Phylogenetic relationships between the European and Asian eight spined larch bark beetle populations (Coleoptera, Scolyltidae) inferred from DNA sequences and fungal associates

The eight spined larch bark beetles infest various species of Lariw in Euro pe and Asia. Ips cembrae is the only Ips species with larch as its main hos t. Ips subelongatus, Ips fallax, Ips shinanonensis and Ips cembrae var, eng adinensis are treated as synonyms of I. cembrae. These three putative speci es and the one variety are distinguished by their host tree and geographic distribution, as it is not possible to distinguish them on the basis of mos phological differences. Beetles were collected from European and Asian popu lations, and from hosts and geographic areas where the species were first f ound and described and in their natural ranges of distribution. These beetl es were used to study the phylogenetic relationships of the eight spined la rch bark beetles. A region of the mitochondrial gene was analysed and the b lue-stain fungi associated with I. cembrae in Europe were investigated and compared with those recorded as associated with the larch bark beetle in Ja pan. Only minor sequence differences were detected between the populations in Europe and Asia. However, the European populations differed by 4.3% from the Asian populations. The phylogenetic analysis placed the European and A sian haplotypes in significantly distinct clusters. This distinction was su pported by the finding of an insertion/deletion in a non-coding region of t he mitochondrial DNA. Furthermore, there are differences in the fungi assoc iated with the eight spined larch bark beetles in Europe and Japan. The res ults suggest that the I. cembrae complex contains at least two taxa: I. cem brae infesting larch in Europe and I. subelongatus infesting larch in Asia.