Intraspecific variation in sexual isolation in the jewel wasp Nasonia

Divergence in mate recognition systems can lead to reproductive isolation. In this study, we investigate patterns of intraspecific variation that cont ribute to premating isolation within and between two haplodiploid species, Nasonia vitripennis and N. longicornis. In a broad-scale survey of 17 North American isofemale lines encompassing the two species, we report strong as ymmetric sexual isolation between species and a dramatic level of intraspec ific variation for mate discrimination between species. A general lack of i ncipient speciation was found, with the exception of low levels of interpop ulational sexual isolation within N. vitripennis. Regression analysis shows that the degree of intraspecific variation for within-species mating frequ ency is not associated with the degree for between-species mating frequency . Reinforcement or reproductive character displacement may be involved in s ome of the variation in interspecies premating isolation.