosquitoes help explain why a waterfront yard can have bites even when there is no standing water on the property.

A barrier treatment is an insecticide applied to the shrubs, ground cover and shady spots where adult mosquitoes rest during the day. The CDC describes adult mosquitoes resting in dark, humid places. Treating those spots kills adults that land there.

• What it does: lowers the number of adults resting in the treated areas for a period of time. One UF/IFAS Extension article puts chemical sprays at about 1 to 3 weeks, depending on weather and product.
• What it does not do: kill larvae in water it does not reach, stop mosquitoes from flying in from a neighbor’s yard or a marsh, or replace tip and toss.
• What to watch: UF/IFAS points out that adult mosquito insecticides are broad spectrum, meaning they are not specific to mosquitoes, and advises applying them when other insects are less active. Repeated use can also lead to resistance.

Pinellas County Mosquito Control serves the whole county, including all 24 municipalities. It traps mosquitoes to watch populations, keeps sentinel chickens at eight sites to watch for viruses, treats breeding water with larvicides by truck and helicopter, and clears blocked ditches. The county is divided into 11 zones, each with its own technician.

Residents can request service at (727) 464-7503 or through the county’s mosquito control page. A technician tries to identify the species and find where it is breeding, and may dump water, add mosquitofish or apply larvicide. The county says treating adult mosquitoes gives only temporary relief.

Florida has had locally acquired dengue, meaning cases caught from mosquitoes here rather than while traveling. The Florida Department of Health reported 87 such cases in 10 counties in 2024. When virus activity is high, the county may change which requests it can take, so check the county page and its treatment map for the current status.

The county works at the neighborhood scale. A private service works on your property. O’Neil’s Land Care, part of the same company, handles mosquito control under Florida pest control licensing, and our mosquito control service page lays out the approach: find and fix breeding sites, treat water with larvicides, add habitat for predators like bats and dragonflies, and use targeted adult treatments on resting areas.

No service can eliminate every mosquito. What a good program can do is cut the number in your yard to where you can use it again. Adding a repellent with DEET, picaridin, IR3535 or oil of lemon eucalyptus, all on the CDC’s list of EPA-registered repellent ingredients, still helps. A UF/IFAS Extension agent reports citronella candles and bug zappers have not been shown to work.