Aim The bush‐cricket Metrioptera roeselii is an example of an insect which has expanded its indigenous range beyond expectations based on its natural dispersal potential. Understanding how species colonize new areas is vital for formulating effective species conservation programmes and managing invasive species. The aim of this research is to use mitochondrial sequence and microsatellite data to delineate the likely origin and dispersal pathways of M. roeselii in northern Europe. The well‐known ecology of the species and the detailed colonization data make it a very suitable model species for addressing questions relating to invasiveness. Location Fennoscandia, Baltic Sea coast, northern Europe. Methods Using a 676 bp fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene and seven polymorphic microsatellite loci, we genotyped and compared populations at 28 sites within the continuous range of M. roeselii along the Baltic Sea coast, and 10 isolated populations in Denmark, islands in the Baltic Sea and the Scandinavian Peninsula. The acquired data, information on the species' ecology and historical population establishment records were used to infer the colonization history and pathways of this species. Results Both mitochondrial DNA and microsatellite data indicated that several of the isolated populations did not originate from their nearest locations within the continuous distribution area of M. roeselii. Instead, the likeliest source populations were in some cases situated > 500 km from the isolated populations. Hence the first records of appearance in the isolated sites did not coincide with the species' natural expansion but agreed well with the time of colonization of the founder sites inferred from the genetic data. Main conclusions The limited ability of M. roeselii to cross geographical barriers through active dispersal, the inferred colonization pathways from this study, and the knowledge that transport of eggs can potentially occur with agricultural products collectively suggest that at least some of the isolated populations originate from human‐mediated introductions rather than natural dispersal.

Although two cryptic pipistrelle bat species, Pipistrellus pipistrellus and Pipistrellus pygmaeus, belong among the most common bat species in Europe, it is still unclear whether they can migrate over long distances between summer and winter roosts. Long-distance migratory species may be expected to show low levels of genetic structuring in large areas due to regular mixing of the gene pool by mating that occurs during migration and/or hibernation. Conversely, the dispersal of gametes in sedentary species is spatially restricted, populations are more genetically structured, and isolation by relatively short distance is visible. By analysing diversity of highly variable microsatellites within and among summer colonies of both studied species in central Europe, we found that differentiation between populations is very weak. Both classical FST and Bayesian clustering approach failed to detect genetic structure among colonies and there was no significant isolation-by-distance pattern. The analyses of relatedness, however, revealed that individuals within colonies are more related than random suggesting philopatry of at least one sex. The results were very similar for the two species. The high level of gene flow among central European populations, even on large geographic distances, is discussed in relation with migrations, dispersal, and mating behaviour.

Variation in morphological traits along latitudinal gradients often manifests as size clines. In insects, both positive and negative correlations are seen, and the mechanism behind the response is unclear. We studied variation in seven morphological traits of Roesel's bush cricket, Metrioptera roeselii, sampled from seven latitude-matched-pair populations that were either geographically isolated from or connected to the species continuous distribution range. The aim was to examine whether morphological traits differed between isolated and continuous populations, and whether latitudinal variation was apparent. The data were used to indicate whether variation in trait means originates from plastic responses to the environment or genetic adaptation to local conditions. To evaluate the influence of gene flow on trait means, we analysed the genetic variation in seven microsatellites. Data showed that individuals from isolated populations display a positive relationship between latitude and body size, whereas individuals from continuous populations show little or no such relationship. The combined morphological and genetic data suggest that the isolated populations have adapted to local optima, while gene flow between continuous populations appears to counteract this process.

Newly founded isolated populations need to overcome detrimental effects of low genetic diversity. The establishment success of a population may therefore depend on various mechanisms such as assortative mating, purging of deleterious alleles, creation of new mutations and/or repeated inflow of new genotypes to reduce the effects of inbreeding and further loss of genetic variation. We compared the level of genetic variation in introduced populations of an insect species (Metrioptera roeselii) far beyond its natural distribution with levels found in their respective founder populations and coupled the data with timing since establishment. This allowed us to analyze if the introduced populations showed signs of temporal changes in genetic variation and have made it possible to evaluate underlying mechanisms. For this, we used neutral genetic markers, seven microsatellite loci and a 676–bp-long sequence of the mtDNA COI gene. All tested indices (allelic richness, unbiased expected heterozygosity, effective size, haplotype diversity, and nucleotide diversity) except inbreeding coefficient had significantly higher values in populations within the founding populations inside the continuous area of the species distribution compared with the introduced populations. A logarithmic model showed a significant correlation of both allelic richness and unbiased expected heterozygosity with age of the isolated populations. Considering the species' inferred colonization history and likely introduction pathways, we suggest that multiple introductions are the main mechanism behind the temporal pattern observed. However, we argue that influences of assortative mating, directional selection, and effects of an exceptional high intrapopulation mutation rate may have impacts. The ability to regain genetic diversity at this level may be one of the main reasons why M. roeselii successfully continue to colonize northern Europe.

