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Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright Author's personal copy Molecular Phylogenetics and Evolution 61 (2011) 237–243 Contents lists available at ScienceDirect Molecular Phylogenetics and Evolution journal homepage: www.elsevier.com/locate/ympev Short Communication A phylogenetic revision of the Glaucopsyche section (Lepidoptera: Lycaenidae), with special focus on the Phengaris–Maculinea clade ⇑ L.V. Ugelvig a,c, , R. Vila b, N.E. Pierce c, D.R. Nash a a Centre for Social Evolution, University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark b Institut de Biologia Evolutiva (CSIC-UPF), Passeig Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain c Museum of Comparative Zoology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA article info abstract Article history: Despite much research on the socially parasitic large blue butterflies (genus Maculinea) in the past Received 29 January 2011 40 years, their relationship to their closest relatives, Phengaris, is controversial and the relationships Revised 20 April 2011 among the remaining genera in the Glaucopsyche section are largely unresolved. The evolutionary history Accepted 25 May 2011 of this butterfly section is particularly important to understand the evolution of life history diversity con- Available online 6 June 2011 nected to food-plant and host-ant associations in the larval stage. In the present study, we use a combi- nation of four nuclear and two mitochondrial genes to reconstruct the phylogeny of the Glaucopsyche Keywords: section, and in particular, to study the relationships among and within the Phengaris–Maculinea species. Ants We find a clear pattern between the clades recovered in the Glaucopsyche section phylogeny and their Lycaenid butterflies Parasitic caterpillars food-plant associations, with only the Phengaris–Maculinea clade utilising more than one plant family. Phylogeny Maculinea is, for the first time, recovered with strong support as a monophyletic group nested within Maximum likelihood Phengaris, with the closest relative being the rare genus Caerulea. The genus Glaucopsyche is polyphyletic, Bayesian inference including the genera Sinia and Iolana. Interestingly, we find evidence for additional potential cryptic spe- cies within the highly endangered Maculinea, which has long been suspected from morphological, ecolog- ical and molecular studies. Ó 2011 Elsevier Inc. All rights reserved. 1. Introduction Caterpillars overwinter in the ant nest, pupate there in the late spring and emerge as adult butterflies in the summer. Altogether, The European species of the large blue butterflies (genus they spend 11–23 months in the ant nest, imposing a considerable Maculinea van Eecke [1915], family Lycaenidae) have, considering fitness cost to the host-ant colony (for more details on Maculinea their rarity, been exceptionally well studied. This is primarily due biology and ecology see Thomas et al. (1989)). to their remarkable life cycle, which depends on the dual presence This specialized life cycle has attracted researchers from sev- of specific food-plants and host-ants. While these associations eral fields within biology, including evolutionary biologists, eager were described more than a century ago (Frohawk, 1906), only to understand its origin and evolution (Als et al., 2004; Fiedler, extensive research over the last 40 years has revealed their 1998; Fric et al., 2007; Pech et al., 2004; Pierce et al., 2002). extreme complexity (Barbero et al., 2009; Nash et al., 2008; Ant associations are common within the butterfly family Lycaeni- Thomas et al., 1989, 2009). dae, with 75% of the species with known life histories having Maculinea caterpillars initially live and feed on species-specific either obligate or facultative association with ants during part food-plants, however, when reaching the fourth instar, they under- of their development. The vast majority of these associations go a dramatic change in lifestyle. From being phytophagous, they are, however, mutualistic, where the attending ants protect the become obligately parasitic, only surviving if adopted into the caterpillars from natural enemies on the food-plant in return nests of certain ants of the genus Myrmica. In the ant nest, the cat- for nutritious secretions (Fiedler, 1991; Pierce et al., 2002). A par- erpillars live entirely as predators of ant grubs (larvae and pupae – asitic