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| 2. |
- Hesson, Jenny C., 1980-, et al.
(författare)
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The arbovirus vector Culex torrentium is more prevalent than Culex pipiens in northern and central Europe
- 2014
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Ingår i: Medical and Veterinary Entomology. - : Wiley. - 0269-283X .- 1365-2915. ; 28:2, s. 179-186
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Tidskriftsartikel (refereegranskat)abstract
- Two species of arbovirus vector, Culex torrentium and Culex pipiens (Diptera: Culicidae), occur in several European countries, but difficulties in their accurate identification and discrimination have hampered both detailed and large-scale distribution and abundance studies. Using a molecular identification method, we identified to species 2559 larvae of Cx. pipiens/torrentium collected from 138 sites in 13 European countries ranging from Scandinavia to the Mediterranean coast. In addition, samples of 1712 males of Cx. pipiens/torrentium collected at several sites in the Czech Republic were identified to species based on the morphology of their hypopygia. We found that the two species occur together in large areas of Europe, and that Cx. torrentium dominates in northern Europe and Cx. pipiens dominates south of the Alps. The transition in dominance occurs in central Europe, where both species are roughly equally common. There was a strong correlation between the length of the growing season at different sites and occurrences of the two species. As the growing season increases, the proportion and detection of Cx. torrentium decrease, whereas those of Cx. pipiens increase. The present findings have important consequences for the interpretation of the results of studies on major enzootic and link-vectors of mosquito-borne bird-associated viruses (i.e. Sindbis, West Nile and Usutu viruses), especially in central Europe and Scandinavia.
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| 3. |
- Lundström, Jan O., et al.
(författare)
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Production of wetland Chironomidae (Diptera) and the effects of using Bacillus thuringiensis israelensis for mosquito control
- 2010
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Ingår i: Bulletin of entomological research. - Cambridge : Cambridge University Press. - 0007-4853 .- 1475-2670. ; 100:1, s. 117-125
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Tidskriftsartikel (refereegranskat)abstract
- Massive mosquito nuisance problems, caused by the flood-water mosquito Aedes sticticus, occur after floods in the flood plains of the River Dalalven, central Sweden. Since 2002, the biological mosquito larvicide Bacillus thuringiensis var. israelensis (Bti) has been used to control these mosquitoes. Here, we report results from the first six years of monitoring Chironomidae, the most Susceptible non-target organisms, in three wetlands with Bti-treatment against mosquitoes and in three wetlands without treatment. Emergence traps were used for continuous insect sampling from May to September each year, 2002-2007, and were emptied once a week. A total of 21,394 chironomids of 135 species were collected, and the Subfamily Orthocladiinae dominated the fauna followed by Chironominae and Tanypodinae. The annual chironomid production in the wetlands was low, with ail average of 1.91.7 individuals per m(2) and 42 g ash-free dry weight per m(2) We found no reduced production of chironomids at neither family, nor subfamily level, in Bti-treated as compared to untreated wetlands. This is the first long-term follow-up study of the possible effects of Bti-based mosquito larval control oil chironomid species production. In the short-term view, one species had higher production in treated areas. In the long-term view, four species had higher and one species had lower production in treated areas. We conclude that the B3ti-based control of floodwater mosquitoes does not cause and, major direct negative effects on chironomid production, and therefore does not seem to induce any risk for indirect negative effects on birds, bats or any other predators feeding on chironomids.
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| 4. |
- Prokofiev, A, et al.
(författare)
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A New Neutron Facility for Single-Event Effect Testing
- 2004
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Ingår i: Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application. ; , s. 160-162
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 5. |
- Schäfer, Martina, et al.
