New species of the genus Molanna Curtis, 1834 (Trichoptera, Molannidae) in China inferred from morphology and DNA barcodes

The male adult of Molannatruncata Ge, Peng & Sun sp. nov. is described and illustrated based on material collected in Si-chuan, China. It could be diagnosed by the subtriangular superior appendages when viewed dorsally, and by the mesal appendages each having a slender thorn and inferior appendages with a tiny inner process. Based on morphology of genitalia, we provide a dichotomous key to adult males of Molanna from the Oriental region. The DNA barcodes (partial mtCOI sequences) of M.truncatasp. nov. are generated and compared with existing sequences of Molanna species from Oriental and Palearctic regions. The mean intraspecific divergence of Molanna was 1.58% with a maximum of 8.50% in M.moesta. The Automatic Barcode Gap Discovery (ABGD) analysis of Molanna inferred 9 OTUs and thresholds of interspecific divergence of 10%. Divergence of M.truncatasp. nov. haplotypes from all other Molanna haplotypes ranged from 10.1% to 18%. We discuss distribution and potential groups of species within the Oriental Molanna species based on morphology.