Discrimination of Torymus sinensis Kamijo (Hymenoptera: Torymidae) and T. beneficus Yasumatsu et Kamijo and their hybrids by allele-specific PCR

Abstract

Torymus sinensis and Torymus beneficus (Hymenoptera: Torymidae) are, respectively, introduced and indigenous parasitoid wasps that attack the invasive chestnut gall wasp, Dryocosmus kuriphilus (Hymenoptera: Cynipidae) in Japan. Torymus beneficus has two emergence types in spring, here designated early-spring and late-spring. It is very difficult to distinguish these Torymus species and emergence types of T. beneficus by their morphological and ecological characteristics. We designed four allele-specific primers for the internal transcribed spacer 1 region of nuclear ribosomal DNA, and developed three kinds of allele-specific PCR. These methods enabled us to distinguish the species, emergence type, and F1s. This is the first report of the use of molecular markers to distinguish T. sinensis, the late-spring strain of T. beneficus, and their F1s.