Molecular phylogeny of the Palaearctic butterfly genus Pseudophilotes (Lepidoptera: Lycaenidae) with focus on the Sardinian endemic P. barbagiae

Molecular Phylogeny and Taxonomy of the Butterfly Subtribe Scolitantidina with Special Focus on the Genera Pseudophilotes, Glaucopsyche and Iolana (Lepidoptera, Lycaenidae)

The Palearctic blue butterfly genus Pseudophilotes Beuret, 1958 is not homogenous regarding the morphology of its genital structures. For this reason, some of its species have been considered to be representatives of other genera of the subtribe Scolitantidina (subfamily Polyommatinae). Here, we address these taxonomic problems by analyzing the phylogenetic relationships between the genera, subgenera, and species of this subtribe inferred via the analysis of five nuclear and two mitochondrial DNA sequences. We demonstrate that the enigmatic Asian species P. panope (Eversmann, 1851) belongs to the genus Pseudophilotes but not to Praephilotes Forster, 1938 or Palaeophilotes Forster, 1938 and does not represent the independent genus Inderskia Korshunov, 2000, as hypothesized previously. We synonymize P. svetlana Yakovlev, 2003 (syn. nov.) and P. marina Zhdanko, 2004 (syn. nov.) with P. panope. We demonstrate a deep genetic divergence between lineages that were previously considered as subspecies of the single species Iolana iolas (Ochsenheimer, 1816). As a result, we confirm the multispecies concept of the genus Iolana Bethune-Baker, 1914. We show that the Holarctic genus Glaucopsyche can be divided into four subgenera: Glaucopsyche Scudder, 1872 (=Shijimiaeoides Beuret, 1958), Apelles Hemming, 1931, Bajluana Korshunov and Ivonin, 1990, and Phaedrotes Scudder, 1876.

Phylogeny, species delimitation and biogeography of the endemic Palaearctic tribe Tomarini (Lepidoptera: Lycaenidae)

The tribe Tomarini is represented by the sole genus Tomares, comprising about eight species distributed from the western Mediterranean to Central Asia. We carried out a multilocus phylogenetic and a biogeographical analysis to test the taxonomy of the genus by several molecular species delimitation methods and reveal patterns shaping the current distribution of Tomares. The phylogenetic analysis based on four molecular markers recovered the monophyly of the genus and recovered two deep-branching lineages: an African clade and an Asian clade. Species delimitation analyses suggested six or ten putative species depending on the method applied. The haplotype network analysis of the Tomares nogelii clade revealed no phylogeographical and taxonomic structure. We consider the taxon Tomares nesimachus (syn. nov.) a synonym of T. nogelii and reinstate Tomares callimachus dentata stat. rev. for populations from south-eastern Turkey. Tomares originated between the early Oligocene and the early Miocene, most probably in south-west Asia. The split of the most recent common ancestor of Tomares occurred between the middle-late Miocene and middle-late Pliocene, probably as a response to increasing aridification and habitat fragmentation. Differentiation of the Asian clade took place in south-west Asia during the Pliocene and Pleistocene and coincided temporally with the evolution of Tomares host plants of the genus Astragalus (Fabaceae).

Biogeography of Italy revisited: genetic lineages confirm major phylogeographic patterns and a pre-Pleistocene origin of its biota

