title: Dynamics of esterase alleles in Culex pipiens complex mosquitoes in Beijing.
abstract: To investigate insecticide resistance levels and dynamic changes of carboxylesterase polymorphism with time in resistant populations of mosquitoes in the Culex pipiens complex, four field populations were collected in September 2006. The resistance levels of fourth-instar larvae to organophosphate (dichlorvos, parathion, and chlorpyrifos), carbamate (fenobucarb and propoxur), and pyrethroid (permethrin and tetramethrin) insecticides were determined by bioassay. Larvae had a low but significant resistance to organophosphate and carbamate insecticides but no significant resistance to pyrethroid insecticides. Starch gel electrophoresis revealed the presence of the overproduced esterases B1, A2-B2, A8-B8, A9-B9, and All-B11. The frequency of each overproduced esterases varied depending on its regional localities. Compared with previous surveys, the polymorphism of amplified esterase alleles in Beijing populations increased, although the resistance level to organophosphate insecticides declined.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insect & Rodents, Institute of Zoology, Chinese Academy of Science, Da Tun Lu, Chao Yang Qu, Beijing 100101, China.
authors.forename: Shuaiguo
authors.initials: S
authors.lastname: Yan
authors.forename: Zhonghua
authors.initials: Z
authors.lastname: Wu
authors.forename: Feng
authors.initials: F
authors.lastname: Cui
authors.forename: Qiao
authors.initials: Q
authors.lastname: Zhao
authors.forename: Chuanling
authors.initials: C
authors.lastname: Qiao
mesh_terms: D000483:Alleles; D000818:Animals; D002681:China; D003465:Culex / Q000187:drug effects / Q000235:genetics*; D004950:Esterases / Q000235:genetics*; D019143:Evolution, Molecular; D005838:Genotype; D019476:Insect Proteins / Q000235:genetics*; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D007814:Larva / Q000187:drug effects / Q000235:genetics; D011110:Polymorphism, Genetic
chemical_list: D019476:Insect Proteins; D007306:Insecticides; D004950:Esterases