Bacillus thuringiensis israelensis (Bti) is a naturally occurring
soil bacterium that can effectively kill mosquito larvae present in
water. Apply in ditches, waters edge, or standing water on your property. It is one of many strains of Bacillus thuringiensis, each
having unique toxicity characteristics. Bti is very specific for
mosquitoes and black flies, and has some toxicity toward certain other
dipterans (including midges). Bti is the primary material used for
mosquito control because of its low toxicity to non-target species.
Commercially available Bti strains are sold under the trade names
Aquabac©, Teknar©, Bactimos© , and Vectobac© .
When community mosquito control is needed to reduce mosquito-borne
disease, the Department of Health favors use of larvicide applications
to the breeding source of mosquitoes. Larvicides are more effective and
less toxic than adult mosquito sprays, and the applications are unlikely
to result in human exposure.