Understanding insect-microbe interactions for sustainable pest management

Due to their enormous diversity, small body weight, flight and shorter lifecycles, insects thrive in almost all macro- and microhabitats. A plethora of microorganisms interact with insects as symbionts. Insect- microbial symbiont interaction can be either mutualistic, commensalism or pathogenic. The entry of a microbe mounts immune defenses in the insect at the local or systemic level in order to mitigate the damage inflicted. Microbes, on the other hand, synthesize various molecules/ toxins or develop various strategies to evade or counter insect defenses, allowing them to utilize the host resources for reproduction, coexistence or transmission. This review provides a comprehensive understanding of these insect-microbe interactions including bacteria, fungi and virus. Attempt has also been made to highlight the tripartite interactions between insects, microbes and plants in view of the need for sustainable pest management.