Search

Reproductive character displacement occurs when competition for successful breeding imposes a divergent selection on the interacting species, causing a divergence of reproductive traits. Here, we show that a disputed butterfly taxon is actually a case of male wing colour shift, apparently produced by reproductive character displacement. Using double digest restriction-site associated DNA sequencing and mitochondrial DNA sequencing we studied four butterfly taxa of the subgenus Cupido (Lepidoptera: Lycaenidae): Cupido minimus and the taxon carswelli, both characterized by brown males and females, plus C. lorquinii and C. osiris, both with blue males and brown females. Unexpectedly, taxa carswelli and C. lorquinii were close to indistinguishable based on our genomic and mitochondrial data, despite displaying strikingly different male coloration. In addition, we report and analysed a brown male within the C. lorquinii range, which demonstrates that the brown morph occurs at very low frequency in C. lorquinii. Such evidence strongly suggests that carswelli is conspecific with C. lorquinii and represents populations with a fixed male brown colour morph. Considering that these brown populations occur in sympatry with or very close to the blue C. osiris, and that the blue C. lorquinii populations never do, we propose that the taxon carswelli could have lost the blue colour due to reproductive character displacement with C. osiris. Since male colour is important for conspecific recognition during courtship, we hypothesize that the observed colour shift may eventually trigger incipient speciation between blue and brown populations. Male colour seems to be an evolutionarily labile character in the Polyommatinae, and the mechanism described here might be at work in the wide diversification of this subfamily of butterflies., European Regional Development Fund. Grant Numbers: CGL2016‐76322‐P, PID2019‐107078GB‐I00 Ministerio de Economía, Industria y Competitividad, Gobierno de España. Grant Number: BES‐2017‐080641 Ministerio de Ciencia, Innovación y Universidades Generalitat de Catalunya. Grant Number: 2017‐SGR‐991 Academy of Finland. Grant Number: 328895

Cryptic species represent a challenge for documenting global biodiversity. Even in well-studied groups, such as European butterflies, the application of integrative approaches has allowed the recognition of an unexpected number of cryptic taxa. Here, we combine the analysis of mitochondrial (cytochrome c oxidase I, COI) and nuclear (internal transcribed spacer 2, ITS2) markers with geometric morphometrics of the male genitalia to study diversity within the butterfly Muschampia proto. The nuclear marker reveals three well-supported and deeply diverged lineages, which are also detected based on mitochondrial DNA, although the latter recovers one of them as paraphyletic with poor support. These lineages also present distinct male genital characters, which allow blind assignment of > 97% of specimens when applying a jackknife procedure. We conclude that M. proto comprises three cryptic species that started to differentiate ~2 Mya: M. proto, distributed in northern Africa, the Iberian Peninsula and southern France; Muschampia alta comb. & stat. nov., occurring in southern Italy and the Balkan Peninsula; and Muschampia proteides, present in the easternmost part of Europe, the Near East and Iran. This discovery adds two new species to the European butterfly fauna and highlights the necessity to continue investigating potential cryptic diversity., We are grateful to all the colleagues who provided samples used in this study. Financial support for this research was provided by projects PID2019-107078GB-I00 / Agencia Estatal de Investigación / 10.13039/501100011033 and 2017-SGR-991 (Generalitat de Catalunya) to R.V., by a predoctoral fellowship BES-2017-080641 (Ministerio de Economía y Empresa de España) to J.C.H., by the Academy of Finland (decision no. 328895) to V.D. and by project RSF 19-14-00202 (from the Russian Science Foundation to the Zoological Institute of the Russian Academy of Sciences) to V.A.L., and by the project Servizio di attuazione delle azioni per la protezione degli impollinatori e diffusione dell’entomofauna del Parco Nazionale dell’Alta Murgia to L.D.

The Sympetrum vulgatum (Linnaeus, 1758) complex is composed of the subspecies S. vulgatum vulgatum, S. vulgatum decoloratum (Selys, 1884) and S. vulgatum ibericum Ocharan, 1985 in the West Palaearctic. These taxa have parapatric distributions and noticeable morphological differences in colour and body size, and their taxonomic status is debated. Here we revise the systematics of this group using molecular taxonomy, including molecular analyses of mitochondrial (cytochrome c oxidase subunit I, COI) and nuclear (internal transcribed spacer, ITS1) DNA taking into account known morphological differences. Each subspecies has a unique and differentiated COI haplotype, although divergences among them are low (0.4% maximum uncorrected p-distance). The subspecies are not differentiated by the nuclear marker ITS1. The genetic results for these taxa contrast with the deep divergence of the sister species S. striolatum (Charpentier, 1840). Given current evidence, we propose to maintain the subspecific status of the S. vulgatum complex and hypothesize their biogeographical history. It is likely that the three subspecies became isolated during one of the latest glacial periods, each in a different refugium: S. vulgatum ibericum possibly occupied the Iberian Peninsula, S. vulgatum vulgatum the Balkan Peninsula or territories further east and S. vulgatum decoloratum Anatolia.

Aim We describe fine-scale diversity patterns of the entire butterfly fauna occurring on the Tuscan Archipelago. By assessing the traits associated with population diversification, haplotype uniqueness and extinction, we aim to identify the factors determining the origin and maintenance of genetic diversity, and population vulnerability to environmental changes. Location Tuscan Archipelago, Sardinia, Tuscany (Italy) and Corsica (France). Methods We built a mtDNA dataset (1,303 COI sequences) for the 52 butterfly species reported in the Archipelago, also including specimens from neighbouring areas, and compiled data on 12 species traits and on the apparent extinction of species from the main islands. We calculated indices that measure genetic differentiation, and using phylogenetic regressions we evaluated the relationships between these indices and species traits. Finally, we inferred which traits are associated with disappearance of species on individual islands using phylogenetic regression. Results The overall spatial pattern of genetic diversity corresponded with the proximity of the areas, but strong contrasts were also identified between geographically close areas. Together with the island endemics, several common and widespread species had a high genetic diversification among islands and mainland. Phylogenetic regressions revealed that smaller-sized, more specialized species, with a preference for drier regions, displayed greater genetic structure and/or haplotype uniqueness. Species that disappeared from islands had a higher population diversification. Capraia has experienced a notable loss of diversity, which significantly affected species with shorter flight periods. Main conclusions Tuscan island butterflies are characterized by strong genetic contrasts and species differ in their contribution to the overall genetic diversity. By ranking the species for their contribution to genetic diversity and identifying the traits linked to the emergence and maintenance of diversity, we have developed a valuable tool for prioritizing populations as targets for monitoring and conservation action. The dataset constructed also represents a valuable resource for testing biogeographical hypotheses.