Phylogeography and bioclimatic models revealed a complicated genetic structure and future range shifts of Lymantria monacha L.

The phylogeography of economically important forest pests is important for understanding their demographic and evolutionary history. Linking the genetic data obtained with the bioclimatic models helps reveal future demographic trends of the pest species studied. Lymantria monacha is a polyphagous species that feeds on numerous coniferous and deciduous trees throughout the Palaearctic and is known to cause catastrophic defoliation, particularly in Europe. In addition, data from various mapping programmes over the last decade have revealed changes in the distribution of L. monacha. Therefore, in this study, we decided to clarify the evolutionary and demographic history of this important forest species using genetic data complemented by bioclimatic modelling. Our results confirmed the systematic status and monophyly of L. monacha. However, the lack of a geographical pattern between the studied regions suggests that the current genetic structure may be the result of recent dispersal events. Moreover, we found that the areas of high genetic diversity are consistent with potential past range shifts and survival of changes in climate and host plant availability. These two main variables also seem to determine the future range of L. monacha. Also, our modelling confirmed a poleward shift in its range and with a significant retraction from its current southern edge of distribution.