title: Thiamethoxam acts as a target-site synergist of spinosad in resistant strains of Frankliniella occidentalis.
abstract: BACKGROUND
  Previous studies have suggested that the resistance mechanism towards spinosad in Frankliniella occidentalis (Pergande) is an altered target site. Like the neonicotinoids, the spinosyns act on nicotinic acetylcholine receptors (nAChRs) in insects, but at a distinct site. The changes in nAChRs related to spinosad resistance in thrips might involve interaction with neonicotinoids. In this study, the efficacy of spinosad and neonicotinoids, alone and in combination, was evaluated in susceptible and spinosad-resistant thrips strains.
  
  
  RESULTS
  The neonicotinoids tested were imidacloprid, thiacloprid, acetamiprid, thiamethoxam and clothianidin. No cross-resistance was shown between spinosad and any of the neonicotinoids. However, an increased toxicity was observed when a mixture of spinosad with thiamethoxam or clothianidin was tested. No synergism was found in the susceptible strains. The more spinosad-resistant the thrips strain, the stronger was the synergism.
  
  
  CONCLUSIONS
  Data suggest that spinosad and thiamethoxam may interact at the nAChRs in spinosad-resistant thrips, facilitating enhanced insecticidal action.
authors: Departamento de Producción Vegetal, Universidad Politécnica de Cartagena, Cartagena, Spain.
authors: Juan
authors: J
authors: Guillén
authors: Pablo
authors: P
authors: Bielza
mesh_terms: D000818:Animals; D004338:Drug Combinations; D004357:Drug Synergism; D019476:Insect Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D007305:Insecticide Resistance; D007306:Insecticides / Q000494:pharmacology*; D018942:Macrolides / Q000494:pharmacology*; D000073943:Neonicotinoids; D018733:Nicotinic Antagonists / Q000494:pharmacology; D009574:Nitro Compounds / Q000494:pharmacology*; D010078:Oxazines / Q000494:pharmacology*; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism; D000077922:Thiamethoxam; D013844:Thiazoles / Q000494:pharmacology*; D061149:Thysanoptera / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism
chemical_list: D004338:Drug Combinations; D019476:Insect Proteins; D007306:Insecticides; D018942:Macrolides; D000073943:Neonicotinoids; D018733:Nicotinic Antagonists; D009574:Nitro Compounds; D010078:Oxazines; D011978:Receptors, Nicotinic; D013844:Thiazoles; D000077922:Thiamethoxam; C415329:spinosad