title: Ecological Distribution and CQ11 Genetic Structure of Culex pipiens Complex (Diptera: Culicidae) in Italy.
abstract: Mosquitoes in the Culex pipiens complex are considered to be involved in the transmission of a range of pathogens, including West Nile virus (WNV). Although its taxonomic status is still debated, the complex includes species, both globally distributed or with a more limited distribution, morphologically similar and characterised by different physiological and behavioural traits, which affect their ability as vectors. In many European countries, Cx. pipiens and its sibling species Culex torrentium occur in sympatry, exhibiting similar bionomic and morphological characters, but only Cx. pipiens appears to play a vector role in WNV transmission. This species consists of two biotypes, pipiens and molestus, which can interbreed when in sympatry, and their hybrids can act as WNV-bridge vectors, due to intermediate ecological features. Considering the yearly WNV outbreaks since 2008 and given the morphological difficulties in recognising species and biotypes, our aim was to molecularly identify and characterised Cx. pipiens and Cx. torrentium in Italy, using recently developed molecular assays. Culex torrentium was not detected; as in other European countries, the pipiens and molestus biotypes were widely found in sympatry with hybrids in most environments. The UPGMA cluster analysis applied to CQ11 genotypic frequencies mainly revealed two groups of Cx. pipiens populations that differed in ecological features. The high propensity of the molestus biotype to exist in hypogean environments, where the habitat's physical characteristics hinder and preclude the gene flow, was shown. These results confirmed the CQ11 assay as a reliable diagnostic method, consistent with the ecological and physiological aspects of the populations analysed. Since the assessment of the actual role of three biotypes in the WNV circulation remains a crucial point to be elucidated, this extensive molecular screening of Cx. pipiens populations can provide new insights into the ecology of the species and may give useful indications to plan and implement WNV surveillance activities in Italy.
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Di Luca
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Luciano
authors.initials: L
authors.lastname: Toma
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Boccolini
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Severini
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: La Rosa
authors.affiliation: National Centre for Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Giada
authors.initials: G
authors.lastname: Minelli
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Gioia
authors.initials: G
authors.lastname: Bongiorno
authors.affiliation: Laboratory of Parasitology - Istituto Zooprofilattico Sperimentale delle Venezie, viale dell'Università 10, 35020, Legnaro, Padua, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Montarsi
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all'Adige, Trento, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Arnoldi
authors.affiliation: Laboratory of Parasitology - Istituto Zooprofilattico Sperimentale delle Venezie, viale dell'Università 10, 35020, Legnaro, Padua, Italy.
authors.forename: Gioia
authors.initials: G
authors.lastname: Capelli
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach 1, 38010, San Michele all'Adige, Trento, Italy.
authors.forename: Annapaola
authors.initials: A
authors.lastname: Rizzoli
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, viale Regina Elena, 299, 00161, Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Romi
mesh_terms: D000110:Acetylcholinesterase / Q000235:genetics; D063147:Animal Distribution; D000818:Animals; D006224:Cricetinae; D003465:Culex / Q000145:classification / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics; D005260:Female; D051456:Gene Flow; D017344:Genes, Insect; D056426:Genetic Loci; D005838:Genotype; D019476:Insect Proteins / Q000235:genetics; D007558:Italy; D008297:Male; D018895:Microsatellite Repeats; D058885:Multilocus Sequence Typing; D058974:Phylogeography
chemical_list: D019476:Insect Proteins; D003576:Electron Transport Complex IV; D000110:Acetylcholinesterase