0000000001309502
AUTHOR
Jes Johannesen
showing 41 related works from this author
Genetic structure of Cirsium palustre (Asteraceae) and its role in host diversification of Tephritis conura (Diptera: Tephritidae)
2008
Whether or not a host plant is incorporated into a phytophagous insect's diet depends on both the insect's ability to colonize the novel host and the host plant's susceptibility to the insect. The latter, again, will be influenced by the genetic structure of the host plant. Cirsium palustre (marsh thistle) is heavily infested by the tephritid fly Tephritis conura in northern Britain, whereas infestation is not only absent in southern England, but also absent on the European continent where T. conura is common on other Cirsium. To understand why regional infestation patterns evolve, we studied how genetic structure and phylogeographic ancestry of C. palustre are related to the probability of…
Infection of Bois-Noir tuf-type-I stolbur phytoplasma inHyalesthes obsoletus(Hemiptera: Cixiidae) larvae and influence on larval size
2009
Recent dramatic spread of the grapevine yellows disease Bois Noir (BN) in Germany is above all explained by highly increased abundances of the vector Hyalesthes obsoletus (Hemiptera: Cixiidae) associated to the plant Urtica dioica, the reservoir of the BN pathogen stolbur tuf-type-I. The vector acquires BN-phytoplasma as larvae whilst feeding on the roots of infected U. dioica. To understand the dynamics of the Urticacycle, we tested at what instar larvae become infected and whether infection affects larvae size (i.e. growth) at two sites in the Mosel Valley, Germany. Larvae were tested from infected plants and collected at instar-stages 3, 4 and 5. Larvae at stage 3 were already infected b…
Sympatric diversification vs. immigration: deciphering host-plant specialization in a polyphagous insect, the stolbur phytoplasma vector Hyalesthes o…
2012
The epidemiology of vector transmitted plant diseases is highly influenced by dispersal and the host-plant range of the vector. Widening the vector's host range may increase transmission potential, whereas specialization may induce specific disease cycles. The process leading to a vector's host shift and its epidemiological outcome is therefore embedded in the frameworks of sympatric evolution vs. immigration of preadapted populations. In this study, we analyse whether a host shift of the stolbur phytoplasma vector, Hyalesthes obsoletus from field bindweed to stinging nettle in its northern distribution range evolved sympatrically or by immigration. The exploitation of stinging nettle has l…
Glacial survival and post-glacial recolonization of an arctic-alpine freshwater insect (Arcynopteryx dichroa, Plecoptera, Perlodidae) in Europe
2012
Aim General models for understanding the climate-driven processes of post-glacial colonization in European arctic–alpine species are mainly derived from studies on temperate terrestrial taxa. However, cold-adapted freshwater species may tolerate or even thrive under colder climatic conditions as flowing water habitats are thermally buffered against freezing and extremely cold temperatures. Here, we investigate the European Pleistocene and Holocene history of the arctic–alpine stonefly Arcynopteryx dichroa. Location Europe. Methods We used two genetic data sets (mitochondrial sequence data and nuclear microsatellite data) to investigate the glacial survival and post-glacial recolonization ro…
Impact of vector dispersal and host-plant fidelity on the dissemination of an emerging plant pathogen
2012
International audience; Dissemination of vector-transmitted pathogens depend on the survival and dispersal of the vector and the vector's ability to transmit the pathogen, while the host range of vector and pathogen determine the breath of transmission possibilities. In this study, we address how the interaction between dispersal and plant fidelities of a pathogen (stolbur phytoplasma tuf-a) and its vector (Hyalesthes obsoletus: Cixiidae) affect the emergence of the pathogen. Using genetic markers, we analysed the geographic origin and range expansion of both organisms in Western Europe and, specifically, whether the pathogen's dissemination in the northern range is caused by resident vecto…
Genetic cohesion of Eresus walckenaeri (Araneae, Eresidae) in the eastern Mediterranean
2005
The eresid spider genus Eresus is morphologically and ecologically conservative. At least three species occur in Europe. However, deep genetic divergence among geographical samples within two species, E. cinnaberinus and E. sandaliatus, may suggest more cryptic species. In the present study we investigate the genetic cohesion of the third species, Eresus walckenaeri, throughout its eastern Mediterranean distribution range, relative to the E. cinnaberinus–E. sandaliatus species complex. Eresus walckenaeri specimens were monophyletic. Genetic discreteness of E. walckenaeri in a region of sympatry with its sister species in Greece provides evidence for species integrity of E. walckenaeri withi…
