Summit Mosquito Dunks are available from purchase at King Feed and Hardware in Wimberley, Texas 78676.

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.

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.

  • Each dunk® kills mosquito larvae for 30 days or more.
  • Approved for use in organic production
  • Each dunk® covers up to 100 square feet of water, regardless of depth for 30 days or more
  • Use Mosquito Dunks® in any standing water including rain barrels, bird baths, tree holes, elevator shafts, planter reservoirs, rain gutters, etc

Mosquitoes lay their eggs directly in standing water or an area known to flood. While the adult mosquito is a typical six legged, four winged, flying insect pest, their larvae only survive in an aquatic environment. Mosquito Dunks® are a microbial larvicide, which means it controls only the larval stage of development utilizing a bacterial active ingredient. When placed in standing water the Dunks float and release a natural soil borne bacterium, Bti (Bacillus thuringiensis subspecies israeliensis). This bacteria is ingested by the mosquito larvae within the water and soon after kills the mosquito larvae with no effect on anything else. Mosquito Dunks® slow release properties mean that they keep releasing the Bti for at least 30 days or more, effectively keeping mosquitoes from emerging and becoming biting, disease spreading adults.

While Mosquito Dunks® will kill all mosquito larvae in standing water, they are labeled for use in animal watering troughs, ponds, birdbaths, and other areas in which animals and pets will drink and bathe. Mosquito Dunks® are also completely harmless to plants, fish, frogs, turtles and beneficial insects.

Mosquito Dunks® will remain effective for at least 30 days. When the Mosquito Dunk® has completely disappeared, it is time to replace.