lifestyle involving both phytophagy and carnivory, such as the ‘‘predatory’’ lifestyle) or on a mixed diet of ant regurgitations, that found in Maculinea has evolved at least twice in the Lycaeni- unfertilized trophic eggs and ant grubs (the ‘‘cuckoo’’ lifestyle). dae (Pierce, 1995); in the Phengaris–Maculinea clade, and in the African genus Lepidochrysops.InLepidochrysops, the parasitic life- style appears to be associated with significant diversification ⇑ Corresponding author. Present address: Institute of Science and Technology (approximately 120 species; Fiedler, 1998; Pierce, 1995; Pierce Austria (IST Austria), Am Campus 1, A-3400 Klosterneuburg, Austria. Fax: +43 (0)2243 9000 2000. et al., 2002), a paradox since such life cycle complexity likely is E-mail address: [email protected] (L.V. Ugelvig). an evolutionary dead end (Pierce, 1995). Diversification is less 1055-7903/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.ympev.2011.05.016 Author's personal copy 238 L.V. Ugelvig et al. / Molecular Phylogenetics and Evolution 61 (2011) 237–243 pronounced in Phengaris–Maculinea, even if additional cryptic Samples previously used by Als and colleagues (2004) were species may exist in less intensively studied areas of their Palae- available from the DNA and Tissues collection of the Museum of arctic distribution ranges. Comparative Zoology (MCZ) at Harvard University, while new sam- Maculinea is placed in the Glaucopsyche section of the tribe ples were collected and stored in 96% ethanol at À20 °C prior to Polyommatini, together with the genera Glaucopsyche Scudder DNA extraction. Exceptions were Caerulea coligena (FH-05-M006) [1872], Scolitantides Hübner [1819], Pseudophilotes Beuret [1958], and Phengaris atroguttata (SY-02-J002), which had been dried be- Iolana Bethune-Baker [1914], Euphilotes Mattoni [1978], Philotes fore storage in 96% ethanol (see Tables S2 and S3 for a sample Scudder [1876], Philotiella Mattoni [1978], Palaeophilotes Forster overview). [1938], Praephilotes Forster [1938], Otnjukovia Zhdanko [1997], Turanana Bethune-Baker [1916], Sinia Forster [1940], Micropsyche 2.2. Molecular protocols Mattoni [1978], Subsolanoides Koiwaya [1989], Caerulea Forster [1938] and Phengaris Doherty [1891] (Als et al., 2004 and refer- DNA was extracted from single butterfly legs or one thoracic ences therein; Eliot, 1973; Mattoni, 1977, 1979). The relationships segment, using the InvisorbÒ Spin Tissue Mini Kit (Invitek GmbH, between these genera are poorly known, and were not well re- Westburg). Final elution volume was 60 lL and DNA aliquots were solved in a previous molecular phylogeny that included represen- stored at À20 °C. Two mitochondrial genes, cytochrome oxidase I tatives of ten of the genera (Als et al., 2004). Where life histories and II (COI and COII), and two nuclear genes elongation factor 1 al- are known, it is evident that each genus utilises food-plants from pha (EF1a) and wingless (wg) were amplified for all taxa. For the a single plant family and has facultative mutualistic associations taxa included in the general Glaucopsyche section phylogeny, two with their host-ants – with the exception of Maculinea and Pheng- additional, more slowly evolving nuclear genes were amplified, his- aris (Brower, 2008a; Fiedler, 1991, 1998; Pierce, 1995; Pierce et al., tone 3 (H3) and the ribosomal subunit 28S. Amplifications were 2002). Butterflies in the Oriental genus Phengaris, like Maculinea, carried out by standard polymerase chain reaction (PCR; see Sup- use food-plants from more than one plant family, and their cater- plementary material and Table S4 for PCR conditions and primer pillars have a parasitic lifestyle similar to that of Maculinea. Previ- information). Sequencing reactions were performed in a final reac- ous molecular and morphological studies point to Phengaris as the tion volume of 10 lL, using BigDye™ chemistry (Applied Biosys- closest genus to Maculinea (Als et al., 2004; Pech et al., 2004). How- tems), 10 lM primers and 10–20 ng DNA, and PCR products were ever, the two approaches do not agree on the relative position of precipitated using an MgCl2 protocol. Sequencing was conducted the two genera. While the molecular analysis recovered Maculinea in both directions on an Applied Biosystems 3031xl automated se- as a monophyletic group within Phengaris (Als et al., 2004), the quencer or by a sequencing facility (Macrogen). Retrieved se- morphological analysis placed Phengaris as a