Search

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. [ABSTRACT FROM AUTHOR]

Key message: Higher solar radiation leads to higher crown temperatures, sap flow, and airborne volatile concentrations as well as altered bark chemical composition in trees at fresh forest edge. Spruce bark beetles are likely to attack trees that are at newly opened forest edges after wind disturbance due to higher temperatures and higher emission of primary attractants. The mechanisms behind these phenomena are still not fully known. We investigated how sudden gap creation affects tree physiology parameters related to induced defence processes in Norway spruce trees 2 months after the disturbance driven gap formation. We hypothesized that the sudden sun exposure of mature spruce trees would increase: (1) bark and crown temperatures, (2) sap flow rates, and (3) the phloem and airborne concentration of terpenes. Using a terrestrial and airborne thermal camera, sap flow sensors, and chromatography, we confirmed that trees at the forest edge had significantly higher (1) mean tree crown temperature, (2) mean sap flow rates (2-fold higher) and (3) airborne concentration of α-pinene (αP, 12.2-fold higher) and β-pinene (βP, 7.9-fold higher) close to the bark. We observed a significant positive correlation (R2 = 0.77) between the measured sap flow rates and terpene concentrations in airborne samples. Bark temperatures were not significant. In the phloem samples, analyzed by GC–MS, αP and βP predominated over monoterpenes 3-carene, myrcene, limonene, 1.8-cineole, and bornyl acetate. GC × GC–TOF–MS analysis of phloem showed a higher relative abundance of resin acid methyl esters in the forest interior trees and higher relative abundances of dehydro-p-cymene in the trees at the forest edge. Our findings are discussed in the context of the enhanced predisposition of trees at the newly formed forest edge to bark beetles attack. [ABSTRACT FROM AUTHOR]

Palaearctic steppes evolved under the Cenozoic cold arid climate and megaherbivore pressure. A large portion of the biome persisted into the Holocene but has recently been subjected to human land use alternation. Pseudophilotes bavius (Lepidoptera: Lycaenidae) is a steppe specialist sporadically distributed in Eastern Europe and Pontic-Caspian region (from Transylvania to Southern Urals), the Balkans, the South-Eastern Mediterranean and Irano-Anatolian regions. We used samples covering the distribution area to assess the phylogeography and population genetics of the species based on one mitochondrial and four nuclear genes. The basal lineages are situated in the Irano-Anatolian region, forming two Evolutionary Units. The species radiated to the Balkans and Pontic-Caspian steppes probably when the climatic conditions became suitable after the mid-Pleistocene transition and formation of vast steppe biome. In these parts of the range, the species survived both glacial and interglacial periods in situ, forming a third Evolutionary Unit. In the Balkans, the individual populations are distinct and have probably been isolated for a long time, owing to the diversity of Balkan habitats. In the Pontic-Caspian region, population connectivity probably existed until recently, since the life history of the species is unlikely to include long-distance dispersal. The distribution could have become fragmented with the conversion of steppes into cropland during the past centuries. Future conservation will require proper knowledge of the distribution and habitat needs of the species. Management of inhabited sites should respect historical disturbance-succession dynamics. [ABSTRACT FROM AUTHOR]

A characteristic butterfly of Asian steppes, Proterebia afra (Fabricius 1787), was studied in its two relic areas of occurrence within the Balkans-the Askion Mts (a single mountain massif in NW Greece) and Dalmatia (karstic inland S Croatia)-together with co-occurring butterfly communities during its early spring adult flight period. P. afra adults tolerate harsh continental conditions prevailing at its localities during its flight. Local densities were higher in the Askion Mts (up to 100 individuals per 50 m walk) than in Dalmatia (up to 30 individuals per 50 m). Within both areas of occurrence, it inhabits dry grasslands subject to intermediate grazing pressure that retains enough dry grass litter but still suppresses shrubs and trees. Hotter slopes are preferred in more northerly Dalmatia than in the more southerly Askion Mts. More co-occurring butterfly species and more Mediterranean species were recorded in the Askion Mts (69 vs 63; 23 vs 12), but more butterfly individuals and higher species' richness per transect were observed in Dalmatia. In ordination analyses, the main gradients organising the grassland butterfly communities distinguished between grassy plains and rocky slopes containing more woody plants. Given the distribution extents, local densities and present land use conditions, the Balkan P. afra is not currently endangered, but this may swiftly change with grazing abandonment, especially in Dalmatia, and some conservation actions should be considered in the near future. [ABSTRACT FROM AUTHOR]

The article offers information on a research study analyzing varying perceptions of people belonging to different cultures and society, about animals. Under this study, researchers gathered the views of people residing in five different continents on boid snakes, and compared their aesthetic preferences.

Understanding dispersal ability of an invasive species is crucial for describing its potential spread. Despite this, we still know little about the dispersal potential of many invasive species. We explored dispersal spectra in Pinus strobus, an invasive tree in sandstone areas in Central Europe. We studied dispersal of the species using distribution of self-sown trees in the field. We compared these observed data with theoretical dispersal curves derived using information on wind speed, seed terminal velocity and tree height. Finally, we fitted various empirical dispersal curves to the observed data. All the analyses based on the observed field data were done for the whole dataset, and for the dataset divided by habitat types and age categories of the self-sown trees. P. strobus seeds can disperse up to 757.5 m from the source. The observed data fall within the confidence intervals of the predictions based on a negative exponential model. When comparing different dispersal functions fitted to the data, it was not easy to decide which of the dispersal curves provides the overall best fit. This was because different functions were the best predictors of different parts of the dispersal curve. We suggest that future studies should provide not only empirical fitted dispersal curves but also observed data and provide estimates of confidence intervals. Such information will provide insights into the reliability of the dispersal estimates in general and help to evaluate the predictive power of the different models. [ABSTRACT FROM AUTHOR]

Animals are ancestrally important stimuli for humans who pay disproportional attention to animal objects and exhibit an outstanding ability to categorize animal species, especially those most relevant to them. Humans as well as other primates perceive snakes as ambivalent stimuli that elicit unspecific arousal and attention. We assessed human aesthetic preferences toward milk snakes, the traditional model for studies of Batesian mimicry. The genus is fairly uniform in size and shape, but includes a great variety of color forms; some possessing aposematic patterns while others being rather cryptic. This provides an opportunity to test which features are responsible for positive aesthetic evaluation of the species. We asked the respondents to rank 34 pictures of milk snakes according to perceived beauty. The sets (whole bodies, heads, and skin fragments) covered most of naturally occurring variation in milk snake appearance. While ranking the beauty, the respondents spontaneously classified the species according to two dimensions. In each set, one of the dimensions corresponds to perceived beauty. The respondents' ranking revealed several distinct clusters of species instead of a continuous gradient. The species clustered in a similar way irrespective of evaluated set. One dimension of the ranking associated with the relative representation of red color and the number of transversal stripes, the other corresponded to a low proportion of red and a high proportion of black color. When the whole body of the snake is evaluated, aposematic coloration contributes to its perceived beauty. In conclusion, humans showed a surprising ability to classify milk snake patterns; they repeatedly formed the same distinct groups of species, thus completing a process that resembles unsupervised categorization. [ABSTRACT FROM AUTHOR]