title: Spatial distribution and esterase activity in populations of Aedes (Stegomyia) aegypti (Linnaeus) (Diptera: Culicidae) resistant to temephos.
abstract: BACKGROUND
  The need for studies that describe the resistance patterns in populations of Aedes aegypti (Linnaeus) in function of their region of origin justified this research, which aimed to characterize the resistance to temephos and to obtain information on esterase activity in populations of Aedes aegypti collected in municipalities of the State of Paraíba.
  
  
  METHODS
  Resistance to temephos was evaluated and characterized from the diagnostic dose of 0.352mg i.a./L and multiple concentrations that caused mortalities between 5% and 99%. Electrophoresis of isoenzymes was used to verify the patterns of esterase activity among populations of the vector.
  
  
  RESULTS
  All populations of Aedes aegypti were resistant to temephos, presenting a resistance rate (RR) greater than 20. The greatest lethal dose 50% of the sample (CL50) was found for the municipality of Lagoa Seca, approximately forty-one times the value of CL50 for the Rockefeller population. The populations characterized as resistant showed two to six regions of α and β-esterase, called EST-1 to EST-6, while the susceptible population was only seen in one region of activity.
  
  
  CONCLUSIONS
  Aedes aegypti is widely distributed and shows a high degree of resistance to temephos in all municipalities studied. In all cases, esterases are involved in the metabolism and, consequently, in the resistance to temephos.
authors.affiliation: Laboratório de Entomologia, Núcleo de Sistemática e Bioecologia de Insetos, Departamento de Biologia, Universidade Estadual da Paraíba, Campina Grande, PB, Brasil. nessynhaporto@gmail.com
authors.forename: Wanessa Porto Tito
authors.initials: WP
authors.lastname: Gambarra
authors.forename: Walter Fabrício Silva
authors.initials: WF
authors.lastname: Martins
authors.forename: Maurício Lilioso
authors.initials: ML
authors.lastname: de Lucena Filho
authors.forename: Ingredy Meneses Cavalcanti
authors.initials: IM
authors.lastname: de Albuquerque
authors.forename: Otávia Karla os Santos
authors.initials: OK
authors.lastname: Apolinário
authors.forename: Eduardo Barbosa
authors.initials: EB
authors.lastname: Beserra
mesh_terms: D000330:Aedes / Q000201:enzymology*; D000818:Animals; D004586:Electrophoresis; D004950:Esterases / Q000378:metabolism*; D007305:Insecticide Resistance; D007306:Insecticides; D007928:Lethal Dose 50; D000002:Temefos
chemical_list: D007306:Insecticides; D004950:Esterases; D000002:Temefos