Non-destructive DNA extraction method for identification of Bradysia odoriphaga (Diptera: Sciaridae), a pest of Welsh onion, carrot, and Chinese chive in Japan

We examined the utility of a non-destructive DNA extraction method for identification of Bradysia odoriphaga Yang and Zhang, 1985 (Diptera: Sciaridae) based on PCR using species-specific primers and DNA barcoding targeting the mitochondrial cytochrome c oxidase subunit I gene. Using species-specific primers, PCR success rates for adults and pupae were more than 90%, while those for larvae and eggs were 51% and 13%, respectively. The success rates of PCR for DNA barcode region were slightly higher than those of PCR using species-specific primers. In all sequenced samples, the 658 bp of sequences in the DNA barcode region were identical to the sequences from B . odoriphaga that we previously obtained using a destructive DNA extraction method. The adults were successfully identified based on morphological characters after non-destructive DNA extraction. The non-destructive DNA extraction method examined in this study is useful for the identification of adults and pupae of B . odoriphaga collected in the fields.