Higher level phylogeny of Satyrinae butterflies (Lepidoptera: Nymphalidae) based on DNA sequence data

We have inferred the first empirically supported hypothesis of relationships for the cosmopolitan butterfly subfamily Satyrinae. We used 3090 base pairs of DNA from the mitochondrial gene COI and the nuclear genes EF-1alpha and wingless for 165 Satyrinae taxa representing 4 tribes and 15 subtribes, and 26 outgroups, in order to test the monophyly of the subfamily and elucidate phylogenetic relationships of its major lineages. In a combined analysis, the three gene regions supported an almost fully resolved topology, which recovered Satyrinae as polyphyletic, and revealed that the current classification of suprageneric taxa within the subfamily is comprised almost completely of unnatural assemblages. The most noteworthy findings are that Manataria is closely related to Melanitini; Palaeonympha belongs to Euptychiina; Oressinoma, Orsotriaena and Coenonympha group with the Hypocystina; Miller's (1968). Parargina is polyphyletic and its components group with multiple distantly related lineages; and the subtribes Elymniina and Zetherina fall outside the Satyrinae. The three gene regions used in a combined analysis prove to be very effective in resolving relationships of Satyrinae at the subtribal and tribal levels. Further sampling of the taxa closely related to Satyrinae, as well as more extensive sampling of genera within the tribes and subtribes for this group will be critical to test the monophyly of the subfamily and establish a stronger basis for future biogeographical and evolutionary studies.     

Phylogenetics and biogeography of a spectacular Old World radiation of butterflies: the subtribe Mycalesina (Lepidoptera: Nymphalidae: Satyrini)

Background  

Butterflies of the subtribe Mycalesina (Nymphalidae: Satyrinae) are important model organisms in ecology and evolution. This group has radiated spectacularly in the Old World tropics and presents an exciting opportunity to better understand processes of invertebrate rapid radiations. However, the generic-level taxonomy of the subtribe has been in a constant state of flux, and relationships among genera are unknown. There are six currently recognized genera in the group. Mycalesis, Lohora and Nirvanopsis are found in the Oriental region, the first of which is the most speciose genus among mycalesines, and extends into the Australasian region. Hallelesis and Bicyclus are found in mainland Africa, while Heteropsis is primarily Madagascan, with a few species in Africa. We infer the phylogeny of the group with data from three genes (total of 3139 bp) and use these data to reconstruct events in the biogeographic history of the group.     

Population structure in relation to host-plant ecology and Wolbachia infestation in the comma butterfly

Experimental work on Polygonia c‐album, a temperate polyphagous butterfly species, has shown that Swedish, Belgian, Norwegian and Estonian females are generalists with respect to host‐plant preference, whereas females from UK and Spain are specialized on Urticaceae. Female preference is known to have a strong genetic component. We test whether the specialist and generalist populations form respective genetic clusters using data from mitochondrial sequences and 10 microsatellite loci. Results do not support this hypothesis, suggesting that the specialist and generalist traits have evolved more than once independently. Mitochondrial DNA variation suggests a rapid expansion scenario, with a single widespread haplotype occurring in high frequency, whereas microsatellite data indicate strong differentiation of the Moroccan population. Based on a comparison of polymorphism in the mitochondrial data and sequences from a nuclear gene, we show that the diversity in the former is significantly less than that expected under neutral evolution. Furthermore, we found that almost all butterfly samples were infected with a single strain of Wolbachia, a maternally inherited bacterium. We reason that indirect selection on the mitochondrial genome mediated by a recent sweep of Wolbachia infection has depleted variability in the mitochondrial sequences. We also surmise that P. c‐album could have expanded out of a single glacial refugium and colonized Morocco recently.     

Deflective and intimidating eyespots: a comparative study of eyespot size and position in Junonia butterflies

Eyespots are conspicuous circular features found on the wings of several lepidopteran insects. Two prominent hypotheses have been put forth explaining their function in an antipredatory role. The deflection hypothesis posits that eyespots enhance survival in direct physical encounters with predators by deflecting attacks away from vital parts of the body, whereas the intimidation hypothesis posits that eyespots are advantageous by scaring away a potential predator before an attack. In the light of these two hypotheses, we investigated the evolution of eyespot size and its interaction with position and number within a phylogenetic context in a group of butterflies belonging to the genus Junonia. We found that larger eyespots tend to be found individually, rather than in serial dispositions. Larger size and conspicuousness make intimidating eyespots more effective, and thus, we suggest that our results support an intimidation function in some species of Junonia with solitary eyespots. Our results also show that smaller eyespots in Junonia are located closer to the wing margin, thus supporting predictions of the deflection hypothesis. The interplay between size, position, and arrangement of eyespots in relation to antipredation and possibly sexual selection, promises to be an interesting field of research in the future. Similarly, further comparative work on the evolution of absolute eyespot size in natural populations of other butterfly groups is needed.     

