How Hosts Taxonomy, Trophy, and Endosymbionts Shape Microbiome Diversity in Beetles.

Bacterial communities play a crucial role in the biology, ecology, and evolution of multicellular organisms. In this research, the microbiome of 24 selected beetle species representing five families (Carabidae, Staphylinidae, Curculionidae, Chrysomelidae, Scarabaeidae) and three trophic guilds (carnivorous, herbivorous, detrivorous) was examined using 16S rDNA sequencing on the Illumina platform. The aim of the study was to compare diversity within and among species on various levels of organization, including evaluation of the impact of endosymbiotic bacteria. Collected data showed that beetles possess various bacterial communities and that microbiota of individuals of particular species hosts are intermixed. The most diverse microbiota were found in Carabidae and Scarabaeidae; the least diverse, in Staphylinidae. On higher organization levels, the diversity of bacteria was more dissimilar between families, while the most distinct with respect to their microbiomes were trophic guilds. Moreover, eight taxa of endosymbiotic bacteria were detected including common genera such as Wolbachia, Rickettsia, and Spiroplasma, as well as the rarely detected Cardinium, Arsenophonus, Buchnera, Sulcia, Regiella, and Serratia. There were no correlations among the abundance of the most common Wolbachia and Rickettsia; a finding that does not support the hypothesis that these bacteria occur interchangeably. The abundance of endosymbionts only weakly and negatively correlates with diversity of the whole microbiome in beetles. Overall, microbiome diversity was found to be more dependent on host phylogeny than on the abundance of endosymbionts. This is the first study in which bacteria diversity is compared between numerous species of beetles in a standardized manner.

Reconstructed historical distribution and phylogeography unravels non-steppic origin of Caucasotachea vindobonensis (Gastropoda: Helicidae).

Existing data on the phylogeography of European taxa of steppic provenance suggests that species were widely distributed during glacial periods but underwent range contraction and fragmentation during interglacials into "warm-stage refugia." Among the steppe-related invertebrates that have been examined, the majority has been insects, but data on the phylogeography of snails is wholly missing. To begin to fill this gap, phylogeographic and niche modeling studies on the presumed steppic snail Caucasotachea vindobonensis were conducted. Surprisingly, reconstruction of ancestral areas suggests that extant C. vindobonensis probably originated in the Balkans and survived there during the Late Pleistocene glaciations, with a more recent colonization of the Carpatho-Pannonian and the Ponto-Caspian regions. In the Holocene, C. vindobonensis colonized between the Sudetes and the Carpathians to the north, where its recent and current distribution may have been facilitated by anthropogenic translocations. Together, these data suggest a possible non-steppic origin of C. vindobonensis. Further investigation may reveal the extent to which the steppic snail assemblages consist partly of Holocene newcomers.

Enzymatic Activity of Soil on the Occurrence of the Endangered Beetle Cheilotoma musciformis (Coleoptera: Chrysomelidae) in Xerothermic Grasslands.

This work attempts to find the reasons for the rather limited range of occurrence of Cheilotoma musciformis in Poland, based on soil properties, which affects both the plant cover and the entomofauna. The aim of the study was to assess the influence of soil enzyme activity on the occurrence of Ch. musciformis in xerothermic grasslands in Southern Poland. The sites inhabited by the beetle were most often extensively grazed by farm animals or had recently been cleared of bushes. The control plots were in wasteland. The soils of most sites with Ch. musciformis were characterized by significantly higher activity of the tested enzymes and higher content of total organic carbon and total nitrogen, as well as lower pHKCl compared to the control sites. The higher enzymatic activity of soils in sites with the beetle than in the control sites may indicate the dependence of the occurrence of this beetle on the presence of patches of extensively grazed xerothermic grasslands. Grazing influences the behavior of preferred host plant species. Therefore, when planning active protection of xerothermic grasslands inhabited by Ch. musciformis, changes in the biochemical properties of the soil and vegetation structure should be taken into account.

Limited congruence in phylogeographic patterns observed for riverine predacious beetles sharing distribution along the mountain rivers.

Riverine predacious beetles (RPB) (Carabidae, Staphylinidae) are highly diverse and numerous elements of riverine ecosystems. Their historical and contemporary distribution and diversity are highly dependent on natural flow regimes and topography of watercourses. Despite broad knowledge of their ecology, data on population genetic diversity and connectivity are lacking. This study aimed to fill this gap in order to solve two principal hypotheses assuming (i) congruence of phylogeographic patterns observed for RPB indicating that they share a common history and the ecological adaptations to the dynamic environment, (ii) genetic structuration of populations according to river basins. The Carpathian populations of four ground beetles and three rove beetles were examined using cytochrome oxidase and arginine kinase sequencing. There are substantial differences in RPB demographic history and current genetic diversity. Star-like phylogeny of Bembidion and complex haplotype networks of Paederus/Paederidus, with some haplotypes being drainage-specific and others found in distant populations, indicate a general lack of isolation by distance. Signs of recent demographic expansion were detected for most RPB with the latest population collapse for some rove beetles. To some extent, migration of examined species has to be limited by watersheds. Observed phylogeographic patterns are essential for correctly understanding RPB meta-population functioning.

Using host species traits to understand the Wolbachia infection distribution across terrestrial beetles.

Knowledge of Wolbachia prevalence with respect to its hosts is restricted mainly to taxonomic/phylogenetic context. In contrast, relations between infection and most host's ecological and biological traits are poorly understood. This study aimed to elaborate on relations between bacteria and its beetle hosts in taxonomic and the ecological contexts. In particular, the goal is to verify which ecological and biological traits of beetles could cause them to be prone to be infected. Verification of Wolbachia infection status across 297 beetle taxa showed that approximately 27% of taxa are infected by supergroups A and B. Only minor support for coevolution between bacteria and its beetle hosts was observed in some genera of beetles, but in general coevolution between beetles and Wolbachia was rejected. Some traits of beetles were found to be unrelated to Wolbachia prevalence (type of range and thermal preferences); some traits were related with ambiguous effects (habitats, distribution, mobility and body size); some were substantially related (reproduction mode and trophy). The aforementioned summary does not show obvious patterns of Wolbachia prevalence and diversity in relation to host taxonomy, biology, and ecology. As both Wolbachia and Coleoptera are diverse groups, this lack of clear patterns is probably a reflection of nature, which is characterised by highly diversified and probably unstable relations.

The morphology of the preimaginal stages of Rhinusaneta (Germar, 1821) and notes on its biology (Coleoptera, Curculionidae, Mecinini).

A detailed description of the mature larva and pupa of Rhinusaneta (Germar, 1821) and new diagnostic features of this species are presented. The development cycle of R.neta in the standard conditions lasts almost 60 days: an 11-day egg period, a 29-day larval period, and an 18-day pupal period, on average. The larvae are parasitised by hymenopterans of the superfamily Chalcidoidea. Similarities and differences with Rhinusabipustulata and other species of this genus are presented.

The morphology of the preimaginal stages of Squamapion elongatum (Germar, 1817) (Coleoptera, Curculionoidea, Apionidae) and notes on its biology.

Data on the morphology of the egg, mature larva (L3) and pupa of Squamapion elongatum (Germar, 1817) are presented. The development cycle of this species lasts 51-54 days: a 12-day egg period, a 30-day larval period, and a 12-day pupal period, on average. The larvae are attacked by parasitic hymenopterans of the superfamily Chalcidoidea.