Compatibility of Chemical and Biological Pesticides.

In the majority of crop systems today, emphasis is still placed on single technologies such as the use of pesticides, host plant resistance, and biocontrol, consideration rarely being given to their interaction (1). However, an important approach that could be taken in integrated pest management (IPM) programs is the use of biological pesticides together with a rational use of chemical pesticides. In fact, when a range of pests is present, or when only one method is not efficient, there may often be economic and environmental advantages in combining two or more control methods. Such methods need to be compatible with each other, as incompatibility can lead to loss in effectiveness, increased toxicity to humans and other nontarget organisms, the development of pesticide resistance, major product loss, and crop injury. Some information on the selectivity of most pesticides to natural enemies of pests is already known, but data on the compatibility of chemical and specific biopesticides are often limited and are sometimes conflicting (2).