title: Biotype and insecticide resistance status of the whitefly Bemisia tabaci from China.
abstract: BACKGROUND
  Resistance to numerous insecticide classes in Bemisia tabaci Gennadius has impaired field control efficacy in south-eastern China. The biotype and resistance status of B. tabaci collected from these areas was investigated.
  
  
  RESULTS
  Two different biotypes of B. tabaci (B-biotype and Q-biotype) were detected in south-eastern China, and the samples collected from geographical regions showed a prevalence of the Q-biotype and the coexistence of B- and Q-biotypes in some regions. Moderate to high levels of resistance to two neonicotinoids were established in both biotypes (28-1900-fold to imidacloprid, 29-1200-fold to thiamethoxam). Medium to high levels of resistance to alpha-cypermethrin (22-610-fold) were also detected in both biotypes. Four out of 12 populations had low to medium levels of resistance to fipronil (10-25-fold). Four out of 12 populations showed low levels of resistance to spinosad (5.7-6.4-fold). All populations tested were susceptible to abamectin.
  
  
  CONCLUSIONS
  The Q-biotype B. tabaci is supplanting the B-biotype which used to be ubiquitous in China. Field populations of both B- and Q-biotypes of B. tabaci have developed high levels of resistance to imidacloprid and thiamethoxam. Abamectin is the most effective insecticide against adult B. tabaci from all populations.
authors.affiliation: College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects (Ministry of Agriculture of China), Nanjing 210095, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Wang
authors.forename: Haifei
authors.initials: H
authors.lastname: Yan
authors.forename: Yihua
authors.initials: Y
authors.lastname: Yang
authors.forename: Yidong
authors.initials: Y
authors.lastname: Wu
mesh_terms: D000818:Animals; D002681:China; D003576:Electron Transport Complex IV / Q000235:genetics; D006430:Hemiptera / Q000145:classification* / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D007093:Imidazoles / Q000494:pharmacology; D007300:Insect Control; D019476:Insect Proteins / Q000235:genetics; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology; D007559:Ivermectin / Q000031:analogs & derivatives; D008969:Molecular Sequence Data; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000494:pharmacology; D010802:Phylogeny; D010944:Plants / Q000469:parasitology; D011722:Pyrethrins / Q000494:pharmacology
chemical_list: D007093:Imidazoles; D019476:Insect Proteins; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D011722:Pyrethrins; C017160:cypermethrin; C082359:imidacloprid; C048324:abamectin; D007559:Ivermectin; D003576:Electron Transport Complex IV