Barcoding the butterflies of Argentina: species delimitation efficacy, cryptic diversity, and geographic patterns of divergence

GARCÍA, NATALIA C.; NUÑEZ BUSTOS, EZEQUIEL; HEBERT, PAUL D. N.; KOPUCHIAN, CECILIA; HEBERT, PAUL D. N.; KOPUCHIAN, CECILIA; TUBARO, PABLO L.; LIJTMAER, DARÍO A.; LAVINIA, PABLO D.; TUBARO, PABLO L.; LIJTMAER, DARÍO A.; LAVINIA, PABLO D.; GARCÍA, NATALIA C.; NUÑEZ BUSTOS, EZEQUIEL

Congreso; 7th International Barcode of Life Conference; 2017

Background: Lepidopterans constitute one of the most diverse groups of insects, with nearly 160 000 species worldwide. In Argentina, over 1200 species of butterflies have been described, with the highest diversity concentrated in the Atlantic Forest in Misiones province. We present here our most comprehensive analysis to date of the DNA barcodes of the Argentinian butterflies. Results: We analyzed 2161 specimens representing 429 species from 251 genera collected in eight provinces of northeastern and central Argentina. Mean intraspecific distance was 0.31%, being markedly lower than the mean interspecific distance (7.21%). More importantly, the average divergence to the nearest neighbour (6.91%) was 10 times larger than the mean distance to the farthest conspecific (0.69%). In fact, a barcode gap was observed for all species but four, which were the only ones found to be paraphyletic and (or) involved in cases of barcode sharing. Our barcode library allowed us to correctly identify species of butterflies in 96%?99% of the cases, depending on the identification criterion implemented. As of cryptic diversity, all species delimitation algorithms implemented (ABGD, TCS, RESL) delivered molecular operational taxonomic unit (MOTU) counts that were over the number of reference species with sequences (417), identifying 424?438 genetic clusters depending on the method. RESL (the algorithm used to delimit BINs on BOLD) delivered the highest percentage of MATCHES (93.5%) between species and MOTU boundaries. Finally, these analyses allowed us to identify several cases of both deep intraspecific splits (some of which are associated with geographic structure) and shallow to non-existentinterspecific divergence that will be studied in more depth. Significance: This study shows that DNA barcodes are extremely useful both for species identification of Argentinian butterflies and the discovery of cryptic diversity. At the same time, our project contributed to increased knowledge on lepidopterans and museum collections in Argentina and provided new species records for the country.