Biological Control of Insect Pests for Sustainable Agriculture

Abstract

Maintenance of agricultural productivity is currently based mainly on extraneous application of fertilizers and pesticides. However, indiscriminate use of agrochemicals for controlling the pests and diseases led to pollution of soil, water, and food sources, poisoning of nontarget beneficial insects, and development of insect population resistant to insecticides. To obviate the pollution problem and obtain higher yields in a sustainable manner, biological control of insect pests using specific antagonistic microorganisms is an effective alternate approach with minimum deleterious effects. Microorganisms have been obtained from the rhizosphere of different crop plants that inhibited insect pests by producing toxins, bacteriocins, siderophores, hydrolytic enzymes, and other secondary metabolites. Moreover, plant hormones salicylic acid, jasmonic acid, and ethylene orchestrate a complex transcriptional programming that eventually leads to pest-induced SAR (systemic acquired resistance) and ISR (induced systemic resistance) in many plant species. Microbial genes involved in the biosynthesis of secondary metabolites and enzymes have been cloned and transferred to other microorganisms and plants to enhance the suppression and killing of insects. The efficiency of these biocontrol products can be further increased through genetic improvement, manipulation of the soil and plant environment, using mixtures of biocontrol agents, and optimization of formulations and by integration of biocontrol agents with other alternative methods that provide additive and synergistic effects. Thus, the application of effective biocontrol agents may reduce the use of chemical insecticides and support sustainable agriculture in an eco-friendly manner in tandem with improved crop productivity.