ABSTRACT
The microbial control of pests refers to the exploitation of disease-causing organisms, viz., viruses, bacteria, fungi, protozoa and nematodes to reduce pest load below the economic threshold level (ETL). The performance of this group of biopesticides is influenced by environmental factors besides the virulence of strains. They are relatively slow, not compatible with chemical pesticides and have a short period of viability. Bacterial isolates belonging to Bacillus thuringiensis have been widely applied for control of bollworms, fruit borer, diamond back moth, Helicoverpa armigera in crops such as Cotton, Brinjal, Tomato, Okra, Cabbage, Cauliflower, Pulses. Similarly, entomophagous fungi predominantly belonging to Deuteromycetes such as Beauveria, Metarhizium, Nomuraea and Lecanicillium have been commercially exploited in insect control. Among the viruses, those belonging to Baculoviridae, have been effectively used for insect control. Nosema locustae is a moderately virulent protozoan that infects a wide range of grasshoppers and locusts. When mass production of microbial insecticides is perfected, they promise to be target-specific, eco-friendly options for insect control. Since microbial insecticides can be combined with several botanical pesticides, they form the most important pest management strategy in organic farming.
