| 1. |
- Ekbom, Barbara, et al.
(författare)
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Consumption of flea beetles (Phyllotreta, Coleoptera: Chrysomelidae) by spiders in field habitats detected by molecular analysis
- 2014
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Ingår i: Canadian Entomologist. - : Cambridge University Press (CUP). - 0008-347X .- 1918-3240. ; 146, s. 639-651
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Tidskriftsartikel (refereegranskat)abstract
- Flea beetles, Phyllotreta Chevrolat (Coleoptera: Chrysomelidae) species, are often found in oilseed rape (OSR), Brassica napus Linnaeus (Brassicaceae). Among predators in the generalist predator complex present in agricultural fields, wolf spiders (Araneae: Lycosidae) are found on the ground and cobweb spiders (Araneae: Theridiidae) build webs in the foliage. We present group-specific primers developed for five flea beetle species within the genus Phyllotreta and study the incidence of predation of flea beetles by these spider groups using DNA-based gut-content analysis. Wolf spiders of the genus Pardosa Koch and the cobweb spider, Phylloneta impressa (Koch), were collected in three winter OSR fields. Flea beetle densities as well as the occurrence of predators and alternative prey were monitored. In total 19.4% of the collected Pardosa tested positive for flea beetle DNA in the polymerase chain reaction analyses, whereas 10% P. impressa were positive. Pardosa were more likely to be positive for flea beetle DNA when Pardosa activity density was low. Phylloneta impressa were more likely to be positive for flea beetle DNA if they were positive for pollen beetle DNA. Implications of these results for conservation biological control and future studies of food webs in OSR are discussed.
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| 2. |
- An, Junghwa, et al.
(författare)
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Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009-30 November 2009
- 2010
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:2, s. 404-408
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Tidskriftsartikel (refereegranskat)abstract
- This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.
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| 3. |
- Björklund, Niklas, et al.
(författare)
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Mitochondrial DNA haplotypes indicate two postglacial re-colonization routes of the spruce bark beetle Ips typographus through northern Europe to Scandinavia
- 2014
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Ingår i: Journal of Zoological Systematics and Evolutionary Research. - : Hindawi Limited. - 0947-5745 .- 1439-0469. ; 52, s. 285-292
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Tidskriftsartikel (refereegranskat)abstract
- Species in northern Europe re-colonized the region after the last glacial maximum via several routes, which could have lingering signatures in current intraspecific trait variation. The spruce bark beetle, Ips typographus, occurs across Europe, and biological differences have been found between southern and northern Scandinavian populations. However, the postglacial history of I. typographus in Scandinavia has not been previously studied at a fine geographical scale. Therefore, we collected specimens across northern Europe and analysed the genetic variation in a quite large mitochondrial fragment (698 bp). A high genetic diversity was found in some of the most northern populations, in the Baltic States, Gotland and central Europe. Detected genetic and phylogeographic structures suggest that I. typographus re-colonized Scandinavia via two pathways, one from the northeast and one from the south. These findings are consistent with the re-colonization history of its host plant, Picea abies. However, we observed low haplotype and nucleotide diversity in southern Scandinavian populations of I. typographus, indicating that (unlike P. abies) it did not disperse across the Baltic Sea in multiple events. Further, the divergence among Scandinavian populations was shallow, conflicting with a scenario where I. typographus expanded concurrently with its host plant from a 'cryptic refugium' in the northwest.
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| 4. |
- Hambäck, Peter A., et al.
