Origin of non-native Xylosandrus germanus, an invasive pest ambrosia beetle in Europe and North America

Authors: DZURENKO, MAREK - Technical University In Zvolen; Ranger, Christopher; HULCR, JIRI - University Of Florida; GALKO, JURAJ - National Forest Centre; KANUCH, PETER - Slovak Academy Of Sciences

Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2020
Publication Date: 9/25/2020
Citation: Dzurenko, M., Ranger, C.M., Hulcr, J., Galko, J., Kanuch, P. 2020. Origin of non-native Xylosandrus germanus, an invasive pest ambrosia beetle in Europe and North America. Journal of Pest Science. 94(2):553-562. https://doi.org/10.1007/s10340-020-01283-x.
DOI: https://doi.org/10.1007/s10340-020-01283-x

Interpretive Summary: Exotic ambrosia beetles (Coleoptera: Scolytinae: Xyleborini) are among the most important and destructive pests in forests, tree nurseries and plantations worldwide. Their cryptic lifestyle, fungal mutualism, inbreeding, and broad host range have predisposed them to become remarkably successful invaders and colonize novel habitats across the world. The black timber bark beetle, Xylosandrus germanus (Blandford), is native to East Asia, but now established in North America and Europe. It is an economically significant invasive pest in North American nurseries and orchards, and European forests. Managing and preventing the spread of exotic species such as X. germanus requires an understanding of invasion pathways and mechanisms associated with their source populations. In this study, we sequenced mitochondrial and nuclear genes from a large sample of X. germanus specimens from native and non-native habitats to identify source populations in invaded areas. The genetic structure of X. germanus in non-native habitats is highly uniform and points to independent introductions to N. America and Europe from mainland Japan. European populations were probably introduced only once prior to 1951, but our current study supports multiple independent introductions since then. These results will be useful to understand mechanisms of human-assisted transport of exotic ambrosia beetles.

Technical Abstract: Xyleborine ambrosia beetles (Coleoptera: Scolytinae: Xyleborini) are among the most important and destructive pests in forests, tree nurseries and plantations worldwide. Their cryptic lifestyle, fungal mutualism, inbreeding, and broad host range have predisposed them to become remarkably successful invaders and colonize novel habitats across the world. The black timber bark beetle, Xylosandrus germanus (Blandford), is native to East Asia, but now established in North America and Europe. It is an economically significant invasive pest in North American nurseries and orchards, and European forests. Managing and preventing the spread of exotic species such as X. germanus requires an understanding of invasion pathways and mechanisms associated with their source populations. In this study, we sequenced the mitochondrial gene COI and nuclear gene ArgK from an extensive sample (98 individuals) of native and non-native X. germanus to identify source populations in invaded areas. The genetic structure of X. germanus in non-native habitats is highly uniform and points to independent introductions to N. America and Europe from mainland Japan. While European populations were probably introduced only once prior to 1951, the nuclear genetic pattern of North American populations suggests X. germanus was introduced several times independently.