The pupal cremaster as a diagnostic character for species of Phyllonorycter (Lepidoptera : Gracillariidae), with description of a new species of the nipponicella complex from Japan

The pupal cremasters of twelve species of Japanese oak-feeding Phyllonoryct er are examined. The cremasters, even those of closely related species, are specifically distinct. Combined with descriptions of European and North Am erican species, the present results indicate that the cremaster can be used as a diagnostic character for the species of Phyllonorycter. A new species , P. persimilis, which was previously confused with P. similis Kumata, and the female of P. nipponicella (Issiki), hitherto unknown, are described. Th e nipponicella complex including these species is reviewed and the speciati on of its members is discussed in relation to diversification of the host p lant preference.