Investigating Concordance among Genetic Data, Subspecies Circumscriptions and Hostplant Use in the Nymphalid Butterfly Polygonia faunus

Subspecies are commonly used taxonomic units to formally describe intraspecific geographic variation in morphological traits. However, the concept of subspecies is not clearly defined, and there is little agreement about what they represent in terms of evolutionary units, and whether they can be used as reliably useful units in conservation, evolutionary theory and taxonomy. We here investigate whether the morphologically well-characterized subspecies in the North American butterfly Polygonia faunus are supported by genetic data from mitochondrial sequences and eight microsatellite loci. We also investigate the phylogeographic structure of P. faunus and test whether similarities in host-plant use among populations are related to genetic similarity. Neither the nuclear nor the mitochondrial data corroborated subspecies groupings. We found three well defined genetic clusters corresponding to California, Arizona and (New Mexico+Colorado). There was little structuring among the remaining populations, probably due to gene flow across populations. We found no support for the hypothesis that similarities in host use are related to genetic proximity. The results indicate that the species underwent a recent rapid expansion, probably from two glacial refugia in western North America. The mitochondrial haplotype network indicates at least two independent expansion phases into eastern North America. Our results clearly demonstrate that subspecies in P. faunus do not conform to the structuring of genetic variation. More studies on insects and other invertebrates are needed to better understand the scope of this phenomenon. The results of this study will be crucial in designing further experiments to understand the evolution of hostplant utilization in this species.     

Phylogeography of the threatened butterfly, the woodland brown Lopinga achine (Nymphalidae: Satyrinae): implications for conservation

We have studied the phylogeography of the red-listed Palearctic butterfly Lopinga achine (Nymphalidae: Satyrinae) based on 1,450 base pairs of mitochondrial DNA sequences from 86 individuals representing 12 populations. Our results indicate a strong structuring of genetic variation, with among-population differences accounting for ca. 67% of the variation and almost all populations being significantly differentiated from each other. We surmise that the insular nature of populations as well as the low dispersal ability of the species has given rise to such a pattern. The genetic diversity within populations is low compared to that in other butterflies. Our results point to a scenario where the species originated in the Eastern Palearctic and expanded into Europe. Based on the analyses, we suggest that the Czech population merits the highest conservation priority. The two Swedish populations represent a distinct evolutionary lineage, and hence merit high conservation attention. The Estonian and Asian populations had the highest genetic diversity, and although we do not consider them to be under immediate threat, their genetic diversity should be conserved in the long term.     

Vagility: The Neglected Component in Historical Biogeography

The conceptual gap between ecological and historical biogeography is wide, although both disciplines are concerned with explaining how distributions have been shaped. A central aim of modern historical biogeography is to use a phylogenetic framework to reconstruct the geographic history of a group in terms of dispersals and vicariant events, and a number of analytical methods have been developed to do so. To date the most popular analytical methods in historical biogeography have been parsimony-based. Such methods can be classified into two groups based on the assumptions used. The first group assumes that vicariance between two areas creates common patterns of disjunct distributions across several taxa whereas dispersals and extinctions generate clade specific patterns. The second group of methods assumes that passive vicariance and within-area speciation have a higher probability of occurrence than active dispersal events and extinction. Typically, none of these methods takes into account the ecology of the taxa in question. I discuss why these methods can be potentially misleading if the ecology of the taxon is ignored. In particular, the vagility or dispersal ability of taxa plays a pivotal role in shaping the distributions and modes of speciation. I argue that the vagility of taxa should be explicitly incorporated in biogeographic analyses. Likelihood-based methods with models in which more realistic probabilities of dispersal and modes of speciation can be specified are arguably the way ahead. Although objective quantification will pose a challenge, the complete ignorance of this vital aspect, as has been done in many historical biogeographic analyses, can be dangerous. I use worked examples to show a simple way of utilizing such information, but better methods need to be developed to more effectively use ecological knowledge in historical biogeography.     

Infant Survival Among Free-Living Bonnet Macaques (Macaca radiata) in South India

International Journal of Primatology - Female reproductive success depends to a large extent on infants’ ability to survive to maturity. While most studies of female reproductive success have...     

Deceptive single‐locus taxonomy and phylogeography: Wolbachia‐associated divergence in mitochondrial DNA is not reflected in morphology and nuclear markers in a butterfly species

The satyrine butterfly Coenonympha tullia (Nymphalidae: Satyrinae) displays a deep split between two mitochondrial clades, one restricted to northern Alberta, Canada, and the other found throughout Alberta and across North America. We confirm this deep divide and test hypotheses explaining its phylogeographic structure. Neither genitalia morphology nor nuclear gene sequence supports cryptic species as an explanation, instead indicating differences between nuclear and mitochondrial genome histories. Sex‐biased dispersal is unlikely to cause such mito‐nuclear differences; however, selective sweeps by reproductive parasites could have led to this conflict. About half of the tested samples were infected by Wolbachia bacteria. Using multilocus strain typing for three Wolbachia genes, we show that the divergent mitochondrial clades are associated with two different Wolbachia strains, supporting the hypothesis that the mito‐nuclear differences resulted from selection on the mitochondrial genome due to selective sweeps by Wolbachia strains.