DNA-based identification of South Korean Megaloptera larvae with taxonomic notes

Mitochondrial DNA (mtDNA) sequences, which serve as DNA barcodes, have been used to associate immature and adult stages of insects and to delineate species. The partial mitochondrial cytochrome c oxidase subunit I (COI) gene sequences for South Korean Megaloptera (all known in the adult stage) were tested to identify undetermined larvae as a rapid and effective method from 31 specimens (16 adults and 15 larvae). The COI gene sequences distinguished all six known Megaloptera species, with a low genetic distance between larvae and adults (0.50±0.21%). Based on the COI gene sequences, we associated five types of larvae with known adults including the following four species of newly described larval stages: Sialis annae Vshivkova, 1979 (Megaloptera: Sialidae); Neochauliodes formosanus (Okamoto, 1910) (Megaloptera: Corydalidae); Parachauliodes asahinai Liu et al., 2008 (Megaloptera: Corydalidae); and Protohermes xanthodes Navás, 1913 (Megaloptera: Corydalidae). The known larval stage of Sialis koreana Jung and Bae, 2012 (Megaloptera: Sialidae) was confirmed, and the morphological variation in the male genitalia of Sialis longidens Klingstedt, 1932 (Megaloptera: Sialidae) is discussed. A larval key to the six South Korean species of Megaloptera is provided.