Applying Aquatic Pesticide to Westlake

Westlake Management Association has contracted with Clean Lakes, Inc. to apply a larvicide called Vectobac to Westlake. The active ingredient in Vectobac is a common bacteria strain called bacillus thuringiensis israelis or BTI. BTI is labeled for the control of aquatic midge larvae. Product names are Vectobac 12AS, Vectobac G and Vectobac WDG. BTI is highly target specific and has been found to have significant effects only on mosquito and aquatic midge larvae and closely related insects such as black flies. . BTI has no measureable toxicity to vertebrates and is classified by the US EPA as “Practically Non-Toxic”. It comes with a Caution label.

These applications will be performed lake wide on Westlake between the months of April and October in order to keep midge populations under nuisance levels. Applications are to the entire water volume of Westlake, and are designed to maintain an effective control level throughout the water column. Post application, BTI biodegrades in 48-72 hours and leaves no detectable residue in the water. There are no post-application water use restrictions in regard to current allowable uses of Westlake, i.e. fishing and boating.

BTI contains naturally produced bacterial proteins generally regarded as environmentally safe. It leaves no residues and is quickly biodegraded. At the application rates used for midge control, BTI is unlikely to have any measureable effect on water quality. There are no established standards, tolerances or EPA approved tests related to BTI. Other naturally occurring strains of this bacterium are commonly found in aquatic habitats.