EUROPEAN AND NORTH-AMERICAN POPULATIONS OF GALERUCELLA-NYMPHAEAE (COLEOPTERA, CHRYSOMELIDAE) - 2 SEPARATE SPECIES REVEALED BY CHORION POLYPEPTIDE ANALYSIS

The Galerucella nymphaeae species complex is a controversial group of leaf-consuming beetles with a Holarctic distribution. It includes seve ral closely allied species or forms living in different habitats and u tilizing different food plants. In northern Europe, two species are en countered, G. nym phaeae (L.) living on Nuphar, and G. sagittariae (Gy llenhal) living on semiaquatic or terrestrial plants, while all North American forms have been so far considered conspecific with the Europe an G. nymphaeae. In the present study we have compared chorion polypep tides of the northern European G. nym phaeae and G. sagittariae with N orth American G. nymphaeae collected from Nuphar. The northern Europea n G. nymphaeae was found to differ from both northern European G. sagi ttariae and North American G. nymphaeae, which were found to be virtua lly identical in respect to their chorion polypeptides. The present re sults, coupled with earlier data concerning e.g. egg morphology, struc ture of larval cuticle, and comparison of several life history traits, demonstrate that northern European G. nymphaeae and North American G. nymphaeae are not conspecific, and that the North American G. nymphae ae may be more closely allied to the northern European G. sagittariae.