Biology and applications of endophytic insect-pathogenic fungi

Endophytic insect-pathogenic fungi (EIPF) are both plant mutualists and insect pathogens, living inside plant tissues without causing any symptoms to their plant partner while also parasitizing and killing insects [1].These interactions can occur simultaneously and lead to the demise of plant insect pests.The ecology and evolution of EIPF are still not fully understood; however, several studies have investigated their diversity [2,3], the mechanisms of plant and insect infection [4,5], and the nature of plant-insect-fungus relationships [6,7].These multikingdom interactions are of particular interest not only because EIPF are an ideal model for understanding the mechanisms of symbioses, but they are also widely used for practical applications and particularly relevant to agricultural pest control [8].Here, we provide an overview on EIPF by reviewing what is currently known about their evolution, ecology, and mechanisms of insect and plant colonization.We also address real-world applications of EIPF and identify possible research directions for the field in the future.