XVI International Botanical Congess

The bark beetle species in the genus Dendroctonus (Coleoptera: Scolytidae) all feed on plants in the gymnosperm family Pinaceae, particularly on species within the genus Pinus. Previous work has shown that resource use in Dendroctonus is conservative, and related species tend to feed on plants of the same genus. Although host use is conservative at the genus-level in Dendroctonus, statistical tests uncovered no evidence for co-speciation between beetle species and host species over broad evolutionary time scales. Indeed, fossil and molecular evidence indicates that the Pinus hosts diversified much earlier than the beetles. However, recent work indicates that the distribution of host species has had a strong effect on speciation in Dendroctonus, particularly on more specialized beetle species. Although there was no broad pattern of co-speciation, I present evidence for particular co-speciation events between beetle populations on different Pinus subspecies.