(författare)
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Influence of landscape structure on mosquitoes (Diptera : Culicidae) and dytiscids (Coleoptera
- 2006
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Ingår i: Wetlands (Wilmington, N.C.). - 0277-5212 .- 1943-6246. ; 26:1, s. 57-68
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Patterns of species diversity and community structure depend on scales larger than just a single habitat and might be influenced by the surrounding landscape. We studied the response of two insect families, mosquitoes (Diptera: Culicidae) and dytiscids (Coleoptera: Dytiscidae), to landscape variables at five spatial scales. We studied adult mosquito and dytiscid abundance, diversity, and species assemblages in relation to water permanence (area of permanent water bodies versus temporary wetlands) and forest cover (area covered by forest versus open land) within nested circles of 100 to 3000 m around trap sites in four wetlands in southern Sweden and in five wetlands in central Sweden. We found that mosquito abundance was greatest in areas with plentiful forest cover and a high proportion of temporary water, while most dytiscids favored open areas with a high proportion of permanent wetlands. However, diversity of both mosquitoes and dytiscids was positively correlated with high permanence and little forest cover. Mosquito species assemblages were mainly influenced by forest cover at a large spatial scale, whereas permanence was more important at local scales. Dytiscid species assemblages were mainly influenced by water permanence, especially at intermediate spatial scales. These results can be explained by the flight capability and dispersal behavior of mosquito and dytiscid species. The observed landscape associations of mosquitoes and dytiscids could be useful when creating new wetlands. Mosquito colonization could be reduced by creating permanent wetlands in an open landscape, which would favor colonization by dytiscids, a potential predator of mosquito larvae, while also supporting the diversity of both taxa.
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| 6. |
- Schäfer, Martina L., et al.
(författare)
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Influence of landscape structures on mosquitoes (Diptera: Culicidae) and dytiscid (Coleoptera: Dytiscidae) at five spatial scales in Swedish wetlands
- 2006
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Ingår i: Wetlands (Wilmington, N.C.). - 0277-5212 .- 1943-6246. ; 26:1, s. 57-68
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Tidskriftsartikel (refereegranskat)abstract
- Patterns of species diversity and community structure depend on scales larger than just a single habitat and might be influenced by the surrounding landscape. We studied the response of two insect families, mosquitoes (Diptera: Culicidae) and dytiscids (Coleoptera: Dytiscidae), to landscape variables at five spatial scales. We studied adult mosquito and dytiscid abundance, diversity, and species assemblages in relation to water permanence (area of permanent water bodies versus temporary wetlands) and forest cover (area covered by forest versus open land) within nested circles of 100 to 3000 m around trap sites in four wetlands in southern Sweden and in five wetlands in central Sweden. We found that mosquito abundance was greatest in areas with plentiful forest cover and a high proportion of temporary water, while most dytiscids favored open areas with a high proportion of permanent wetlands. However, diversity of both mosquitoes and dytiscids was positively correlated with high permanence and little forest cover. Mosquito species assemblages were mainly influenced by forest cover at a large spatial scale, whereas permanence was more important at local scales. Dytiscid species assemblages were mainly influenced by water permanence, especially at intermediate spatial scales. These results can be explained by the flight capability and dispersal behavior of mosquito and dytiscid species. The observed landscape associations of mosquitoes and dytiscids could be useful when creating new wetlands. Mosquito colonization could be reduced by creating permanent wetlands in an open landscape, which would favor colonization by dytiscids, a potential predator of mosquito larvae, while also supporting the diversity of both taxa.
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| 7. |
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| 8. |
- Vinnersten, Thomas Z. Persson, et al.
