ALLOMETRIC SHAPE CHANGES INDICATE SIGNIFICANT DIVERGENCE IN THE WING SHAPE BETWEEN ASEXUAL AND SEXUAL LINEAGES OF LYSIPHLEBUS FABARUM (MARSHALL) (HYMENOPTERA: BRACONIDAE)

We used landmark-based geometric morphometrics to explore and quantify the forewing shape variation between asexual and sexual lineages of Lysiphlebus fabarum aphid parasitoids. We found a significant divergence in wing size and wing shape between the two reproductive lineages. Static allometry, which denotes size-related shape changes measured in different individuals at the same developmental stage within a population or species, accounts for the significant amount of variation in wing shape within each lineage (11.16 % in asexual, 7.5% in sexual). The allometric shape changes appear to be lineage specific, i.e., the allometric slopes of wing shape significantly diverge between lineages. Such a pattern indicates that asexual and sexual lineages differ in the covariation pattern of the wing shape. Further studies on larger datasets, including other Lysiphlebus taxa and closely related groups, would shed more light on the pattern of morphological variation and the significance of the reproductive mode on the morphological evolution of parasitoid wasps

Identification of Two Cryptic Species within the Praon abjectum Group (Hymenoptera: Braconidae: Aphidiinae) Using Molecular Markers and Geometric Morphometrics

The genus Praon represents a large group of aphid endoparasitoids and is exemplary for the problems encountered in their taxonomy because of a great variability of morphological characters. To investigate the intraspecific variability and to ascertain cryptic speciation within the Praon abjectum Haliday group, biotypes in association with the aphid hosts Aphis sambuci L., Longicaudus trirhodus Walker, and Rhopalosiphum spp. were examined. We combined molecular and geometric morphometric analyses, that is, partial sequences of the mitochondrial cytochrome oxidase subunit I and nuclear 28SD2 genes and the shape of the forewing. Low variation of 28SD2 sequences confirmed the close relatedness of species from the genus Praon. Analysis of the cytochrome oxidase subunit I sequences however identified three separate taxa within the P. abjectum group with substantial genetic divergence. The biotype of P. abjectum associated with L. trirhodus differed from those associated with Rhopalosiphum sp. and A. sambuci by 5.4-6.5% and 7.7% sequence divergence, respectively, while the genetic distance between the latter two biotypes ranged from 9.5 to 10%. The main changes in the forewing shape that discriminate these three biotypes as revealed by geometric morphometrics are related to the stigma shape and the position of the radial nerve. Based on the differences determined in mitochondrial sequences and in the shape of the wing, we describe two new cryptic species within the P. abjectum group as follows: P. sambuci sp. n. in association with A. sambuci/S. nigra and P. longicaudus sp. n. in association with L. trirhodus/T. aquilegifoliu

Slovanský literární svět: kontexty a konfrontace III

Title in English: Slavonic Literary World: Contexts and Confrontations III: Motif of home in Slavonic literatures. Post-conference proceedings “Slavonic Literary World: Contexts and Confrontations III” with the subtitle “Motif of home in Slavonic literatures” consists of 15 papers of doctoral students from 5 European countries. In compliance with the thematic focus of the conference the authors deal with the motif of home in variety of connections, therefore their works bring the new impulses to present state of knowledge and their works illustrates the tendencies and directions of young generation of Slavists

Wing shape as a taxonomic trait: separating genetic variation from host-induced plasticity in aphid parasitoids

Separating environmental effects on an organism's phenotype from genetic effects is not only of evolutionary interest, but also important in morphological taxonomy. Ideally, morphological traits to distinguish species are robust to environmental variation. In taxonomically difficult groups of insects such as aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae), wing shape quantified by geometric morphometrics is increasingly used to distinguish cryptic species that are difficult to separate with other morphological characters. However, aphid parasitoids may use multiple host species; the validity of this approach thus hinges on wing shape being a genetically hard-wired trait that is not strongly moulded by the host in which the parasitoid develops. The occurrence of asexual lines in the aphid parasitoid Lysiphlebus fabarum (Marshall) provides an opportunity to test this assumption by rearing genetically identical individuals in different environments. We reared five asexual lines of L. fabarum in four different aphid species to quantify the relative importance of these factors on parasitoid wing shape. We found that the parasitoid genotype explains a much larger proportion of the observed variation in wing shape than the host species. The host also significantly affected wing shape, but to a lesser extent, and largely via an effect on size (allometry), which can be corrected for. Our study shows that even at the level of lineages within a single species, the influence of the host environment is small relative to the genetic determination of wing shape, thus validating the use of this trait for taxonomic purposes

