title: Insecticide resistance status in the major West Nile virus vector Culex pipiens from Greece.
abstract: BACKGROUND
  One of the largest West Nile virus outbreaks in Europe occurred in Greece in 2010. Use of insecticides against Culex pipiens was substantially scaled up, as an emergency tool. Although mosquito control has been based on insecticides for several decades in Greece, insecticide resistance data are not available.
  
  
  RESULTS
  An examination was made of the resistance status of 13 Cx. pipiens populations from five regional units in Greece against four insecticides used for its control over a 3 year period. Bioassays demonstrated susceptibility of most populations to all insecticides, except for temephos in some regions, and deltamethrin and diflubenzuron on one occasion each. The authors also monitored the frequency of the pyrethroid target-site resistance mutations L1014F (kdr), as well as G119S and F290V in the Ace1 gene. Ace1 insensitivity mutations were found at low frequencies and always in heterozygocity. However, the frequency of kdr pyrethroid resistance mutations was higher (up to 63.0% in Thessaloniki).
  
  
  CONCLUSIONS
  The high frequency of kdr mutations indicates a risk that needs to be addressed, should the use of pyrethroids be further extended. There was no strong evidence of significant resistance levels against Bacillus thuringiensis var. israelensis and diflubenzuron. Continued monitoring of insecticide resistance is recommended for the application of appropriate management tactics.
authors.affiliation: Laboratory of Pesticide Science, Agricultural University of Athens, Athens, Greece.
authors.forename: Ilias
authors.initials: I
authors.lastname: Kioulos
authors.forename: Anastasia
authors.initials: A
authors.lastname: Kampouraki
authors.forename: Evangelia
authors.initials: E
authors.lastname: Morou
authors.forename: George
authors.initials: G
authors.lastname: Skavdis
authors.forename: John
authors.initials: J
authors.lastname: Vontas
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D003465:Culex / Q000235:genetics*; D004132:Diflubenzuron; D006115:Greece; D007303:Insect Vectors / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics; D007814:Larva; D009032:Mosquito Control; D009570:Nitriles; D011722:Pyrethrins; D000002:Temefos; D014902:West Nile virus
chemical_list: D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin; D004132:Diflubenzuron; D000002:Temefos
keywords: West Nile virus; detoxification; diagnostics; mosquito control; resistance