Dispersal history of a spider (Stegodyphus lineatus) across contiguous deserts: vicariance and range expansion
2005
Israel marks a crossroads between three continents encompassing several phytogeographical and zoogeographical zones. In this complex area, the flow of species from different biogeographical regions creates opportunities to study how geographical division and colonization routes affect current distribution and structure of resident populations of organisms associated with desert and arid environments, habitats that may have persisted throughout Pleistocene glacial periods. The present paper analyses the population history of the spider Stegodyphus lineatus in the contiguous Negev and Judean deserts in Israel using allozyme and mtDNA variation. The distinct patterns of variation indicate that…
Larval distributions of the ectoparasitoid waspEurytoma robustarelative to the host tephritid gall flyUrophora cardui
2003
Parasitism may explain the patchy distributions of host populations. The present paper is a study of larval distributions of the parasitoid Eurytoma robusta in galls of the tephritid gall fly Urophora cardui . It focuses on E. robusta ’s choice of U. cardui gall and whether this changes relative to the rate of parasitism. Oviposition patterns were inferred by direct counts of larvae in galls and genetically, for both species, using indirect relatedness estimates between gall-members. Furthermore, rates of parasitism in four populations were monitored for 4 years. The modal distribution of E. robusta larvae per gall was one and independent of the level of parasitism. The mean number of E. ro…
The role of swarming sites for maintaining gene flow in the brown long-eared bat (Plecotus auritus)
2004
Bat-swarming sites where thousands of individuals meet in late summer were recently proposed as 'hot spots' for gene flow among populations. If, due to female philopatry, nursery colonies are genetically differentiated, and if males and females of different colonies meet at swarming sites, then we would expect lower differentiation of maternally inherited genetic markers among swarming sites and higher genetic diversity within. To test these predictions, we compared genetic variance from three swarming sites to 14 nursery colonies. We analysed biparentally (five nuclear and one sex-linked microsatellite loci) and maternally (mitochondrial D-loop, 550 bp) inherited molecular markers. Three m…
Widespread plant specialization in the polyphagous planthopper Hyalesthes obsoletus (Cixiidae), a major vector of stolbur phytoplasma: Evidence of cr…
2018
The stolbur phytoplasma vector Hyalesthes obsoletus is generally considered as a polyphagous species associated with numerous wild and cultivated plants. However, recent research in southeastern Europe, the distribution centre of H. obsoletus and the area of most stolbur-inflicted crop diseases, points toward specific host-plant associations of the vector, indicating specific vector-based transmission routes. Here, we study the specificity of populations associated with four host-plants using mitochondrial and nuclear genetic markers, and we evaluate the evolution of host-shifts in H. obsoletus. Host-plant use was confirmed for Convolvulus arvensis, Urtica dioica, Vitex agnus-castus and Cre…
Performance of Host-Races of the Fruit Fly,Tephritis conuraon a Derived Host Plant, the Cabbage ThistleCirsium oleraceum: Implications for the Origin…
2008
The thistle-infesting fruit fly Tephritis conura Loew (Diptera: Tephritidae) forms host races on the melancholy thistle, Cirsium hetewphyllum (L.) Hill (Asterales: Asteraceae) and the cabbage thistle, Cirsium olemceum (L.). Scop. Previous research indicates that the host shift occurred from C. hetewphyllum to C. oleraceum. In this paper we address whether the host shift involved physiological adaptations by studying oviposition acceptance and survival of the two host races on the derived host C. oleraceum. Performance differed significantly between host races. T. conura originating from C. oleraceum produced adults in 75% of all egg-laying trials in contrast to only 6.6% in T. conura origin…
Invasion biology and host specificity of the grapevine yellows disease vector Hyalesthes obsoletus in Europe
2008
