For more than ten years the City has used a larvicide to control mosquito populations as needed. Beginning in May of 2003, in response to the threat of West Nile Virus, the City began using this larvicide in all potential mosquito breeding sites throughout the city. The larvicide is distributed monthly from May through September at these locations.
The Bti (Bacillus thuringiensis israelensis) bacteria specifically attack the larval stage of mosquitoes. Bti is currently the best method available to kill mosquitoes before they have a chance to reproduce. Bti becomes active upon contact with water and is effective for 30 days once it is deposited in water. If the water dries up, Bti is still effective once rewetted. It does not affect animals or the physical environment in which it is used.
Bti dunks are available at hardware and garden stores.
Please note that common sense should apply even in this low risk period. Using Deet (according to labeled instructions) and wearing long sleeves and pants are wise practices, particularly when outdoors during dawn and dusk. Draining and emptying containers around the yard are prudent mosquito control practices. Many of those infected with WNV were bitten in their own yards.
More information on West Nile Virus
