Bt israeliensis is highly effective against mosquito larvae and black fly larvae. Dunks can be used wherever mosquitoes breed: the periphery of ponds, lakes, flooded orchards, ditches, pastures, sewage or animal waste lagoons, roof gutters, run-off areas, and so on.
The dunks kill mosquitoes for 30 days or longer when placed in standing water outdoors. As the dunks dissolve, the Bti settles in the water where it is eaten by mosquito larvae. Dunks can be anchored with string to prevent them from being washed away. Alternate drying and wetting does not reduce their effectiveness. Use 1 dunk/100 sq. ft. of infested water.
Bti does not harm people, pets, birds, fish, or plants. Dunks also can be used as a preflood treatment in areas expected to become breeding sources.