No abstract

For the assessment of the habitat use of bats with consideration of a complexity of environmental features a largescale multivariate canonical correspondence analysis (CCA) was performed. Data were collected in April-September (1999 using mist-netting and bat-detectors (n ¼ 209 samplings) in Slovakia (n ¼ 160 sites). For the habitat description, 17 environmental variables that characterised the sampling site, tree-species composition and general character of surrounding forest were selected. In study sites, altogether 93% of Slovak chiropterofauna species were recorded but only 16 species (2466 individuals) were recorded in more than 5% of samplings. The most common and frequent species were Myotis mystacinus (frequency of occurrence ¼ 57%, species dominance ¼ 12%) and Myotis myotis (44%, 10%), followed by Barbastella barbastellus (32%, 6%), Plecotus auritus (32%, 6%), Nyctalus noctula (31%, 9%) and Myotis brandtii (31%, 7%). Of the tested environmental variables used in CCA analysis, 13 had significant influence on the species' presence. On the base of gradients in ordination analysis, there were two main groups of species. In the first ''true'' forest bats group the tree-dwelling and gleaning species Myotis bechsteinii, Myotis nattereri and P. auritus dominated. Their occurrence was connected mainly with old forests of natural tree-species composition. The second group comprised species, which foraged in more open space or along the forest edge (with the farmland) and avoided closed interior (particularly Eptesicus serotinus, N. noctula, Nyctalus leisleri, Pipistrellus pipistrellus). The presence of mountain species Eptesicus nilssonii and Vespertilio murinus was associated mainly with dominance of spruce. Suggested predictive modelling of species composition in forest bat assemblages in conditions of natural forests can help in nature conservation.

This article documents the addition of 139 microsatellite marker loci and 90 pairs of singlenucleotide polymorphism sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Aglaoctenus lagotis, Costus pulverulentus, Costus scaber, Culex pipiens, Dascyllus marginatus, Lupinus nanus Benth, Phloeomyzus passerini, Podarcis muralis, Rhododendron rubropilosum Hayata var. taiwanalpinum and Zoarces viviparus. These loci were cross-tested on the following species: Culex quinquefasciatus, Rhododendron pseudochrysanthum Hay. ssp. morii (Hay.) Yamazaki and R. pseudochrysanthum Hayata. This article also documents the addition of 48 sequencing primer pairs and 90 allele-specific primers for Engraulis encrasicolus. et al.

In May -August, bats were mist-netted along an altitudinal gradient of 350-1350 m a.s.l. in the Poľana Mts area, to verify the correlation of species number decrease and the increase in elevation, to find which species could be predictors of certain altitude levels and to compare the sexual occurrence of species in various altitudes. Seventeen bat species were recorded. The most abundant mist-netted species were Myotis daubentonii (16%), M. myotis (13%) and M. mystacinus (12%). Otherwise, the most frequently caught species were M. mystacinus (40%), Eptesicus serotinus, M. myotis (26%) and Nyctalus leisleri (23%). In this study at a local scale, from oak to spruce vegetation stages, decreasing number of species with increasing altitude was found. Species dominance of the individual altitudinal levels was significantly different (15 species up to 600 m a.s.l., six species over 1100 m a.s.l.). The results indicated that the occurrence of some bat species, due to their ecological adaptations, is more or less characteristic for higher or lower altitudes of the Western Carpathians. The "lowland" species were considered to be mainly E. serotinus, Pipistrellus pipistrellus, N. noctula, N. leisleri and M. daubentonii. In higher elevations (more than 850 m), the presence of reproductive females was not found, of all but one, N. noctula, of the "lowland" species which are breeding in the area. The "mountain" species were considered to be E. nilssonii and Plecotus auritus. The general occurrence and reproduction of M. mystacinus and Barbastella barbastellus, was not limited by elevation.