Within the past 10 years, the yellows disease ‘bois noir’ (BN) has become one of the commercially most important diseases of grapevine [ Vitis vinifera L. (Vitaceae)] in Europe. Infection pressure is caused by phytoplasmas of the stolbur 16SrXII-A group that are transmitted by a planthopper vector, Hyalesthes obsoletus Signoret (Homoptera: Auchenorrhyncha). Infestation happens as an accidental side-effect of the feeding behaviour of the vector, as vector and pathogen proliferation is dependent on other plants. In Germany, the increase of BN is correlated with the use of a new host plant by the vector, increase in abundance of the vector on the new host plant, and dissemination of host plant…
Invasion genetics of American cherry fruit fly in Europe and signals of hybridization with the European cherry fruit fly
2013
The American cherry fruit fly is an invasive pest species in Europe, of serious concern in tart cherry productionaswellasforthepotentialtohybridizewiththeEuropeancherryfruitfly,Rhagoletiscerasi L. (Diptera: Tephritidae), which might induce new pest dynamics. In the first European reports, the question arose whether only the eastern American cherry fruit fly, Rhagoletis cingulata (Loew) (Diptera: Tephritidae), is present, or also the closely related western American cherry fruit fly, Rhagoletis indifferens Curran. In this study, we investigate the species status of European populations by comparing these with populations of both American species from their native ranges, the invasion dynamic…
Origin of a sudden mass occurrence of the stolbur phytoplasma vectorHyalesthes obsoletus(Cixiidae) in Austria
2014
The grapevine disease ‘bois noir’ is widespread in European viticulture, but in many regions there is a lack of correspondence between disease spread and abundance of the main insect vector, the planthopper Hyalesthes obsoletus. This was the situation in Austria until 2012, when a mass occurrence of the vector was observed on Urtica dioica, a new host plant for the vector and reservoir plant for the pathogen, stolbur phytoplasma, in this area. Here we analyse the origin of the Austrian vector populations using genetic markers. The origin was unambiguously assigned to two regional populations, and two causes for the population expansion: immigration of East Central European populations and l…
The age and evolution of sociality in Stegodyphus spiders: a molecular phylogenetic perspective
2006
Social, cooperative breeding behaviour is rare in spiders and generally characterized by inbreeding, skewed sex ratios and high rates of colony turnover, processes that when combined may reduce genetic variation and lower individual fitness quickly. On these grounds, social spider species have been suggested to be unstable in evolutionary time, and hence sociality a rare phenomenon in spiders. Based on a partial molecular phylogeny of the genus Stegodyphus , we address the hypothesis that social spiders in this genus are evolutionary transient. We estimate the age of the three social species, test whether they represent an ancestral or derived state and assess diversification relative to s…
EVIDENCE FOR KIN-STRUCTURED GROUP FOUNDING AND LIMITED JUVENILE DISPERSAL IN THE SUB-SOCIAL SPIDER STEGODYPHUS LINEATUS (ARANEAE, ERESIDAE)
2001
Abstract In sub-social spiders, restricted dispersal of young (i.e., natal philopatry) and the potential for inbreeding could contribute to within-population subdivision, thus resulting in a population structure similar to that found in social congeners. In this context, we analyzed the origin and mode of individual distribution patterns and their contribution to within-population structure in juveniles of the sub-social spider Stegodyphus lineatus. We investigated the distribution of juveniles for four months after leaving the maternal nest using allozyme genetic markers. We found that isolated groups of juveniles consisted predominantly of siblings, whereas larger aggregations of individu…
A hierarchical analysis of genetic structure and variability in patchily distributed coexisting Chiastocheta species (Diptera:Anthomyiidae)
1996
The pattern of genetic variation in four coexisting fly species of the genus Chiastocheta was studied by allozyme electrophoresis. The fly species are confined to patches of one plant, Trollius europaeus, and thus experience very similar habitat fluctuations. Collection sites were chosen in a hierarchical fashion and F-statistics were estimated at three levels: intraregion, inter-region and total population. Population characteristic genetic parameters were compared within and among species and were related to the hierarchical level. The species were used as replicate experiments for inference of habitat history, and the hierarchical levels were used as inference for specific gene flow patt…
Morphological adaptation in host races of Tephritis conura
