title: Insecticide resistance of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in mainland China.
abstract: BACKGROUND
  In order to investigate the extent of resistance of oriental fruit fly, Bactrocera dorsalis (Hendel), which is a widespread pest throughout tropical, subtropical and temperate fruit crops, 25 populations of this insect were collected from 13 sites in mainland China in 2007 and 2008. In addition, resistant strains were established that showed increasing development of resistance.
  
  
  RESULTS
  Compared with the susceptible strain, one population of B. dorsalis expressed high resistance (RR = 70.4-fold), 16 populations expressed medium resistance (11.5-fold < RR < 25.8-fold) and eight populations had low resistance or remained susceptible (1.4-fold < RR < 8.9-fold) to trichlorphon. As regards β-cypermethrin, one population showed high resistance (RR = 44.0-fold), nine populations expressed medium resistance (12.2-fold < RR < 28.4-fold), 14 populations expressed low or minor resistance (3.0-fold < RR < 9.7-fold) and one population remained susceptible (RR = 1.1-fold). As regards avermectin, five populations had developed high resistance (44.3-fold < RR < 104-fold), seven populations expressed medium resistance (11.4-fold < RR < 38.6-fold) and three populations expressed low or minor resistance (3.5-fold < RR < 5.6-fold). A continuous resistance selection in the laboratory strain showed that the resistance ratios to trichlorphon, β-cypermethrin and avermectin were 71.6-fold, 333-fold and 70.4-fold respectively.
  
  
  CONCLUSIONS
  The data provided a comprehensive survey of insecticide resistance in Bactrocera dorsalis in mainland China. All results suggested that early resistance management programmes should be established for restoring the efficacy of pesticide-based control measures.
authors.affiliation: Laboratory of Insect Ecology, College of Natural Resources and Environment, South China Agricultural University, Guangzhou, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Jin
authors.forename: Ling
authors.initials: L
authors.lastname: Zeng
authors.forename: Yuying
authors.initials: Y
authors.lastname: Lin
authors.forename: Yongyue
authors.initials: Y
authors.lastname: Lu
authors.forename: Guangwen
authors.initials: G
authors.lastname: Liang
mesh_terms: D000818:Animals; D002681:China; D005838:Genotype; D007300:Insect Control; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology; D007559:Ivermectin / Q000031:analogs & derivatives / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology; D033621:Tephritidae / Q000187:drug effects* / Q000235:genetics; D014236:Trichlorfon / Q000494:pharmacology
chemical_list: D007306:Insecticides; D011722:Pyrethrins; C017160:cypermethrin; D007559:Ivermectin; C019264:avermectin; D014236:Trichlorfon