(författare)
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Diving beetle assemblages of flooded wetlands in relation to time, wetland type and Bti-based mosquito control
- 2009
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Ingår i: Hydrobiologia. - : Springer Science and Business Media LLC. - 0018-8158 .- 1573-5117. ; 635:1, s. 189-203
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Tidskriftsartikel (refereegranskat)abstract
- We investigated the abundance and taxonomic composition of the aquatic predatory insect fauna, with focus on adult diving beetles (Coleoptera: Dytiscidae), in eight temporary flooded wet meadows and two alder swamps in the River Dalalven flood-plains, central Sweden from 2002 to 2006. Diving beetles are generalist predators and often abundant in various waters, including temporary wetlands. In the River Dalalven floodplains, recurrent floods induce massive hatching of flood-water mosquitoes (Diptera: Culicidae), which constitute a superabundant patchy and irregular food resource for aquatic predatory insects. Our aims were (1) to characterize the assemblage of adult diving beetles occurring in the wetlands during floods in relation to time and wetland type and (2) to evaluate the effect on the aquatic predator assemblage of strongly reducing the abundance of a potential prey, flood-water mosquito larvae with Bacillus thuringiensis var. israelensis (Bti) during floods. We found diving beetles to be the dominating aquatic predatory insect taxa in all 10 wetlands. There was a difference in Dytiscidae species richness but not in diversity between wet meadows and alder swamps after rarefaction. The cluster analysis based on dytiscid species and abundances showed very high similarities between the wetlands. The variance component analysis was unable to distinguish any factor that could explain more than 7.4% of the variation in the dytiscid species assemblages. The only effect of Bti-treatment against flood-water mosquito larvae, potential food for the predatory dytiscids, was a slight increase in abundance of the medium-sized dytiscid species. Our results are in accordance with previous studies, suggesting that irregular and recurrent flood dynamic structure the dytiscid fauna more than food limitations and environmental factors.
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| 9. |
- Blomgren, Eric, et al.
(författare)
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Pest occurrence of Aedes rossicus close to the Arctic Circle in northern Sweden
- 2018
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Ingår i: Journal of Vector Ecology. - : Society for Vector Ecology. - 1081-1710 .- 1948-7134. ; 43:1, s. 36-43
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Tidskriftsartikel (refereegranskat)abstract
- Major nuisance species are found among the floodwater mosquitoes and snow-pool mosquitoes, with the former being the main reason for mosquito control in most areas. Nuisance species vary with the area, and previous reports from northern areas conclude that the nuisance is most often caused by snow-pool mosquitoes. We investigated the mosquito fauna and abundances of host-seeking females using CDC traps baited with carbon dioxide, in overtornea city near the Arctic Circle in northern Sweden, after earlier complaints about massive mosquito nuisance. The abundance of host-seeking female mosquitoes was high in 2014, with a maximum of similar to 15,400 individuals per CDC trap night, of which 89% was the floodwater mosquito Aedes rossicus. Surprisingly, the main nuisance species was a floodwater mosquito, occurring at the northernmost location it has ever been recorded in Sweden. Our report is probably the first documentation of such large numbers of Aedes rossicus in any locality and probably the first documentation of a severe floodwater mosquito nuisance near the Arctic Circle. Given the historical data on river discharge in the area, the nuisance is recurrent. We conclude that in northern localities, as well as in more southern localities, production of floodwater mosquitoes is a natural component of the floodplain fauna of rivers with a fluctuating water flow regime. Also, the floodwater mosquitoes Aedes sticticus and Aedes vexans were found north of their formerly known distribution in Sweden.
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| 10. |
- Brodin, Yngve, et al.
(författare)
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Tavastia yggdrasilia, a new orthoclad midge (Diptera: Chironomidae) from Europe
- 2008
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Ingår i: Aquatic Insects. - : Informa UK Limited. - 0165-0424 .- 1744-4152. ; 30:4, s. 261-267
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Tidskriftsartikel (refereegranskat)abstract
- A new species of the chironomid genus Tavastia was frequently collected in wetlands of the River Dalalven lowlands in central Sweden from 2002 to 2007. Unpublished data revealed that the species has been known from Finland since 1974. The new species T. yggdrasilia can be separated from other Tavastia species by the combination of a gonostylus with strong crista dorsalis in proximal half, AR 0.93-1.16, and wing veins M3+4 and Cu1 without setae. A description of the male and the female is included, as is also a key to the males of the four known species of Tavastia. All records of T. yggdrasilia are from sites with mesotrophic or eutrophic conditions.
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