DNA barcodes as a tool for fast biodiversity census and establishment of taxonomic workflows: the case of the mostly unknown moths of Argentina

LAVINIA, PABLO D.; NÚÑEZ BUSTOS, EZEQUIEL; KOPUCHIÁN, CECILIA; LIJTMAER, DARÍO; HEBERT, PAUL D. N.; TUBARO, PABLO

Congreso; 7th International Barcode of Life Conference; 2017

Background: Lepidopterans constitute one of the most diverse groups of insects with a total estimated diversity of nearly half a million species. Most of this diversity is yet to be describedand corresponds to species of moths, which represent around 80% of all known species of lepidopterans. In Argentina, there is no ocial count of moth species and taxonomic knowledgeof this group is scarce. We used DNA barcodes to explore moth diversity in the southernmost region of the Atlantic Forest, a biodiversity hotspot. Results: We sampled 1,655 specimensrepresenting 622 taxa (Linnaean species or morphospecies determined by us based on external morphology) from 27 families of moths collected in Misiones province. Nearly half of the taxa(305) corresponded to morphospecies as we were not able to identify the specimens to the species level. All the clustering algorithms implemented (ABGD, TCS, RESL) evidenced theexistence of cryptic diversity, with MOTU counts (632-655) always exceeding the number of reference taxa (611). More precisely, we found a great correspondence (97%) between alreadydescribed Linnaean species and MOTU boundaries, but not between MOTUs and morphospecies (86%). This was because the algorithms merged and split many more morphospecies thanLinnaean species. This appears to be a consequence of incorrect morphospecies assignment due to unknown intraspecic polymorphism and sexual dimorphism, and the existence ofcryptic species. Significance: This study shows that DNA barcodes performed better than the morphospecies approach when dealing with unknown entities. Furthermore, this tool can beused to rapidly delimit putative species that could serve as the foundation for subsequent, more detailed taxonomic studies. At the same time, DNA barcodes are useful for acceleratingbiodiversity census and uncovering of cryptic diversity, even in poorly known groups, like the moths of Argentina.