More than one application may be necessary for pest control. There are about 35 known strains of Bt. Each has a different range of insects it affects. Be sure to select the proper strain. For example, the Bt strain for caterpillars will not control beetles or vice versa.
Bt products come in spray, dust, granular, or pellet form.
They all contain living organisms, so it is important to follow storage directions given on the label. Protect from high temperatures. Use caution when applying Bt. Although Bt is considered virtually nontoxic to humans, susceptible individuals may develop serious allergic reactions if the bacterial spores are inhaled or rubbed into the skin. Therefore, avoid breathing spray mist or dust from various Bt products, and protect your eyes and skin when applying Bt.