Genetic split between coastal and continental populations of gypsy moth separated by Dinaric Alps

The gypsy moth, a polyphagous herbivore species, infests mainly deciduous trees in the northern hemisphere, being invasive in North America. In Croatia, gypsy moth is infesting both continental and coastal forests, with the Dinaric Alps posing a physical migratory barrier between two regions. During outbreaks, caterpillars cause severe damages in both regions, though with different outbreak dynamics, which suggests genetic differences between populations. Representative populations from these two regions were screened by sequencing a region of the mitochondrial COI gene. Ninety-nine sequences resulted in seventeen haplotypes, and analyses revealed a significant genetic differentiation between coastal and continental populations, quite likely attributed to geographic isolation and post-glacial history. This differentiation arises from significantly higher genetic variability in Mediterranean population, indicating their higher adaptability, an intriguing fact in case of possible northward range shift of gypsy moth.