Molecular and morphological variation among the European species of the genus Aphidius Nees (Hymenoptera: Braconidae: Aphidiinae)

The main objective of the present paper was to analyse and compare the patterns of molecular and morphological divergence of European parasitoid wasps belonging to the diverse genus Aphidius Nees, 1818. The maximum likelihood and maximum parsimony trees constructed by including 64 different haplotypes of the barcoding region of mitochondrial cytochrome oxidase subunit I (mtCOI) identified for 33 Aphidius species showed identical topology. A high level (99%) of bootstrap support was found for the phylogenetic line consisting of A. ribis Haliday, 1834, A. chaetosiphonis Tomanović & Petrović, 2011 and A. hortensis Marshall, 1896, and for the group consisting of A. colemani Vierck, 1912, A. transcaspicus Telenga, 1958, A. asteris Haliday, 1834 and A. platensis Brethes, 1913. The remaining lineages on the trees were not significantly supported. We applied the approach of geometric morphometrics to explore morphological divergences in forewing size. A significant difference of mean wing shape was found between Aphidius species. The observed low resolution of the mtCOI gene of morphologically and ecologically well-defined Aphidius species is probably due to species hybridisation followed by introgression of mtDNA. Despite low resolution of the phylogenetic tree, the permutation test for a phylogenetic signal in wing shape was statistically significant, indicating that phylogenetically more closely related species are more similar than unrelated ones. A clear agreement between molecular and morphological variation was determined only for the two phylogenetically well-resolved groups

Identification of two cryptic species within the praon abjectum group (Hymenoptera: Braconidae: Aphidiinae) using molecular markers and geometric morphometrics

The genus Praon represents a large group of aphid endoparasitoids and is exemplary for the problems encountered in their taxonomy because of a great variability of morphological characters. To investigate the intraspecific variability and to ascertain cryptic speciation within the Praon abjectum Haliday group, biotypes in association with the aphid hosts Aphis sambuci L., Longicaudus trirhodus Walker, and Rhopabsiphum spp. were examined. We combined molecular and geometric morphometric analyses, that is, partial sequences of the mitochondrial cytochrome oxidase subunit I and nuclear 28SD2 genes and the shape of the forewing. Low variation of 28SD2 sequences confirmed the close relatedness of species from the genus Praon. Analysis of the cytochrome oxidase subunit I sequences however identified three separate taxa within the P. abjectum group with substantial genetic divergence. The biotype of P. abjectum associated with L. Trirhodus differed from those associated with Rhopabsiphum sp. and A. sambuci by 5.4-6.5% and 7.7% sequence divergence, respectively, while the genetic distance between the latter two biotypes ranged from 9.5 to 10%. The main changes in the forewing shape that discriminate these three biotypes as revealed by geometric morphometrics are related to the stigma shape and the position of the radial nerve. Based on the differences determined in mitochondrial sequences and in the shape of the wing, we describe two new cryptic species within the P. abjectum group as follows: P. sambuci sp. n. in association with A. sambuci/S. nigra and P. longicaudus sp. n. in association with L. Trirhodus/T. aquilegifolium. © 2013 Entomological Society of America

Wing shape as a taxonomic trait: separating genetic variation from host-induced plasticity in aphid parasitoids

Separating environmental effects on an organism's phenotype from genetic effects is not only of evolutionary interest, but also important in morphological taxonomy. Ideally, morphological traits to distinguish species are robust to environmental variation. In taxonomically difficult groups of insects such as aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae), wing shape quantified by geometric morphometrics is increasingly used to distinguish cryptic species that are difficult to separate with other morphological characters. However, aphid parasitoids may use multiple host species; the validity of this approach thus hinges on wing shape being a genetically hard-wired trait that is not strongly moulded by the host in which the parasitoid develops. The occurrence of asexual lines in the aphid parasitoid Lysiphlebus fabarum (Marshall) provides an opportunity to test this assumption by rearing genetically identical individuals in different environments. We reared five asexual lines of L. fabarum in four different aphid species to quantify the relative importance of these factors on parasitoid wing shape. We found that the parasitoid genotype explains a much larger proportion of the observed variation in wing shape than the host species. The host also significantly affected wing shape, but to a lesser extent, and largely via an effect on size (allometry), which can be corrected for. Our study shows that even at the level of lineages within a single species, the influence of the host environment is small relative to the genetic determination of wing shape, thus validating the use of this trait for taxonomic purposes

