SPECIES STATUS AND POPULATION GENETIC-STRUCTURE OF THE FLIGHTLESS CHAFER BEETLES PRODONTRIA-MODESTA AND P-BICOLORATA (COLEOPTERA, SCARABAEIDAE) FROM SOUTH-ISLAND, NEW-ZEALAND

This study uses isozyme electrophoresis to investigate the systematic status of two rare flightless chafer beetle species, Prodontria modest a and P. bicolorata, currently distinguished solely on the basis of co lour. Seven polymorphic loci were analysed for the species in sympatry and allopatry. In sympatry, gene frequencies imply no genetic barrier between the two colour forms. Wright's hierarchical F-statistics were calculated to determine how the genetic variation is partitioned acro ss the geographic range of the two species. Strong geographic structur ing occurs at the population level but there is little genetic differe ntiation attributable to species. Comparisons of morphological measure ments are in support of the electrophoretic results. The systematic si gnificance of the two distinct colour forms is thus questionable. Unde r the biological, recognition or phylogenetic species concepts, the ge netic data suggest that there is only one species, polytypic for a col our pattern. Most of the genetic diversity of this group of beetles li es within and among populations, which differ quite markedly over thei r geographic range, rather than between the two named species.