Juan L. Hernández-Roldán

DNA barcode reference library for Iberian butterflies enables a continental-scale preview of potential cryptic diversity

How common are cryptic species - those overlooked because of their morphological similarity? Despite its wide-ranging implications for biology and conservation, the answer remains open to debate. Butterflies constitute the best-studied invertebrates, playing a similar role as birds do in providing models for vertebrate biology. An accurate assessment of cryptic diversity in this emblematic group requires meticulous case-by-case assessments, but a preview to highlight cases of particular interest will help to direct future studies. We present a survey of mitochondrial genetic diversity for the butterfly fauna of the Iberian Peninsula with unprecedented resolution (3502 DNA barcodes for all 228 species), creating a reliable system for DNA-based identification and for the detection of overlooked diversity. After compiling available data for European butterflies (5782 sequences, 299 species), we applied the Generalized Mixed Yule-Coalescent model to explore potential cryptic diversity at a continental scale. The results indicate that 27.7% of these species include from two to four evolutionary significant units (ESUs), suggesting that cryptic biodiversity may be higher than expected for one of the best-studied invertebrate groups and regions. The ESUs represent important units for conservation, models for studies of evolutionary and speciation processes, and sentinels for future research to unveil hidden diversity.

Integrative analyses unveil speciation linked to host plant shift in Spialia butterflies.

Discovering cryptic species in well‐studied areas and taxonomic groups can have profound implications in understanding eco‐evolutionary processes and in nature conservation because such groups often involve research models and act as flagship taxa for nature management. In this study, we use an array of techniques to study the butterflies in the Spialia sertorius species group (Lepidoptera, Hesperiidae). The integration of genetic, chemical, cytogenetic, morphological, ecological and microbiological data indicates that the sertorius species complex includes at least five species that differentiated during the last three million years. As a result, we propose the restitution of the species status for two taxa often treated as subspecies, Spialia ali (Oberthür, 1881) stat. rest. and Spialia therapne (Rambur, 1832) stat. rest., and describe a new cryptic species Spialia rosae Hernández‐Roldán, Dapporto, Dincă, Vicente & Vila sp. nov. Spialia sertorius (Hoffmannsegg, 1804) and S. rosae are sympatric and synmorphic, but show constant differences in mitochondrial DNA, chemical profiles and ecology, suggesting that S. rosae represents a case of ecological speciation involving larval host plant and altitudinal shift, and apparently associated with Wolbachia infection. This study exemplifies how a multidisciplinary approach can reveal elusive cases of hidden diversity.

Morphological and chemical analysis of male scent organs in the butterfly genus Pyrgus (Lepidoptera: Hesperiidae)

Chemical communication in the family Hesperiidae (Lepidoptera) is practically unstudied, even though this group includes approximately 4,000 species and represents a fifth of the world’s butterfly fauna. We present the first comparative morphological and chemical analysis of scent organs for nine species in the genus Pyrgus, the most species-rich hesperiid genus in the Palearctic region. Our results show that the morphology of the two main male scent organs—the costal fold and the tibial tufts—does not differ between species. The chemical analyses detected a total of 125 different compounds exclusively present in these organs. We document great interspecific differences and much narrower intraspecific variability in the chemical profiles. The dynamics of chemical versus genetic distances indicate two different phases: a faster (but more variable) initial chemical divergence at lower genetic divergences (probably related to speciation) and a slower but more constant differentiation (drift). As a result most species can be identified based on their chemical profiles, except for a closely related species pair (P. malvae/P. malvoides) for which hybridisation is common in the contact zone. Our results suggest that the Hesperiidae is a group with great potential for the study of chemical communication that deserves further attention.

Multivariate analysis techniques in the study of the male genitalia of Pyrgus bellieri (Oberthür 1910) and P alveus (Hübner 1803) (Lepidoptera: Hesperiidae): species discrimination and distribution in the Iberian Peninsula

Abstract We used statistical multivariate analyses to study two morphologically similar species: Pyrgus bellieri and P. alveus. Ten different variables were measured in the male genitalia, and the results tested with Principal Component Analysis which showed a clear cut separation between the two species later confirmed by Discriminant Analysis. The discerning variables were the length of cuiller and the length of uncus that are inversely proportional in the two species. The classification functions for each species have been worked out resulting in the possibility to identify any individual just using some parameters in the male genitalia. The presence of P. bellieri in the Iberian Peninsula is confirmed and 18 literature citations of the species are rejected while 13 new ones are given. The resulting distribution in the Peninsula is restricted to 32 UTM squares (10 km) in the NE, all of them in Catalonia and in the Province of Huesca (Aragón). The study highlights the validity of statistical multivariate analysis techniques, using variables taken from the male genitalia, to discriminate species with identification problems.

