Bt for mosquitoes (for use in small areas).
These donut-shaped, floating briquettes release Bt (Bacillus thuringiensis var. israelensis) over a 30-day period.
Use 1 donut per 100 sq ft of water surface.
I have been buying Bt donuts for years. We have two small ponds and a dry-creek that will puddle here and there. When we first bought our property we were constantly getting swarmed by mosquitoes. There was a noticeable difference after we started to use the Bt with no ill effect to the frogs. They're alive and croaking. Well worth the investment!Review by AccomplishMoreToday (on 3/12/12)