Microbial control often involves the application of the microbe as a biological pesticide or biopesticide. No, research on beneficial microorganisms has been going on for decades. The vast majority of microbes causing diseases in invertebrates are safe to vertebrates, and we know well how to separate any that could cause ill effects. Microbes for control of weeds must be tested especially rigorously to ensure that they cannot harm crop plants. Biopesticides must be registered before commercial use, and the registration process provides a check of their safety.
Many microbes are already registered and being used as safe and effective commercial products.
Indeed, one of the main reasons for developing these products is that they offer safer pest control than chemical pesticides. Microbial control can provide new options for tackling long-standing pest problems. Many species become pests when they are introduced from one region to another without the natural enemies that previously kept them in check. However, in other cases, classical biological control agents take time to establish, or are in some ways limited in their effectiveness. Microbial control can provide a stop-gap while the classical biocontrol agent takes hold, or can supplement the action of classical biological control where introduced natural enemies are not fully effective in the new situation.