Interspecific variation and sexual dimorphism of antennal receptor morphology, in European Yponomeuta (Latreille) (Lepidoptera : Yponomeutidae)

Abstract

Earlier studies have shown that reproductive isolation in European Yponomeuta is partly maintained by differences in sensitivity patterns of the antennal sensory equipment to sex attractants and plant volatiles. The objective of the current study is to elucidate whether these differences are reflected in antennal morphology. We therefore compared the sensory equipment on the 10th antennal segment of 9 European and 1 Japanese species of small ermine moths ( Yponomeuta spp.) (Lepidoptera : Yponomeutidae) and found that the same types of sensilla are present in both sexes of all species. Numbers of sensilla chaetica Types I and II, sensilla coeloconica and sensilla ttyloconica do not differ among the species and sexes. Numbers and distributions of sensilla trichodea and sensilla basiconica differ significantly among the species and the sexes. Five groupings of species can be discerned in both sexes, which largely correspond with one another. These groupings are not related to host plant preferences. The data are discussed in relation to possible functions of the differences found, and placed in context with a model on the taxonomy and evolution of the species.