2007
The present study investigates morphological differentiation among host races of the fruit fly Te phritis conura Loew (Diptera: Tephritidae) for two fitness-related traits and whether these traits are host induced or genetically determined. Flies were analyzed from independent sympatric regions, and from one syntopic site where parental host plants [ Cirsium heterophyllum (L.) Hill. and Cirsium oleraceum (L.) Scop. (Cardueae)] and hybrid plants ( C. heterophyllum × C. oleraceum ) co-occur. As both host races may oviposit on hybrid plants and hybrid plants provide an identical environment for larvae of both host races, flies emerging from C. heterophyllum × C. oleraceum hybrids were used to …
Survival relative to new and ancestral host plants, phytoplasma infection, and genetic constitution in host races of a polyphagous insect disease vec…
2014
Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentia…
The significance of relatedness and gene flow on population genetic structure in the subsocial spider Eresus cinnaberinus (Araneae: Eresidae)
1998
Interdemic selection, inbreeding and highly structured populations have been invoked to explain the evolution of cooperative social behaviour in the otherwise solitary and cannibalistic spiders. The family Eresidae consists of species ranging from solitary and intermediate subsocial to species exhibiting fully cooperative social behaviour. In this study we, in a hierarchical analysis, investigated relatedness of putative family clusters, inbreeding and population genetic structure of the subsocial spider Eresus cinnaberinus. Five hierarchical levels of investigation ranging from large scale genetic structure (distances of 250 and 50 km level 1 and 2) over microgeographic structure (20 km 2 …
Parapatric diversification after post-glacial range expansion in the gall flyUrophora cardui(Tephritidae)
2010
Aim Primary and secondary genetic clines in post-glacial colonized regions have different implications for biogeographic distributions and the origin of species. Primary clines arise in situ after colonization as adaptive responses to environmental gradients, while secondary clines are caused by contact between vicariant lineages. Here we analyse primary versus secondary origin of a genetic cline in the tephritid fly Urophora cardui in Jutland, Denmark, in a post-glacial landscape. Location Western Palaearctic. Methods Phylogeographic and demographic analyses of U. cardui based on mitochondrial DNA (mtDNA) genealogies, hierarchical genetic variance tests based on allozymes and distributi…
Social flexibility and social evolution in mammals: a case study of the African striped mouse (Rhabdomys pumilio)
2011
Environmental change poses challenges to many organisms. The resilience of a species to such change depends on its ability to respond adaptively. Social flexibility is such an adaptive response, whereby individuals of both sexes change their reproductive tactics facultatively in response to fluctuating environmental conditions, leading to changes in the social system. Social flexibility focuses on individual flexibility, and provides a unique opportunity to study both the ultimate and proximate causes of sociality by comparing between solitary and group-living individuals of the same population: why do animals form groups and how is group-living regulated by the environment and the neuro-en…
Molecular data and species distribution models reveal the Pleistocene history of the mayfly Ameletus inopinatus (Ephemeroptera: Siphlonuridae)1
2011
SUMMARY 1. We investigated the Pleistocene and Holocene history of the rare mayfly Ameletus inopinatus EATON 1887 (Ephemeroptera: Siphlonuridae) in Europe. We used A. inopinatus as a model species to explore the phylogeography of montane, cold-tolerant aquatic insects with arctic–alpine distributions. 2. Using species distribution models, we developed hypotheses about the species demographic history in Central Europe and the recolonisation history of Fennoscandia. We tested these hypotheses using mitochondrial cytochrome oxidase I (mtCOI) sequence data and compared our genetic results with previously generated microsatellite data to explore genetic diversity distributions of A. inopinatus. …
Evidence for a recent horizontal transmission and spatial spread of Wolbachia from endemic Rhagoletis cerasi (Diptera: Tephritidae) to invasive Rhago…
2013
