Genetic diversity of aboriginal and invasive populations of four‐eyed fir bark beetle P olygraphus proximus B landford ( C oleoptera, C urculionidae, S colytinae)

The four‐eyed fir bark beetle P olygraphus proximus B landf., native in F ar E astern E urasia and nearby islands, is an invasive pest of fir trees in S iberian and E uropean parts of R ussia. Its invasion has been overlooked and was only finally appreciated in 2008. Subsequently, the scale and area of damage to the forests has increased catastrophically. Thus, extensive monitoring and population control are required to localize and stop any further spread of the invasion. We used mitochondrial DNA markers to analyze the genetic diversity and population structure of invasive and aboriginal populations of P . proximus , aiming to establish the main sources and corridors of its spread and to infer the history of colonization. Eighteen haplotypes clustered in five groups were identified. The aboriginal populations had the highest degree of haplotype variability, including almost all haplotypes found in the areas of invasion. The S iberian introduced populations had a sufficient reduction of genetic variation, and a strong geographical partitioning. The E uropean populations mostly had the same haplotypes as the invasive S iberian populations. The results of the present study support the scenario of P . proximus spreading from the F ar E ast of R ussia westward via timber transport along the major R ussian railway network.