Larviciding: Treating larvae in their habitats with mosquito-specific products

Larvicides: Manatee County’s Front-Line Defense Against Mosquitoes

The Manatee County Mosquito Control District prefers the use of larvicides (over adulticides) as our front-line mosquito control approach as larvicide products are more mosquito-specific and environment friendly. The primary product used, a bacteria-derived toxin called Bti, is mosquito-larvae-specific, requiring digestion within the larval gut to become active, thus having no impact on other aquatic organisms including fish and other insect species. Larviciding targets the aquatic stages of mosquitoes while they are still concentrated, immobile and highly susceptible. We use trucks to spray roadside ditches and low-areas where mosquitoes breed before they can emerge as adults. Sometimes we cannot access mosquito breeding sites with trucks so the public may occasionally see our staff using backpacks or handheld sprayers.

Aerial Larvicide Applications: Helicopter Missions to Tackle Remote Breeding Grounds

We also utilize our helicopters for larvicide applications over larger, remote wetland habitats. These missions occur in the daytime (unlike night missions for spraying adult mosquitoes) and typically apply a granular bacterial larvicide(“Bti”) that falls directly under the spray pattern of the aircraft (no significant “drift”). On rare occasion we sometimes spray with liquid larvicides in “open” habitats when large raindrop sized droplets can reach the target below. And we occasionally use other EPA-approved larvicides such as methoprene when appropriate or field conditions dictate an alternative to Bti.

Challenges in Controlling “Freshwater” Mosquitoes: Constraints of Larviciding Methods

The “freshwater” mosquito species found in the eastern part of the county are not easily controlled through these larviciding methods. They are not typically concentrated in clearly definable habitats and are often in areas too vast to be effectively treated in the limited time available (3-4 days).


Get In Touch

Manatee County Mosquito Control

1420 28th Ave East
Ellenton, FL 34222