title: Diagnostic assays based on esterase-mediated resistance mechanisms in western corn rootworms (Coleoptera: Chrysomelidae).
abstract: Resistance to methyl-parathion among Nebraska western corn rootworm, Diabrotica virgifera virgifera LeConte, populations is associated with increased hydrolytic metabolism of an organophosphate insecticide substrate. An electrophoretic method to identify resistant individuals based on the staining intensity of esterase isozymes on nondenaturing polyacrylamide gels was developed. Three groups of esterases (I, II, and III) were visible on the gels, but only group II esterase isozymes were intensified in resistant populations. A total of 26 and 31 field populations of western corn rootworms from Nebraska (in 1998 and 1999, respectively) were assessed with nondenaturing polyacrylamide gel electrophoresis (PAGE) assays and diagnostic concentration bioassays. Significant correlations were observed between the two diagnostic assays. Group II esterase isozymes provide a reliable biochemical marker for detection of methyl-parathion resistance in individual western corn rootworms and a tool for monitoring the frequency of resistant individuals in field populations.
authors.affiliation: Department of Entomology, University of Nebraska, Lincoln, NE 68583-0816, USA.
authors.forename: Xuguo
authors.initials: X
authors.lastname: Zhou
authors.forename: Michael E
authors.initials: ME
authors.lastname: Scharf
authors.forename: Srinivas
authors.initials: S
authors.lastname: Parimi
authors.forename: Lance J
authors.initials: LJ
authors.lastname: Meinke
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Wright
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Chandler
authors.forename: Blair D
authors.initials: BD
authors.lastname: Siegfried
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D004950:Esterases / Q000032:analysis*; D007305:Insecticide Resistance / Q000502:physiology*; D007306:Insecticides; D007527:Isoenzymes / Q000032:analysis*; D008743:Methyl Parathion
chemical_list: D007306:Insecticides; D007527:Isoenzymes; D008743:Methyl Parathion; D004950:Esterases