A Mosquito Dunk® looks like a small, beige donut which floats on
standing water. As the Dunk® slowly dissolves, it releases a bacterium
which is toxic to all species of mosquito larvae. The active ingredient
in Mosquito Dunks® is Bacillus thuringiensis subspecies israelensis
(Bti). Bti is a bacterium that is deadly to mosquito larvae but harmless
to other living things. Just float a biodegradable Mosquito Dunk® in
water troughs, koi ponds, birdbaths, rain barrels, animal watering
troughs, elevator shafts, or any place where water collects and remains
for periods of time. While floating, a Mosquito Dunk® slowly releases a
long-term biological mosquito larvicide at the water’s surface. This
larvicide gradually settles in the water, and while it travels through
the water it is eaten by the mosquito larvae growing there. When female
mosquitoes lay their eggs in standing water treated with a Mosquito
Dunk®, the larvae will hatch and begin to eat the Bti. The Bti will kill
the mosquito larvae before they can grow up to become biting and
disease-spreading adults. Each Mosquito Dunk® will effectively treat 100
square feet of surface water for 30 days or more. For less water, a
portion of a Mosquito Dunk® can be used. Homeowners, ranchers and
farmers looking for a safe, nontoxic way to control mosquitoes can use
Mosquito Dunks®, which kill mosquitoes before they can become flying,
biting, disease-carrying adults.