Microbial Pesticides for Insect Pest Management: Success and Risk Analysis

Abstract

Biotic stress is a major cause for pre and postharvest losses in agriculture. Food crops of the world are damaged by more than of 10,000 species of insects 30,000 species of weeds, 1,00, 000 types of diseases (due to fungi, viruses, bacteria and various microbes) and a 1,000 species of nematodes. Modern day management practices for the above specified stress factors largely depends on the utilization of synthetic pesticides. Pesticide misuse in numerous sectors of agriculture frequently has often linked to health issues and environmental pollution around the world. Thus, there is a growing interest in replacing or possibly supplementing the prevailing control strategies with new and safer techniques. One of the promising management tools in this new state of affairs for crop protection is microbial pesticides. At present, only 3% of plant protectants used globally are covered by bio pesticides, but their growth rate indicates an increasing trend in the past two decades. The discovery of insecticidal property of Bacillus thuringiensis (Bt) indicated a more extensive part of organism based natural control. Microbial pesticides comprise of a microorganisms (bacterium, fungus, virus or protozoan) or toxins produced by them as the active ingredient. The most commonly used microbial pesticides are entomopathogenic fungi (Metarhizium, Beauveria and Verticillium), entomopathogenic bacteria (Bt), entomopathogenic nematode (Steinernema and Heterorhabditis) and baculoviruses (NPV and GV) which able to cause disease in insects. Microbial insecticides are promising alternative to ecologically disruptive pest control measures as they are no longer harmful to the environment and non target organisms. If deployed appropriately, microbial insecticides have capability to bring sustainability to global agriculture for food and food safety.