Differences in the karyology of two species, Centricnemus leucogrammus and Peritelus familiaris (Coleoptera: Curculionidae), were investigated in order to elucidate their taxonomic position of the taxa. Previously both species were placed in one genus whereas the latest taxonomic revision puts them in separate genera. Cytogenetic analysis of P. familiaris and C. leucogrammus showed significant differences in karyotype structure and confirmed their present taxonomic status. The diploid set of C. leucogrammus consists of 22 chromosomes with a fundamental number of arms (FN) of 45 and little variation in morphology and length. Peritelus familiaris has 24 chromosomes with FN of 47 and a more diverse karyotype. The karyotype evolution might have occured by centric fissions of autosomes. At pachytene and diplotene in spermatocytes, each chromosome bivalent showed a small band of pericentric heterochromatin. The bands were hardly visible or undetectable in other stages of spermatogenesis, namely mitotic metaphase, diakinesis, metaphase I and II. The nucleolar organizer regions (NORs) were active at premeiotic stages and early meiosis, but invisible at meiotic metaphase I, metaphase II, and mitotic metaphase. These results indicate the usefulness of cytogenetic methods in taxonomic evaluations.
Phylogeography, genetic diversity, and demography of central European populations of two flightless xerothermic weevils, Polydrusus inustus and Centricnemus leucogrammus, were studied based on the polymorphism of three mtDNA genes (COII, CytB, and ND1). Results indicate that these xerothermic beetles may have different origins. P. inustus is a recent migrant as the parthenogenetic form has a low level of genetic diversity and lacks a geographic population structure. This is probably a result of a recent (before the end of last glaciation) expansion and/or present dispersal mediated by humans. On the other hand, C. leucogrammus appears to be a relic species as the populations of this species are much more genetically diverse (six distinct clades) and some of the populations are allopatric and others sympatric. They probably diverged and expanded during the last few glaciations. Genetic discontinuities were detected among localities that are now separated by gaps in the distribution. Boundaries (mountains or farmland) separate the populations into three groups: (1) Moravia and Slovakia, (2) the lower Vistula Valley in northern Poland and (3) south-eastern Poland together with western Ukraine. Evidence for recent gene flow was found only among populations from south-eastern Poland and western Ukraine, and between these two groups. One population from northern Poland was surprisingly related to populations in southern Poland, which may be due to extinction of intermediate populations.
Intracellular bacteria of the genus Wolbachia (α-Proteobacteria) are the most widespread endosymbionts of insects. Host infection is usually associated with alterations in reproduction, such as cytoplasmic incompatibility, the induction of parthenogenesis and offspring sex ratio bias: all phenomena that may influence host speciation. In the present study, by using well-established molecular tools, we investigated the presence of Wolbachia in leaf beetles of the genus Crioceris and their host plants, which are various species of Asparagus. Multilocus sequence typing of bacterial genes showed that despite their occurrence in the same habitat and feeding on the same plant, two species of Crioceris, C. quinquepunctata and C. quatuordecimpunctata, are infected by two different strains of Wolbachia. C. asparagi, C. paracenthesis and C. duodecimpunctata, which are sympatric with the infected species, do not harbour the bacterium. Interestingly, DNA of Wolbachia was detected in host plant tissues that are exploited by the beetles, providing evidence for the horizontal transmission of the bacterium between beetles and their host plants. Moreover, Wolbachia was detected in species of Crioceris that are not closely related., Michał Kolasa, Matteo Montagna, Valeria Mereghetti, Daniel Kubisz, Miłosz A. Mazur, Łukasz Kajtoch., and Obsahuje bibliografii