Large-scale phylogenetic structure of European springtails (Collembola) depends on species range size and postglacial colonization history

A new species of Entomobrya Rondani, 1861 (Collembola, Entomobryidae, Entomobryinae) from Croatia with the redescription of Entomobrya margaretae Gruia, 1967

In the present paper, a new species of the genus Entomobrya is described from Croatia. E. silvicola sp. nov. has a unique colour pattern that distinguishes it from other Entomobrya species in Europe and worldwide. Besides the different colour pattern, there are notable differences in the dorsal macrochaetotaxy and other characters that distinguish the new species from the other Entomobrya sharing the same dorsal macrochaetotaxy formula of Abd IIIII. Herein, we also provide the redescription of E. margaretae Gruia, 1967, based on topotypic specimens, of which a neotype was designated.

Mitogenomes of the two historical species Seiraferrarii Parona, 1888 and Seirapallidipes Reuter, 1895 (Collembola, Entomobryidae, Seirinae) with their phylogenetic placement within Seirinae

The present paper reports the first occurrence of Seiraferrarii Parona, 1888 from Hungary. On this occasion, molecular analyses were performed on both S.ferrarii and another historical species of the genus, S.pallidipes Reuter, 1895, originally described from Hungary. Using low-coverage whole-genome sequencing, the complete mitogenomes were assembled and annotated using MitoZ. To test the phylogenetic placement of both species, we performed maximum likelihood and Bayesian analyses using a matrix containing 14 Seirinae species and two outgroups. Both resultant trees showed that the European populations of the sampled Seira spp. likely derive from ancestral branches of Seirinae, compared to the Asian and American populations. Our results put in question the monophyly of the genus Seira, as already observed in previous studies.

Evidence for multiple colonisations and Wolbachia infections shaping the genetic structure of the widespread butterfly Polyommatus icarus in the British Isles

The paradigm of isolation in southern refugia during glacial periods followed by expansions during interglacials, producing limited genetic differentiation in northern areas, dominates European phylogeography. However, the existence of complex structured populations in formerly glaciated areas, and islands connected to mainland areas during glacial maxima, call for alternative explanations. We reconstructed the mtDNA phylogeography of the widespread Polyommatus Icarus butterfly with an emphasis on the formerly glaciated and connected British Isles. We found distinct geographical structuring of CO1 haplogroups, with an ancient lineage restricted to the marginal European areas, including Northern Scotland and Outer Hebrides. Population genomic analyses, using ddRADSeq genomic markers, also reveal substantial genetic structuring within Britain. However, there is negligble mito-nuclear concordance consistent with independent demographic histories of mitochondrial versus nuclear DNA. While mtDNA-Wolbachia associations in northern Britain could account for the geographic structuring of mtDNA across most of the British Isles, for nuclear DNA markers (derived from ddRADseq data) butterflies from France cluster between northern and southern British populations - an observation consistent with a scenario of multiple recolonisation. Taken together our results suggest that contemporary mtDNA structuring in the British Isles (and potentially elsewhere in Europe) largely results from Wolbachia infections, however, nuclear genomic structuring suggests a history of at least two distinct colonisations. This two-stage colonisation scenario has previously been put forth to explain genetic diversity and structuring in other British flora and fauna. Additionally, we also present preliminary evidence for potential Wolbachia-induced feminization in the Outer Hebrides.