Molecular phylogeny and evolutionary patterns of the european satyrids (Lepidoptera: Satyridae) as revealed by mitochondrial gene sequences

We examine the phylogenetic relationships of more than 40 species of European satyrids representing six tribes (Coenonymphini, Erebiini, Maniolini, Satyrini, Melanargiini, and Lethini). The analyses are based on comparisons of morphological data and mitochondrial genes encoding the large ribosomal subunit (16S rDNA) and NADH dehydrogenase subunit 1 (ND1). The cladistic reassessment of systematics based on morphological characters differs from the view retained by Miller by a lack in resolution due to the low number of characters used. Furthermore, some level of incongruence about the monophyly of the tribes is found between topologies from morphological and molecular analyses. In the case of Aphantopus hyperantus, molecular data and reexamination of morphology of this taxon indicate that this species has to be included within Maniolini. Contrary to the other clades, Erebia displays a radiate systematic pattern which cannot be explained by a lack of variable or informative sites. The combined spatial and temporal specialization found in the Erebia species may explain the rapid diversification of this genus relative to other satyrids. Finally, the subfamily level as defined by Miller for the taxa presented in the data set (Satyrinae and Elymninae) is not consistent with the molecular data. Given the reassessment of satyrids as a subfamily within Nymphalidae (Satyrinae), it seems more appropriate to retain the tribes as valid taxonomic ranks only in Satyrinae.     

Molecular phylogeny of swallowtail butterflies of the tribe Papilionini (Papilionidae, Lepidoptera).

Swallowtail butterflies of the tribe Papilionini number about 225 species and are currently used as model organisms in several research areas, including genetics, chemical ecology and phylogenetics of host plant utilization and mimicry, mechanisms of speciation, and conservation. We have inferred phylogenetic relationships for a sample of 18 species of the genus Papilio (sensu lato) and five outgroup taxa by sequencing two stretches of mitochondrial DNA that correspond to segments 12886-13370 and 12083-12545 of Drosophila melanogaster mitochondrial DNA and consist of sections of the genes for the large ribosomal RNA and subunit 1 of NADH-dehydrogenase. Our data support the monophyly of Papilio and, within it, of several traditionally recognized subgroups. Species belonging to groups that utilize primarily Rutaceae as larval foodplants form two clusters, corresponding to Old World and American taxa, respectively, while two previously recognized clades-of American and South Asian-Austronesian origin-whose members were known to feed mostly on Lauraceae and Magnoliaceae, are observed to form a clade. The sister group of Papilio is found to be the South Asian genus Meandrusa, which also happens to feed on Lauraceae. The latter plant family is therefore the probable larval host of the ancestor Papilio and the shift to Rutaceae (which four-fifths of extant Papilio species use as foodplants) is more likely to have occurred only after the initial diversification of the genus.     

Ecology and genetics of interspecific hybridization in the swallowtails, Papilio hospiton Gene and P. machaon L., in Corsica (Lepidoptera: Papiliomdae)

The Corsican swallowtail butterfly, Papilio hospiton , is endemic to Corsica and Sardinia (France and Italy) and included in the list of endangered species by the Washington Convention, It is spread all over Corsica in scattered populations linked to diverse habitats. A study by enzyme electrophoresis showed that the genetic diversity of the species is of the same order of magnitude as that of Papilio machaon from continental France and Corsica. The differentiation between populations is rather low, which is consistent with the high vagility of the adults. Natural hybridization between P. hospiton and P. machaon is frequent, and laboratory crosses show that the hybrids are not sterile. However, developmental perturbations impair the viability of further hybrid progenies. Although limited introgression between the two species is likely to take place, enzyme electrophoresis and PCR-RFLP analysis of mitochondrial DNA show that their gene pools remain distincfTtienetic assimilation by P. machaon therefore does not seem to be a threat for P. hospiton.     

Gene flow rise with habitat fragmentation in the bog fritillary butterfly (Lepidoptera: Nymphalidae)

Background  

The main components of the spatial genetic structure of the populations are neighbourhood size and isolation by distance. These may be inferred from the allele frequencies across a series of populations within a region. Here, the spatial population structure of Proclossiana eunomia was investigated in two mountainous areas of southern Europe (Asturias, Spain and Pyrenees, France) and in two areas of intermediate elevation (Morvan, France and Ardennes, Belgium).     

Hybridization and introgression between "full-fledged species". The case of Parnassius apollo and P. phoebus

Two butterfly species living in the Alps, Parnassius apollo and P. phoebus, frequently hybridize in certain localities of this region. The features of this phenomenon have been previously studied by biometry and starch gel electrophoresis, but some points remained obscure. We present them in a study combining results from cellulose acetate electrophoresis and wing pattern biometry with a determination of the mitochondrial haplotype by a PCR-RFLP analysis in a sample of butterflies from the southern French Alps. It was already known that the male hybrids are fecund and thus that interspecific gene exchange could take place via backcrosses with the parent species. In the present case, combining the identification of mtDNA with the analysis of nuclear genotypes allows us to demonstrate that hybridization can involve both sexes of both species. Moreover, it suggests that at least some female hybrids are not sterile. The impact of Haldane's rule is therefore not very strong in the present case. However, although the prerequisites for introgression between the concerned species are fulfilled, at the level of both nuclear and mitochondrial genomes, no indication of such a phenomenon could be gathered in the studied sample.