Evolutionary relationships within E uropean M onochamus ( C oleoptera: C erambycidae) highlight the role of altitude in species delineation

Phylogenetic relationships within the E uropean M onochamus ( C oleoptera: C erambycidae) remain understudied despite their increasing importance in the P ine W ood N ematode spread in E urope. To clarify the delimitation and the evolutionary history of the two main E uropean M onochamus species, M onochamus galloprovincialis and M onochamus sutor , as well as their sub‐species, a comparative study using morphological, molecular, and biogeographical criterions was conducted. Four morphological characters, including a newly‐described morphological character on the male genitalia, separated the two species. Additionally, molecular data revealed twelve and two single nucleotide polymorphisms in cytochrome oxidase c subunit I and 28 S , respectively, supporting species segregation. By contrast, incongruence between morphological and genetic results did not allow discriminating the sub‐species of M . galloprovincialis and M . sutor , even though mitochondrial DNA revealed intraspecific differentiation, mostly consenting to a multiple refugia origin. Within‐species variability was explained to a large extent by biogeography (i.e. altitude, climate). These different ecological adaptations within beetle species, together with potential climate change impact, increase the risk of spreading the nematode across E urope to novel conifer hosts and challenge the E uropean biosecurity. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society , 2013, 109 , 354–376.