The widespread occurrence of Wolbachia in arthropods and nematodes suggests that this intracellular, maternally inherited endosymbiont has the ability to cross species boundaries. However, direct evidence for such a horizontal transmission of Wolbachia in nature is scarce. Here, we compare the well-characterized Wolbachia infection of the European cherry fruit fly, Rhagoletis cerasi, with that of the North American eastern cherry fruit fly, Rhagoletis cingulata, recently introduced to Europe. Molecular genetic analysis of Wolbachia based on multilocus sequence typing and the Wolbachia surface protein wsp showed that all R. cingulata individuals are infected with wCin2 identical to wCer2 in …
Population structure and incidence of the stolbur phytoplasma vectorHyalesthes obsoletus(Cixiidae) among geographic regions in Switzerland
2013
The dissemination of stolbur phytoplasma (16Sr-XIIA group)-induced yellows diseases depends on the dispersal biology and host plant fidelity of the planthopper vector Hyalesthes obsoletus (Hemiptera: Cixiidae). We analysed the degree of these two properties in H. obsoletus by studying its population genetic structure and stolbur infection rates relative to the two major host plants, Convolvolus arvensis and Urtica dioica, in order to infer relevant divisions for stolbur epidemiology in Swiss viticultural regions. Three regional populations with the potential to determine stolbur epidemiology in distinct ways were identified. First, populations associated with U. dioica in northern Switzerla…
Mitochondrial DNA distributions indicate colony propagation by single matri-lineages in the social spider Stegodyphus dumicola (Eresidae)
2002
Colony-dwelling social spiders of the genus Stegodyphus are characterized by high colony turnover, within-colony mating, inbreeding and skewed sex ratios. These phenomena may purge genetic variation from the entire species gene pool. Social Stegodyphus have previously been discussed as ecologically unstable and evolutionary dead ends. We investigated the distribution and age (sequence divergence) of mitochondrial DNA variation for inferences of colony propagation, colony discreteness and maintenance of genetic variation in the social spider S. dumicola. In contrast to our expectations, we found abundant mtDNA variation, consisting of 15 haplotypes belonging to four haplotype lineages. Linea…
Analysis of gene flow and habitat patch network for Chazara briseis (Lepidoptera: Satyridae) in an agricultural landscape
1997
Abstract A fine geographic-scale population genetic structure analysis was performed for the endangered butterfly species Chazara briseis in the region of Halle an der Saale, Germany, for the investigation of gene flow and possible effects of habitat fragmentation on genetic variability. Patterns of genetic variance were estimated by allozyme electrophoresis and quantified with F -statistics. Levels of genetic variation were high, expected heterozygosity H e = 0.20, and mean number of alleles per locus, A = 1.93, indicating large population sizes. Butterflies inhabiting the study area probably constituted just one population and the fragmented nature of the habitat patches did not substanti…
Phylogeographic patterns of host-race evolution in Tephritis conura (Diptera: Tephritidae)
2006
Host-race evolution is a prime candidate for sympatric speciation because host shifts must take place in the presence of both hosts. However, the geographic context in which the shift takes place may have strong allopatric or peripatric components if the primary host within a localized area is scarce or even goes extinct. Inference of the relative importance of the geographic mode of speciation may be gained from phylogeographic imprints. Here, we investigate the phylogeography of host races of the tephritid fly Tephritis conura from sympatric, parapatric and allopatric populations of Cirsium heterophyllum and Cirsium oleraceum (Asteraceae) in Europe, for addressing the age and direction, a…
Characterisation of microsatellite and SNP markers from Miseq and genotyping-by-sequencing data among parapatric Urophora cardui (Tephritidae) popula…
2017
Phylogeographic analyses of the gall flyUrophora carduihave in earlier studies based on allozymes and mtDNA identified small-scale, parapatrically diverged populations within an expanding Western Palearctic population. However, the low polymorphism of these markers prohibited an accurate delimitation of the evolutionary origin of the parapatric divergence.Urophora carduifrom the Western Palearctic have been introduced into Canada as biological control agents of the host plantCirsium arvense. Here, we characterise 12 microsatellite loci with hexa-, penta- and tetra-nucleotide repeat motifs and report a genotyping-by-sequencing SNP protocol. We test the markers for genetic variation among thr…
Group founding and breeding structure in the subsocial spider stegodyphus lineatus (Eresidae)
1999