(författare)
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Bayesian species delimitation reveals generalist and specialist parasitic wasps on Galerucella beetles (Chrysomelidae) : sorting by herbivore or plant host
- 2013
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Ingår i: BMC Evolutionary Biology. - : BioMed Central. - 1471-2148. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: To understand the ecological and evolutionary consequences of species interactions in food webs necessitates that interactions are properly identified. Genetic analyses suggest that many supposedly generalist parasitoid species should rather be defined as multiple species with a more narrow diet, reducing the probability that such species may mediate indirect interactions such as apparent competition among hosts. Recent studies showed that the parasitoid Asecodes lucens mediate apparent competition between two hosts, Galerucella tenella and G. calmariensis, affecting both interaction strengths and evolutionary feedbacks. The same parasitoid was also recorded from other species in the genus Galerucella, suggesting that similar indirect effects may also occur for other species pairs. Methods: To explore the possibility of such interactions, we sequenced mitochondrial and nuclear genetic markers to resolve the phylogeny of both host and parasitoid and to test the number of parasitoid species involved. We thus collected 139 Galerucella larvae from 8 host plant species and sequenced 31 adult beetle and 108 parasitoid individuals. Results: The analysis of the Galerucella data, that also included sequences from previous studies, verified the five species previously documented as reciprocally monophyletic, but the Bayesian species delimitation for A. lucens suggested 3-4 cryptic taxa with a more specialised host use than previously suggested. The gene data analyzed under the multispecies coalescent model allowed us to reconstruct the species tree phylogeny for both host and parasitoid and we found a fully congruent coevolutionary pattern suggesting that parasitoid speciation followed upon host speciation. Conclusion: Using multilocus sequence data in a Bayesian species delimitation analysis we propose that hymenopteran parasitoids of the genus Asecodes that infest Galerucella larvae constitute at least three species with narrow diet breath. The evolution of parasitoid Asecodes and host Galerucella show a fully congruent coevolutionary pattern. This finding strengthens the hypothesis that the parasitoid in host search uses cues of the host rather than more general cues of both host and plant.
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| 5. |
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| 6. |
- Kanuch, Peter, et al.
(författare)
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Genetic diversity of a successful colonizer: isolated populations of Metrioptera roeselii regain variation at an unusually rapid rate
- 2014
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Ingår i: Ecology and Evolution. - : Wiley. - 2045-7758. ; 4, s. 1117-1126
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 7. |
- Kanuch, Peter, et al.
(författare)
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On variation of polyandry in a bush-cricket, Metrioptera roeselii, in northern Europe
- 2013
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Ingår i: Journal of Insect Science. - : Oxford University Press (OUP). - 1536-2442 .- 0970-3837. ; 13, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Patterns of polyandry in nuptial-gift-giving insects are often explained in terms of sexually antagonistic coevolution. However, the potential influence of environmental constraints and life- history traits on polyandry in these species is still largely unexplored. As an initial step in examining the role of these factors, this study measured the number of matings (spermatodoses per female) of female Roesel’s bush-crickets, Metrioptera roeselii Hagenbach (Orthoptera: Tettigoniidae), along a latitudinal gradient in northern Europe (16 sites, 53.89–60.47° N). Females contained between 0 and 5 spermatodoses (mean ± SE: 1.7 ± 0.08; N = 114), with the degree of polyandry generally increasing at higher latitudes (approximately 0.12–0.3 matings per degree of latitude). As expected, female body size also had an influence on polyandry; the number of matings increased from small to moderately large individuals before declining. The field-based results suggested that there were potentially interesting interactions between environment, life-history traits, and patterns of polyandry in nuptial-gift-giving insect species, and these potentially interesting interactions are used to outline future research directions.
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| 8. |
- Lundhagen, Anna, et al.
(författare)
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Colonization history of Metrioptera roeselii in northern Europe indicates human-mediated dispersal
- 2013
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 40, s. 977-987
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Tidskriftsartikel (refereegranskat)abstract
- AimThe 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. LocationFennoscandia, Baltic Sea coast, northern Europe. MethodsUsing a 676bp 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. ResultsBoth 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 >500km 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 conclusionsThe 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.
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| 9. |
- Lundhagen, Anna, et al.
(författare)
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Limited gene flow may enhance adaptation to local optima in isolated populations of the Roesel's bush cricket (Metrioptera roeselii)
- 2011
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Ingår i: Journal of Evolutionary Biology. - : Wiley. - 1010-061X .- 1420-9101. ; 24, s. 381-390
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 10. |
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