Mosquito control to spray Upper Key Largo, Ocean Reef Tuesday morning

Upper Key Largo, Middle Key Largo and Ocean Reef will be under an aerial naled treatment Tuesday morning, with helicopters scheduled to spray from 6 to 9:30 a.m. over mile markers 98 through 106.5. Florida Keys Mosquito Control District says the mission is aimed at a large area with high adult mosquito populations, and it will go up only if weather conditions are optimal.

The district says aerial adulticide missions are part of its integrated pest management program and that naled is a non-persistent insecticide that breaks down rapidly when applied as directed. For these runs, the district uses one of its Airbus H125 helicopters equipped with ULV spray systems, and its posted schedule says all aerial adulticide missions fall between 6:30 a.m. and 9:30 a.m.

The spray comes as Monroe County continues to treat the Key Largo dengue response as a mosquito-borne illness issue, not a person-to-person threat. County guidance says emergency management works with the Florida Department of Health in Monroe County and the mosquito control district when there is an outbreak, and that the likely source of the Key Largo cases was a traveler or resident who had returned from a dengue-endemic area and was bitten by an Aedes aegypti mosquito.

County FAQs say there are no local, state or federal advisories discouraging travel to Key Largo or anywhere else in the Florida Keys. Officials also note that dengue has year-round activity in the Caribbean and in South and Central America, which is why mosquito control and public-health monitoring stay closely linked across the Keys.

For residents in the spray zone, the clearest steps are to eliminate standing water and use mosquito repellents containing DEET, picaridin or oil of lemon eucalyptus. The broader public-safety picture is hard to miss: the U.S. Centers for Disease Control and Prevention reported 3,798 dengue cases nationwide in 2024, with 97.2% tied to travel and 2.8% locally acquired. Florida had the highest incidence among states, and 85 locally acquired cases were recorded across 10 counties.

The district’s early-morning helicopter mission is meant to knock down adult mosquitoes over a broad swath of Upper and Middle Key Largo before the day heats up, part of a short-lived chemical strike aimed at keeping the outbreak from spreading further.