Trust, disruption and responsibility in accounts of injecting equipment sharing and hepatitis C risk

Accounts of health-related risk behaviour are generated in a social context of risk acceptability and moral responsibility. Drawing upon qualitative semi-structured interviews with injecting drug users (IDUs) in Belgrade, Serbia (n=67) and Podgorica and Bar, Montenegro (n=32), we explore drug injectors' accounts of sharing injecting equipment, and 'discriminative' and 'exceptional' sharing specifically, alongside accounts of hepatitis C risk. We find that accounts emphasize discriminative and exceptional sharing as acceptable given the circumstances, with normative syringe sharing presented as unacceptable and irresponsible. Two key themes emerged in descriptions of discriminative and exceptional sharing: 'trust' based in social relations, ensuring that sharing took place under 'reduced risk' conditions; and 'disruptions' to safety routine brought about by accidents, unexpected events, drug withdrawal and the environment. In accounts of environmental disruption, a lack of trust (and blame) was identified in relation to pharmacies and police. Whereas trust accounts justified sharing as reduced risk, disruption accounts accepted risk opportunity but appealed to a denial of agency. In addition, accounts portrayed a general context of risk and uncertainty in relation to hepatitis C, characterized by a lack of trust in knowledge about others' disclosed antibody status, a lack of faith in expert helping systems and confusion about HCV transmission

Genetic and morphological variation in sexual and asexual parasitoids of the genus Lysiphlebus - An apparent link between wing shape and reproductive mode

© 2015 Petrovic et al.; licensee BioMed Central. Background: Morphological divergence often increases with phylogenetic distance, thus making morphology taxonomically informative. However, transitions to asexual reproduction may complicate this relationship because asexual lineages capture and freeze parts of the phenotypic variation of the sexual populations from which they derive. Parasitoid wasps belonging to the genus Lysiphlebus Foerster (Hymenoptera: Braconidae: Aphidiinae) are composed of over 20 species that exploit over a hundred species of aphid hosts, including many important agricultural pests. Within Lysiphlebus, two genetically and morphologically well-defined species groups are recognised: the fabarum and the testaceipes groups. Yet within each group, sexual as well as asexual lineages occur, and in L. fabarum different morphs of unknown origin and status have been recognised. In this study, we selected a broad sample of specimens from the genus Lysiphlebus to explore the relationship between genetic divergence, reproductive mode and morphological variation in wing size and shape (quantified by geometric morphometrics). Results: The analyses of mitochondrial and nuclear gene sequences revealed a clear separation between the testaceipes and fabarum groups of Lysiphlebus, as well as three well-defined phylogenetic lineages within the fabarum species group and two lineages within the testaceipes group. Divergence in wing shape was concordant with the deep split between the testaceipes and fabarum species groups, but within groups no clear association between genetic divergence and wing shape variation was observed. On the other hand, we found significant and consistent differences in the shape of the wing between sexual and asexual lineages, even when they were closely related. Conclusions: Mapping wing shape data onto an independently derived molecular phylogeny of Lysiphlebus revealed an association between genetic and morphological divergence only for the deepest phylogenetic split. In more recently diverged taxa, much of the variation in wing shape was explained by differences between sexual and asexual lineages, suggesting a mechanistic link between wing shape and reproductive mode in these parasitoid wasps

Two new species of aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae) from the Balkan Peninsula

Two new species of aphid parasitoids from the Balkan Peninsula are described. Aphidius chaetosiphonis sp. n. was reared from Chaetosiphon sp./Potentilla clusiana, while Aphidius balcanicus sp. n. was reared from Acyrthosiphon malvae / Geranium spp. associations. The taxonomic position of both species has been discussed