André V. L. Freitas, Lucas Augusto Kaminski, Roger Vila, Gerard Talavera, National Science Foundation (US), Fundação de Amparo à Pesquisa do Estado de São Paulo, Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Brasil), European Commission, Generalitat de Catalunya, and Ministerio de Economía y Competitividad (España)
[Aim] Biogeographically puzzling taxa represent an opportunity to understand the processes that have shaped current species distributions. The systematic placement and biogeographical history of Elkalyce cogina, a small lycaenid butterfly endemic to Brazil and neighbouring Argentina, are long-standing puzzles. We use molecular tools and novel biogeographical and life history data to clarify the taxonomy and distribution of this butterfly., [Location] South America, with emphasis on the Atlantic Rain Forest and Cerrado biomes (Brazil and Argentina)., [Methods] We gathered a data set of 71 Polyommatini (Lycaenidae) samples, including representatives of all described subtribes and/or sections. Among these, we contributed new sequences for E. cogina and four additional relevant taxa in the target subtribes Everina, Lycaenopsina and Polyommatina. We inferred a molecular phylogeny based on three mitochondrial genes and four nuclear markers to assess the systematic position and time of divergence of E. cogina. Ancestral geographical ranges were estimated with the R package BioGeoBEARS. To investigate heterogeneity in clade diversification rates, we used Bayesian analysis of macroevolutionary mixtures (bamm)., [Results] Our results confirm the hypothesis that E. cogina belongs to the subtribe Everina and not Lycaenopsina, but unexpectedly recovered it as the sister group to the rest of Everina, with an estimated divergence time of approximately 10 Ma. Ancestral geographical range reconstruction points to an old colonization from Asia, the centre of diversity for the Everina, to the New World. The Neotropical Polyommatina lineage diversified to produce almost 100 species in multiple genera, whereas the E. cogina lineage did not diversify at all. Such lack of diversification is unique among the seven Everina/Polyommatina lineages that colonized the New World. We also show that the larvae of E. cogina feed on Fabaceae, supporting the identification of this host-plant family as the ancestral state for the whole group., [Main conclusions] The age and biogeographical reconstruction of the Elkalyce lineage are similar to those of the Neotropical lineage of Polyommatina and suggest that both travelled via the route proposed by Vladimir Nabokov (Asia-Beringia-North America-South America). This coincidence suggests that the climatic conditions at c. 10 Ma favoured dispersal from Asia to the Neotropics and that later events may have erased traces of these butterfly lineages in North America., Funding was provided by the Spanish Ministerio de Economía y Competitividad (project CGL2013-48277-P). G.T. is supported by the grant BP-A00275 (AGAUR-Generalitat de Catalunya), Marie Curie Actions FP7-PEOPLE-2013-IOF (project 622716) and the grant 1.50.1617.2013 at Saint Petersburg State University; L.A.K. was supported by CAPES (3200-14-0); A.V.L.F. thanks ICMBio for research permits (SISBIO no. 10802-5), CNPq (fellowship 302585/2011-7 and grant 564954/2010-1), RedeLep-SISBIOTA-Brasil/CNPq (563332/2010-7), the National Science Foundation (DEB-1256742), BR-BoL (MCT/CNPq/FNDCT 50/2010) and FAPESP (grant 2012/50260-6 and BIOTA-FAPESP Programs 2011/50225-3 and 2013/50297-0).