Chemical Ecology of Bark Beetles in Regard to Search and Selection of Host Trees

Bark beetles (Coleoptera: Scolytidae), especially pests in the genera Dendroctonus, Ips, Scolytus, Trypodendron, Tomicus, and Pityogenes of the Northern hemisphere are reviewed regarding aspects of their chemical ecology during host finding and selection. Most of the species covered here feed on conifers, primarily pines (Pinus) in the Northern hemisphere and Norway spruce (Picea abies) of Europe and Asia. Bark beetles use a variety of olfactory strategies to discriminate suitable host trees from among less suitable, overcolonized, or decaying hosts as well as nonhosts. Bark beetles also use olfactory strategies to find mates and select attack sites. These strategies have implications for coevolution of trees and bark beetles. Knowledge of the chemical ecology of insect-insect and insect-plant relationships is necessary to develop improved methods for monitoring and controlling bark beetles that are predators of trees.