Evaluation of criteria for species delimitation of bagworm moths (lepidoptera: Psychidae)

Abstract

Accurate identification of species is fundamental for biological research and necessary for species conservation. DNA barcoding is particularly useful when identification using morphological characteristics is laborious and/or unreliable. However, barcodes for species are dependent on the availability of reference sequences from correctly identified specimens. The traditional use of morphology to delimit the species boundaries of Finnish bagworm moths (Lepidoptera: Psychidae: Naryciinae: Dahliciini) is controversial because there is overlap in their morphological characteristics. In addition, there are no suitable molecular markers. We verified the delimitation of seven out of eight previously described taxa, by using the currently standardized COI barcode and phylogenetic inference based on fragments of mitochondrial (COI) and nuclear genes (MDH). Moreover, we compared the results of molecular methods with the outcome of geometric morphometrics. Based on molecular identification, our findings indicate that there are five sexual species (Dahlica and Siederia spp.) and two parthenogenetic species (D. fennicella and D. triquetrella) in Finland. We suggest that molecular methods, together with geometric morphometrics of male genitalia are an effective way of delimiting species of bagworm moths.