curved-horn moths or gelechioid moths (Lepidoptera: Gelechioidea) represent one of the most diverse lepidopteran groups. Due to the large number of species, generally small size of adults and subtle morphological differences, their confident identification requires tenacious and long-term dedication on their diversity. over the past decade, DnA barcoding has repeatedly been used to elucidate boundaries of species in many large and difficult groups. Here, we conducted a test of DNA barcoding with the diverse fauna of Korean Gelechioidea with very little prior information of coi gene region from the area. Altogether 509 specimens representing 154 morphospecies were included in the study. the species assignments of all three tested species delimitation methods (ABGD, bptp and ptp) were consistent with morphological identifications for 117 species (75.97%). A threshold of 2.5% genetic divergence was observed to differentiate the morphological species efficiently. Careful morphological examination of morphospecies exceeding 2.5% intraspecific variability prove cryptic diversity in three species (Neoblastobasis biceratala, Evippe albidoesella and Promalactis atriplagata). one morphospecies, Promalactis odaiensis, showed high intraspecific divergence while consisted of only a single MotU. overall, DnA barcoding was shown to provide a powerful tool to discriminate species of Korean Gelechioidea and reveal cases of cryptic diversity. Curved-horn moths (Gelechioidea) is among the most species-rich superfamilies of the insect order Lepidoptera, containing 15-21 families 1-3. They are generally regarded as 'micro-moths' , and their life histories are greatly diverse as they occupy wide range of both terrestrial and aquatic habitats. The larvae may be external and internal feeders and larvae include concealers, case-bearers, twirlers, gall-makers and miners of vascular plants, mosses, lichens, seeds, dead plant materials and dung. Some species are scavengers or even predators 4. The superfamily has a worldwide distribution, comprising more than 18,000 described species 2. Typically, their adults have well-developed labial palps gently bent upward, giving an appearance of 'curved horn'. Species include many of agricultural, forestry and quarantine pests causing widespread damage around the world. The larvae of many species, such as Phthorimaea operculella (potato tuber moth), Scrobipalpa aptatella (tabacco stem borer) and Endrosis sarcitrella (white-shouldered house moth) cause serious damage to crops and stored grains by mining the leaves or burrowing into the seeds or fruits. Because of their usually tiny body size, indistinct appearance and cryptic behavior of adults, their identification to the species level is often difficult based on morphology. Over the past decade, DNA barcoding has developed to serve as an efficient troubleshooter in precise and fast identification of species, discoveries of cryptic species and surveys of biodiversity in a wide variety animal taxa and some other eukaryote groups 5-16. In particular, D...
