Bark beetle olfactory preferences in a changing world

Olfaction is the key to many multitrophic interactions involving insects, plants and microbes. In this project, we will investigate how climate change and atmospheric pollutants influence the chemical ecology and olfactory sense of insects with special emphasis on their relations with microbial symbionts and their host tree. Specifically, we will study the interactions between the bark beetle Ips typographus, its symbiotic ophiostomatoid fungi, and the conifer host tree (Picea abies). The Eurasian spruce bark beetle, Ips typographus is associated with a suite of ectosymbiotic ophiostomatoid fungi which aid beetles in colonization of trees and promotes development of offspring in the nutrient-limited phloem of the tree bark. The fungi associated with bark beetles vary geographically due to differences in temperature and other factors related to climate. We hypothesize that climate change is likely to affect the ecology and evolution of beetle-fungus interactions differently depending on the climatic zone. We will first investigate the variation in fungal communities from different I. typographus populations sampled across Europe. We will then test whether the preferences of beetles from different populations are correlated to geographic variation in fungal communities using electrophysiological and behavioral assays. Once we identify the existing variation, we aim to disentangle the molecular mechanisms behind the preference of native beetles to their native microbes by looking at potential nucleotide polymorphisms and expression level differences of bark beetle chemosensory genes specific to fungal odor detection.

Postdoctoral Researcher: Dr Dineshkumar Kandasamy (LU)

Supervision: Dr Martin N Andersson (LU), Dr Christer Löfstedt (LU), and Dr Bill S Hansson (MPI-CE).