Bacillus thuringiensis for potato beetles (variety San Diego) was developed strain of the bacterium developed in 1986. It is designed exclusively for controlling the larvae of Colorado potato beetles and elm bark beetles. It does not kill the adult beetles.
Colorado potato beetles destroy leaves of potatoes, eggplant, tomatoes, and peppers. They are resistant to most conventional insecticides. However, Bt is effective against small larvae (less than 1/4 inch) and plants should be sprayed at egg hatch or when larvae are first seen.
Go to Yardener's Tool Shed for Bt Products or to Yardener's Helper for Controlling Colorado Potato Beetles.