title: Abdominal color of the Asian citrus psyllid, Diaphorina citri, is associated with susceptibility to various insecticides.
abstract: BACKGROUND
  Color morphs of an insect species are known to vary in activities of detoxifying enzymes and associated susceptibility to insecticides. In Diaphorina citri, three color morphs are known to occur. In the present study, susceptibility to four insecticides was compared among gray/brown, blue/green and orange/yellow color morphs of field-collected D. citri.
  
  
  RESULTS
  The orange/yellow morph was significantly more susceptible to fenpropathrin than the blue/green morph, and imidacloprid and chlorpyrifos caused higher mortality in the orange/yellow morph than in the blue/green and gray/brown morphs. To confirm the genetic basis of variable levels of susceptibility, the relative expression of five CYP4 genes was compared among the color morphs. CYP4C67 was expressed at significantly higher levels in the blue/green than in the orange/yellow and gray/brown morphs. CYP4DA1, CYP4C68, CYP4G70 and CYP4DB1 were expressed at significantly higher levels in the blue/green and gray/brown morphs than in the orange/yellow morph. Lower expression of CYP4 genes in the orange/yellow morph as compared with the others was correlated with reduced signal of 45 kD cytochrome P450 proteins, as determined by the western blot.
  
  
  CONCLUSIONS
  The results indicate differential susceptibility of D. citri color morphs to insecticides, which will need to be accounted for in future insecticide monitoring programs and may affect management programs.
authors.affiliation: Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Tiwari
authors.forename: Nabil
authors.initials: N
authors.lastname: Killiny
authors.forename: Rajinder S
authors.initials: RS
authors.lastname: Mann
authors.forename: Erik J
authors.initials: EJ
authors.lastname: Wenninger
authors.forename: Lukasz L
authors.initials: LL
authors.lastname: Stelinski
mesh_terms: D000005:Abdomen; D000818:Animals; D015153:Blotting, Western; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D015870:Gene Expression; D006430:Hemiptera; D007305:Insecticide Resistance / Q000235:genetics*; D008297:Male; D010858:Pigmentation / Q000235:genetics*; D011110:Polymorphism, Genetic; D018675:Toxicity Tests
chemical_list: D003577:Cytochrome P-450 Enzyme System