Co-operative behaviour may evolve by enhancing the genetic similarity of group members. Increased group similarity is thought to be the basis for the 'subsocial route' of social evolution in the spider family Eresidae. Two processes may promote the similarity of individuals within populations or breeding groups, namely philopatry in stable environments and founder events in a stochastic environment. We show that both processes led to genetic differentiation within and among populations of the subsocial spider Stegodyphus lineatus. Within populations we distinguished between the genetic structure caused by random mating and philopatry in old breeding groups and that caused by newly founded g…
Distortion of symmetrical introgression in a hybrid zone: evidence for locus-specific selection and uni-directional range expansion
2006
The fate of species integrity upon natural hybridization depends on the interaction between selection and dispersal. The relative significance of these processes may be studied in the initial phase of contact before selection and gene flow reach equilibrium. Here we study a hybrid zone of two salamander species, Lyciasalamandra antalyana and Lyciasalamandra billae, at the initial phase of hybridization. We quantify the degree and mode of introgression using nuclear and mtDNA markers. The hybrid zone can be characterized as an abrupt transition zone, the central hybrid zone being only c. 400 m, but introgressed genes were traced up to 3 km. Introgression was traced in both sexes but gene flo…
Phylogeny of entelegyne spiders: Affinities of the family Penestomidae (NEW RANK), generic phylogeny of Eresidae, and asymmetric rates of change in s…
2010
Penestomine spiders were first described from females only and placed in the family Eresidae. Discovery of the male decades later brought surprises, especially in the morphology of the male pedipalp, which features (among other things) a retrolateral tibial apophysis (RTA). The presence of an RTA is synapomorphic for a large clade of spiders exclusive of Eresidae. A molecular data matrix based on four loci was constructed to test two alternative hypotheses: (1) penestomines are eresids and the RTA is convergent, or (2) penestomines belong within the RTA clade. Taxon sampling concentrated on the Eresidae and the RTA clade, especially outside of the Dionycha and Lycosoidea. Evolution of the c…
Highly asymmetric fine-scale genetic structure between sexes of African striped mice and indication for condition dependent alternative male dispersa…
2011
Sex-biased dispersal is observed in many taxa, but few studies have compared sex-biased dispersal among and within populations. We addressed the magnitude and habitat dependency of sex-biased dispersal in social African striped mice by separating group-related from population-related genetic variance to understand the contribution of each sex to deme structure. As dispersal over unoccupied habitat is likely to be more costly than dispersal within a population, we predicted that individuals leaving the natal population have a lower body condition, being inferior to heavier territorial individuals. Fine-scale genetic structure was detected in both sexes. Female relatedness decreased continuou…
A TEST FOR REPRODUCTIVE SEPARATION OF ALTERNATE GENERATIONS IN A BIENNIAL SPIDER, ARANEUS DIADEMATUS (ARANEAE, ARANEIDAE)
2002
In Denmark, two seemingly distinct size-classes, 3rd and 4th instar juveniles and repro- ductive adults, of Araneus diadematus are found during every breeding season in autumn, indicating a non-overlapping biennial life-cycle. We tested the hypothesis that alternate generations might experience a degree of reproductive isolation, using the distribution of nuclear (allozyme) and maternal (mtDNA) genetic markers. Individuals of a locality behaved as belonging to a random mating population, irrespective of size. No differences were found between any size-class pairs, within and between 2 yr, or among geographically distant samples. Processes that may lead to this result are discussed: the bien…
Speciation via Differential Host–Plant Use in the Tephritid Fly Tephritis conura
2010
The close association between phytophagous insects and host plants and the possibility for specialization on new plants make phytophagous insects prime candidates for sympatric speciation via host-race evolution. In this chapter, we summarize results addressing host-race evolution in the tephritid fly Tephritis conura (Tephritidae) infesting Cirsium heterophyllum and C. oleraceum (Asteraceae). Host plant distributions in allopatry, sympatry and parapatry, and different infestation patterns enabled us to test geographic speciation scenarios, investigate adaptations, and address the importance of plant population history for diversification of T. conura.
