Managing Insect Pests Using Microbial Biostimulants as Insecticides

Abstract

The plant–insect interactions are very complex and involve multiple factors. Herbivorous insects constitute 50% of the insects. Around 18%–26% global crop production losses are caused by pest insects. Modern agriculture is looking for effective biological tools to cope with these losses. The microbial biostimulants associated with plants can profoundly alter the plant–insect interactions. Microbe-induced changes enhance the plant defenses by changing the behavior and fitness of insect herbivores. Plants have developed strong symbiotic relationship with beneficial microbes, especially mycorrhizal fungi, plant growth-promoting rhizobacteria (PGPR) and other endophytes. Most of these beneficial microbes are living in the rhizosphere zone. Various endophytic fungi and bacteria are playing a vital role as microbial biostimulants to improve the plant health by suppressing the herbivory injuries through enhanced plant immune system. The microbe–plant interactions have the potential to stimulate the plant defenses directly as endophytes or indirectly by changing the insect physiology. Further research focusing on microbial biostimulants and their secondary metabolic compounds with effective insecticidal potential will surely lead to modernizations of biological control of insect pests.