DNA barcodes and citizen science provoke a diversity reappraisal for the "ring" butterflies of Peninsular Malaysia (Ypthima: Satyrinae: Nymphalidae: Lepidoptera).

The "rings" belonging to the genus Ypthima are amongst the most common butterflies in Peninsular Malaysia. However, the species can be difficult to tell apart, with keys relying on minor and often non-discrete ring characters found on the hindwing. Seven species have been reported from Peninsular Malaysia, but this is thought to be an underestimate of diversity. DNA barcodes of 165 individuals, and wing and genital morphology, were examined to reappraise species diversity of this genus in Peninsular Malaysia. DNA barcodes collected during citizen science projects-School Butterfly Project and Peninsular Malaysia Butterfly Count-recently conducted in Peninsular Malaysia were included. The new DNA barcodes formed six groups with different Barcode Index Numbers (BINs) representing four species reported in Peninsular Malaysia. When combined with public DNA barcodes from the Barcode Of Life Datasystems, several taxonomic issues arose. We consider the taxon Y. newboldi, formerly treated as a subspecies of Y. baldus, as a distinct species. DNA barcodes also supported an earlier suggestion that Y. nebulosa is a synonym under Y. horsfieldii humei. Two BINs of the genus Ypthima comprising DNA barcodes collected during citizen science projects did not correspond to any species previously reported in Peninsular Malaysia.