Genetic differentiation by geographic barrier has been considered to be primary factor for speciation of flightless carabid beetles. We studied genetic differentiation of three Leptocarabus (Coleoptera, Carabidae) species that inhabits different altitude to reveal the role of mountainous topography as geographic barrier. In Japanese Alps, L. arboreus, L. harmandi and L. procerulus are high-, middle-, and low-altitude species, respectively. The high- and middle- altitude species have seven and eight morphological subspecies. In this study we (1) compared between the species the level of genetic differentiation between mountain ranges, (2) examined how strength of geographic barrier (i.e. altitude of valleys between mountain ranges) affects within-species genetic differentiations and (3) tested whether subspecies were supported by molecular phylogeny.

Focal species were sampled in 2 sites of each of 8 mountain regions in entire Japanese Alps. DNA sequences of two or one individuals for each site for each species were obtained or have been being obtained for 2 mitochondrial (COI and ND5) and 4 nuclear (28S rDNA, Rho, PepCK and Wg) genes and possibly some other nuclear genes. We will present results of genetic differentiation and phylogeny based on those sequence data as well as their relation to geographical barrier and morphology.