Comparative population genetic structures of the fruit flyUrophora carduiand its primary parasitoidEurytoma robusta
2003
The interaction between two species may depend on geographic scale and this in turn can affect co-evolution among them. The present study comparatively examines population genetic structures of the tephritid gall fly Urophora cardui and its primary ectoparasitoid Eurytoma robusta for inference of relative dispersal patterns and host parasitoid specificity. Genetic differentiation patterns indicated two levels of hierarchical structure in both species: locally similar distance-dependencies but globally differences. Locally, both species showed isolation by distance and a high correlation between host anti parasitoid F ST for the same population-pairs was found. At the local level, E. robusta…
Data from: Sympatric diversification vs. immigration: deciphering host-plant specialization in a polyphagous insect, the stolbur phytoplasma vector H…
2013
The epidemiology of vector transmitted plant diseases is highly influenced by dispersal and the host-plant range of the vector. Widening the vector's host range may increase transmission potential, whereas specialization may induce specific disease cycles. The process leading to a vector's host shift and its epidemiological outcome is therefore embedded in the frameworks of sympatric evolution vs. immigration of preadapted populations. In this study, we analyse whether a host shift of the stolbur phytoplasma vector, Hyalesthes obsoletus from field bindweed to stinging nettle in its northern distribution range evolved sympatrically or by immigration. The exploitation of stinging nettle has l…
Data from: Highly asymmetric fine-scale genetic structure between sexes of African striped mice and indication for condition dependent alternative ma…
2011
Sex-biased dispersal is observed in many taxa, but few studies have compared sex-biased dispersal among and within populations. We addressed the magnitude and habitat dependency of sex-biased dispersal in social African striped mice by separating group-related from population-related genetic variance to understand the contribution of each sex to deme structure. As dispersal over unoccupied habitat is likely to be more costly than dispersal within a population, we predicted that individuals leaving the natal population have a lower body condition, being inferior to heavier territorial individuals. Fine-scale genetic structure was detected in both sexes. Female relatedness decreased continuou…
Data from: Characterisation of microsatellite and SNP markers from Miseq and genotyping-by-sequencing data among parapatric Urophora cardui (Tephriti…
2018
Phylogeographic analyses of the gall fly Urophora cardui have in earlier studies based on allozymes and mtDNA identified small-scale, parapatrically diverged populations within an expanding Western Palearctic population. However, the low polymorphism of these markers prohibited an accurate delimitation of the evolutionary origin of the parapatric divergence. Urophora cardui from the Western Palearctic have been introduced into Canada as biological control agents of the host plant Cirsium arvense. Here, we characterise 12 microsatellite loci with hexa-, penta- and tetra-nucleotide repeat motifs and report a genotyping-by-sequencing SNP protocol. We test the markers for genetic variation amon…
Data from: Evidence for a recent horizontal transmission and spatial spread of Wolbachia from endemic Rhagoletis cerasi (Diptera: Tephritidae) to inv…
2013
The widespread occurrence of Wolbachia in arthropods and nematodes suggests that this intracellular, maternally inherited endosymbiont has the ability to cross species boundaries. However, direct evidence for such a horizontal transmission of Wolbachia in nature is scarce. Here, we compare the well-characterized Wolbachia infection of the European cherry fruit fly, Rhagoletis cerasi, with that of the North American eastern cherry fruit fly, Rhagoletis cingulata, recently introduced to Europe. Molecular genetic analysis of Wolbachia based on multilocus sequence typing and the Wolbachia surface protein wsp showed that all R. cingulata individuals are infected with wCin2 identical to wCer2 in …
Data from: Survival relative to new and ancestral host plants, phytoplasma infection and genetic constitution in host races of a polyphagous insect d…
2015
Dissemination of vectorborne diseases depends strongly on the vector's host range and the pathogen's reservoir range. Because vectors interact with pathogens, the direction and strength of a vector's host shift is vital for understanding epidemiology and is embedded in the framework of ecological specialization. This study investigates survival in host-race evolution of a polyphagous insect disease vector, Hyalesthes obsoletus, whether survival is related to the direction of the host shift (from field bindweed to stinging nettle), the interaction with plant-specific strains of obligate vectored pathogens/symbionts (stolbur phytoplasma), and whether survival is related to genetic differentia…