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Hesson J.C.,Uppsala University | LundstroM J.O.,Uppsala University | LundstroM J.O.,Nedre Dalalvens Utvecklings AB | Halvarsson P.,Uppsala University | And 2 more authors.
Medical and Veterinary Entomology

Culex pipiens pipiens Linnaeus and Culex torrentium Martini (Diptera: Culicidae) are closely related vector species that exist sympatrically in Europe. The two species are morphologically almost identical and can only be distinguished with certainty by characters of the male genitalia. Hence, correct species identification and conclusions on distribution and vector status are very difficult and often neglected. Therefore, we developed a reliable and simple mitochondrial cytochrome c oxidase subunit I (COI) gene restriction enzyme assay to discriminate between Cx. pipiens and Cx. torrentium, based on the analysis of morphologically identified male specimens. We sequenced approximately 830 bp in the 3′ region of the mitochondrial COI gene of 18 morphologically identified males of Cx. pipiens and Cx. torrentium. Two restriction enzymes (FspBI and SspI) that could distinguish between the two species according to species-specific differences in these sequences were chosen. The restriction enzymes were tested on 227 samples from Sweden and verified by sequencing 44 of them. The enzyme FspBI correctly identified all investigated samples; the enzyme SspI identified all samples except one Cx. torrentium. We hope the method and the findings presented here will help to shed light on the true distribution and relative proportions of the two species in Europe. © 2010 The Authors. Journal compilation © 2010 The Royal Entomological Society. Source

Chapgier M.-A.,Agence Regionale de ta Sante | Foussadier R.,Entente Interdepartementale Rhone Alpes pour la Demoustication
Techniques - Sciences - Methodes

With the expansion of transports, the range of many species of animals and plants alike is constantly changing. Mosquitoes are no exception to the rule. The arrival in France of one of them [Aedes albopictus or tiger mosquito) is the continuation of a process which begun many decades ago allowing this species from south-east Asia to colonize five continents. To prevent the Aedes albopictus from spreading, a species capable of transmitting various arboviruses, government measures have been implemented since 2006. This is the program against the spread of chikungunya and dengue. The breeding sites of Aedes albopictus are largely produced by humans and are in private housings (vases, saucers, yards, gardens, or gutters⋯). Similarly, the way we use our urban infrastructure (roof terrace, rainwater drains⋯) contributes to the settlement of the mosquito. The most effective and radical way to protect ourselves from these nuisances of this species is to physically remove them, or limit their creation by taking into account the risks associated with this species within the rules of construction and town planning. Source

Minard G.,University Claude Bernard Lyon 1 | Tran F.H.,University Claude Bernard Lyon 1 | Van V.T.,University Claude Bernard Lyon 1 | Goubert C.,CNRS Biometry and Evolutionary Biology Laboratory | And 7 more authors.
Frontiers in Microbiology

The Asian tiger mosquito Aedes albopictus is one of the most significant pathogen vectors of the twenty-first century. Originating from Asia, it has invaded a wide range of eco-climatic regions worldwide. The insect-associated microbiota is now recognized to play a significant role in host biology. While genetic diversity bottlenecks are known to result from biological invasions, the resulting shifts in host-associated microbiota diversity has not been thoroughly investigated. To address this subject, we compared four autochthonous Ae. albopictus populations in Vietnam, the native area of Ae. albopictus, and three populations recently introduced to Metropolitan France, with the aim of documenting whether these populations display differences in host genotype and bacterial microbiota. Population-level genetic diversity (microsatellite markers and COI haplotype) and bacterial diversity (16S rDNA metabarcoding) were compared between field-caught mosquitoes. Bacterial microbiota from the whole insect bodies were largely dominated by Wolbachia pipientis. Targeted analysis of the gut microbiota revealed a greater bacterial diversity in which a fraction was common between French and Vietnamese populations. The genus Dysgonomonas was the most prevalent and abundant across all studied populations. Overall genetic diversities of both hosts and bacterial microbiota were significantly reduced in recently established populations of France compared to the autochthonous populations of Vietnam. These results open up many important avenues of investigation in order to link the process of geographical invasion to shifts in commensal and symbiotic microbiome communities, as such shifts may have dramatic impacts on the biology and/or vector competence of invading hematophagous insects. © 2015 Minard, Tran, Van, Goubert, Bellet, Lambert, Kim, Thuy, Mavingui and Valiente Moro. Source

Hesson J.C.,Uppsala University | Rettich F.,National Institute of Public Health | Merdic E.,Josip Juraj Strossmayer University of Osijek | Vignjevic G.,Josip Juraj Strossmayer University of Osijek | And 10 more authors.
Medical and Veterinary Entomology

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. © 2013 The Royal Entomological Society. Source

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