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

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

Congreso; 7th International Barcode of Life Conference; 2017

The African Centre for DNA Barcoding (ACDB) y University of Johannesburg (UJ)

Background: Lepidopterans constitute one of the most diversegroups of insects, with nearly 160 000 species worldwide. In Argentina,over 1200 species of butterflies have been described, with thehighest diversity concentrated in the Atlantic Forest in Misiones province. We present here our most comprehensive analysis to date of theDNA barcodes of the Argentinian butterflies. Results: We analyzed 2161 specimens representing 429 species from 251 genera collected ineight 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 divergenceto the nearest neighbour (6.91%) was 10 times larger than the mean distance to the farthest conspecific (0.69%). In fact, a barcode gap wasobserved 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 algorithmsimplemented (ABGD, TCS, RESL) delivered molecular operational taxonomicunit (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-existent interspecific 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 Argentinaand provided new species records for the country.