Warm-adapted species survived the cold stages of the past glacial-interglacial cycles in southern European peninsulas and recolonized major parts of Central and Northern Europe in the wake of postglacial warming. However, many of the genetic lineages which differentiated within these refugia predate even the Pleistocene. One of these refugia is the Italian Peninsula with its surrounding islands. In this meta-analysis, we compiled phylogeographic patterns of multiple species across this region. We transformed existing geographic information on 78 animal and plant species (with a total of 471 genetic lineages) within 17 predefined areas into presence/absence matrices. We elaborated three matrices: (i) only old lineages exclusively distinguished by deep splits, (ii) only young lineages distinguished by shallow (i.e. recent) splits, and (iii) presence/absence of the respective species. To infer biogeographic relationships between the predefined areas, we performed bootstrapped neighbour joining cluster analyses on these three matrices. In addition, we reviewed the geological history of Italy to identify causes of the observed biogeographic patterns. We found Sardinia and Corsica to be biogeographically closely linked with each other, and that they diverge strongly from all other regions. Sicily also diverges strongly from all other regions, while the intra-island differentiation was comparatively low. On the Italian mainland, Calabria exhibited the most pronounced biogeographic differentiation, often with several lineages present, resulting from old vicariance events within the region. Furthermore, southern Apulia and the Po Plain with adjoining areas of northern peninsular Italy displayed considerable distinctiveness. Admixture prevailed in the areas between these three regions. The ancient isolation of Sicily, as well as Sardinia plus Corsica, resulted in endemic lineages with only moderate recent exchange with adjacent mainland regions. Pronounced diversification occurs within the Italian Peninsula. The complex tectonic activities, such as shifting (micro)plates, submergence of major parts of peninsular Italy with the genesis of numerous Pliocene islands, in combination with the climatic cycles during the Pleistocene have most likely generated the current biogeographic pattern of species. Immigrations from the Balkan Peninsula into northern Italy partly accounted for the distinctiveness of this region.

Wolbachia affects mitochondrial population structure in two systems of closely related Palaearctic blue butterflies

The bacterium Wolbachia infects many insect species and spreads by diverse vertical and horizontal means. As co-inherited organisms, these bacteria often cause problems in mitochondrial phylogeny inference. The phylogenetic relationships of many closely related Palaearctic blue butterflies (Lepidoptera: Lycaenidae: Polyommatinae) are ambiguous. We considered the patterns of Wolbachia infection and mitochondrial diversity in two systems: Aricia agestis/Aricia artaxerxes and the Pseudophilotes baton species complex. We sampled butterflies across their distribution ranges and sequenced one butterfly mitochondrial gene and two Wolbachia genes. Both butterfly systems had uninfected and infected populations, and harboured several Wolbachia strains. Wolbachia was highly prevalent in A. artaxerxes and the host's mitochondrial structure was shallow, in contrast to A. agestis. Similar bacterial alleles infected both Aricia species from nearby sites, pointing to a possible horizontal transfer. Mitochondrial history of the P. baton species complex mirrored its Wolbachia infection and not the taxonomical division. Pseudophilotes baton and P. vicrama formed a hybrid zone in Europe. Wolbachia could obscure mitochondrial history, but knowledge on the infection helps us to understand the observed patterns. Testing for Wolbachia should be routine in mitochondrial DNA studies.

Next generation sequencing-aided comprehensive geographic coverage sheds light on the status of rare and extinct populations of Aporia butterflies (Lepidoptera: Pieridae)

The Black-veined White Aporia crataegi (Linnaeus, 1758), a common and widespread butterfly ranging from northwestern Africa to Europe and Asia, has been extinct in Britain since the 1920s and is on a steady decline in several other parts of its range. In order to investigate genetic diversity within A. crataegi and its correspondence with current subspecies-level taxonomy, we barcoded 173 specimens from across its range including, for the first time, extinct populations from Britain and Korea. Using next generation sequencing we also obtained a sequence for Aporia joubini, a peculiar taxon from China known only by its type specimen collected in the early twentieth century. Our phylogenetic analysis placed A. joubini sister to A. oberthuri, although further taxon sampling may reveal a different scheme. Within A. crataegi, we observed a shallow and weak mitogenomic structure with only a few distinct lineages in North Africa, Sicily, Iran, and Japan. Eurasian populations, including those extinct in Britain and Korea, clustered into a large set of closely allied lineages, consistent with a recent expansion during the Late Pleistocene glacial period. This study highlights the importance of museum collections and the unique opportunities they provide in documenting species diversity and helping conservation efforts.