Host specificity in the Eurasian spruce bark beetle and the potential for host range expansion in a warming climate

The spruce bark beetles (Ips typographus) is a renowned pest of spruce (Picea spp.) trees in Eurasia. It has long been regarded as a specialist on spruce but recently it is increasingly attacking pine trees (Pine. spp.) as well. While this behavior is mostly apparent during hot and dry summers, when trees are stressed and beetle populations are large, it remains unknown why the beetles do this and how well they and their fungal symbionts perform on this secondary host. My project has two main objectives: (i) understanding the host preferences for pine vs spruce of the beetles, the underlying sensory biology and possibly genetics and (ii) understanding the potential fitness consequences for the beetles and their symbionts when they attack pine.