title: Insecticide resistance traits differ among and within host races in Aphis gossypii.
abstract: BACKGROUND
  The polyphagous cotton-melon aphid Aphis gossypii Glover is structured into geographically widespread host races comprising a few clones specialised on Cucurbitaceae, cotton, eggplant or pepper. To assess insecticide resistance among and within host races, leaf disc bioassays were conducted on aphid clones collected from Cucurbitaceae (genotypes C4 and C9), cotton (genotypes Burk and Ivo), eggplant (genotype Auber) and pepper (genotype PsP4). Molecular diagnostic (PCR-RFLP) and enzyme assays were also performed to detect the basic mechanisms underlying insecticide resistance.
  
  
  RESULTS
  All six clones were susceptible to acetamiprid (neonicotinoid) or carbosulfan (carbamate). Conversely, all clones were resistant to dimethoate (organophosphate) (RF = 4.1-38.1) and carried mutation S431F in the acetylcholinesterase gene. Auber, PsP4 and Burk also carried mutation A302S in this gene, which possibly conferred moderate resistance (RF = 3.7-6.8) to profenofos and monocrotophos (organophosphates). Auber and Burk were highly resistant (RF = 41.2 and 473 respectively) to cypermethrin (pyrethroid). This resistance was likely associated with point mutation super-kdr (M918L) in the voltage-gated sodium channel gene (para gene) or metabolic detoxification mediated by esterase and oxidase enzymes.
  
  
  CONCLUSIONS
  Multiple resistance to a broad range of insecticides and multiple mechanisms of resistance in some clones could explain to some extent the low genetic diversity observed within A. gossypii host races.
authors.affiliation: INRA, UMR 1301 Interactions Biotiques et Santé Végétale, Sophia Antipolis, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Carletto
authors.forename: Thibaud
authors.initials: T
authors.lastname: Martin
authors.forename: Flavie
authors.initials: F
authors.lastname: Vanlerberghe-Masutti
authors.forename: Thierry
authors.initials: T
authors.lastname: Brévault
mesh_terms: D000818:Animals; D001042:Aphids / Q000145:classification* / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D001681:Biological Assay; D004357:Drug Synergism; D014644:Genetic Variation; D007305:Insecticide Resistance / Q000187:drug effects / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology*; D018515:Plant Leaves; D010944:Plants; D017354:Point Mutation; D013045:Species Specificity
chemical_list: D007306:Insecticides