Climatic niche evolution is faster in sympatric than allopatric lineages of the butterfly genus Pyrgus

Understanding how speciation relates to ecological divergence has long fascinated biologists. It is assumed that ecological divergence is essential to sympatric speciation, as a mechanism to avoid competition and eventually lead to reproductive isolation, while divergence in allopatry is not necessarily associated with niche differentiation. The impact of the spatial context of divergence on the evolutionary rates of abiotic dimensions of the ecological niche has rarely been explored for an entire clade. Here, we compare the magnitude of climatic niche shifts between sympatric versus allopatric divergence of lineages in butterflies. By combining next-generation sequencing, parametric biogeography and ecological niche analyses applied to a genus-wide phylogeny of Palaearctic Pyrgus butterflies, we compare evolutionary rates along eight climatic dimensions across sister lineages that diverged in large-scale sympatry versus allopatry. In order to examine the possible effects of the spatial scale at which sympatry is defined, we considered three sets of biogeographic assignments, ranging from narrow to broad definition. Our findings suggest higher rates of niche evolution along all climatic dimensions for sister lineages that diverge in sympatry, when using a narrow delineation of biogeographic areas. This result contrasts with significantly lower rates of climatic niche evolution found in cases of allopatric speciation, despite the biogeographic regions defined here being characterized by significantly different climates. Higher rates in allopatry are retrieved when biogeographic areas are too widely defined—in such a case allopatric events may be recorded as sympatric. Our results reveal the macro-evolutionary significance of abiotic niche differentiation involved in speciation processes within biogeographic regions, and illustrate the importance of the spatial scale chosen to define areas when applying parametric biogeographic analyses.

Corrigendum: DNA barcodes highlight unique research models in European butterflies

V. Dincă and P.D.N. Hebert. Biodiversity Institute of Ontario, University of Guelph, 50 Stone Road East, ON N1G 2W1, Canada. N. Backstrom. Department of Evolutionary Biology, Uppsala University, Norbyvagen 18D, 75236 Uppsala, Sweden. L. Dapporto. Department of Biological and Medical Sciences, Oxford Brookes University, Headington, Oxford, OX3 0BP, UK. M. Friberg. Department of Ecology and Genetics, Plant Ecology and Evolution, Uppsala University, Norbyvagen 18D, 75236 Uppsala, Sweden. E. Garcia-Barros, J. Hernandez-Roldan, and M.L. Munguira. Department of Biology, Universidad Autonoma de Madrid, Campus Cantoblanco 28049, Madrid, Spain. E. Hornett. Department of Zoology, University of Cambridge, Cambridge, CB2 3EJ, UK. V. Lukhtanov. Department of Karyosystematics, Zoological Institute of Russian Academy of Sciences, Universitetskaya nab. 1, 199034 St. Petersburg, Russia. F. Marec and J. Sichova Faculty of Science, University of South Bohemia, Ceske Budějovice, 370 05, Czech Republic. S. Montagud. Institut Cavanilles de Biodiversitat i Biologia Evolutiva (ICBiBE) Universitat de Valencia, Carrer Catedratic Jose Beltran 2, 46980, Paterna, Spain. M. Olofsson and C. Wiklund. Department of Zoology, Stockholm University, Svante Arrhenius vag 18B, S-106 91, Stockholm, Sweden. G. Talavera. Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University, 26 Oxford St., 02138 Cambridge, MA, USA. J.C. Vicente-Arranz. Asociacion Espanola para la Proteccion de las Mariposas y su Medio (Zerynthia), Logrono (La Rioja), Spain. R. Vila. Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra), Passeig Maritim de la Barceloneta 37, 08003, Barcelona, Spain. Corresponding author: Vlad Dincă (e-mail: vdinca@uoguelph.ca). 391