The Role Of Mites In Bark And Ambrosia Beetle Fungal Interactions

Insects share complex interactions with mites and fungi that range from obligate mutualisms to antagonistic relationships. These multitrophic interactions often result in changes to the host environment and population dynamics of the insect. Here, we review Scolytidae and Platypodidae beetles (bark beetles and ambrosia beetles, Coleoptera: Curculionidae) and their micro-organismal interactions with mites and fungi. Many bark beetles and ambrosia beetles are closely associated with mutualistic fungi used as a food source. These fungi are carried by the beetles in specialized pockets called "mycangia." In addition to beetle-specific fungi, secondary fungi are often vectored by mite populations phoretic on the beetles. These secondary introductions create a complex fungal micro-biome within the host tree of the associated Scolytid beetles, with a myriad of consequences to beetle success and tree mortality. In this chapter, we provide a detailed review of specific beetle-fungal and mite-fungal associations, mutualistic and antagonistic effects of these fungal relations, and ecological and evolutionary consequences of beetle-fungal-mite relationships within the host complex.