Integrated data lead to correct identification: the case of yam insect pest, Digitivalva hemiglypha (Lepidoptera: Glyphipterigidae: Acrolepiinae)

Abstract

In this study, we corrected the misidentified insect pests on yam (Discorea polystachya), based on morphological characters and molecular analysis, and also firstly recorded the species in Korea. The species is a yam borer, Digitivalva hemiglypha Diakonoff & Arita. To accurate pest identification in future utility, genetic divergence within the genus Digitivalva including 43 individuals was calculated by adding samples from Korea and Japan. The intraspecific and interspecific genetic divergences in cytochrome oxidase subunit I, when calculated separately from D. hemiglypha I and D. hemiglypha II, had each constant average values along with other congeneric species: average 0.1% of intraspecific genetic divergence with ranges 0.0–0.7%; average 10.1% of interspecific genetic divergence with ranges 4.0–12.9%. Additionally, Automatic Barcode Gap Discovery results also recognized that two clades of D. hemiglypha were different molecular operational taxonomic units in the substitution models. Consequently, our results indicate that D. hemiglypha I is a correct D. hemiglypha in the cytochrome oxidase subunit I and it also supported by morphological comparison with the holotype of that. All sequences of D. hemiglypha I were nested in the same haplotype, with indicating the rapid dispersal. In further study, D. hemiglypha II will be re-checked as a distinct species of Digitivalva or other genus after examination of their specimens.

Keywords

• COI
• Genetic divergence
• Holotype
• Taxonomy
• Yam boring-insect