title: Multiple resistance and biochemical mechanisms of pyridaben resistance in Tetranychus urticae (Acari: Tetranychidae).
abstract: A field colony of Tetranychus urticae (Koch) (Acari: Tetranychidae) resistant to pyridaben was selected with pyridaben successively for 20 generations to produce the PR-20 strain. Resistance and multiple resistance levels of the PR-20 strain to 15 acaricides were determined using a spray bioassay. The PR-20 strain was extremely resistant to pyridaben (resistance ratio [RR] = 240]. The strain exhibited extremely strong resistance to fenpyroximate (RR=373) and acrinathrin (RR=329) and strong resistance to benzoximate (RR=84). An RR = 10-40 was observed with abamectin, fenazaquin, fenbutatin oxide, fenpropathrin, and tebufenpyrad. The PR-20 strain showed low levels of resistance (RR <10) to azocyclotin, bromopropylate, chlorfenapyr, dicofol, milbemectin, and propargite. Synergist experiments with different metabolic inhibitors revealed that piperonyl butoxide (PBO), a mixed function oxidase (MFO) inhibitor, had the greatest effect on pyridaben resistance. PBO significantly caused pyridaben resistance in the PR-20 strain to drop to the full susceptibility level of the susceptible (S) strain. However, there was no significant difference in MFO activities measured using a model substrate between the S and PR-20 strains. These results suggest that use of certain acaricides with little multiple resistance or PBO will be useful for the management of pyridaben resistance in the field.
authors.affiliation: School of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hyung-Man
authors.initials: HM
authors.lastname: Park
authors.forename: Jum-Rae
authors.initials: JR
authors.lastname: Cho
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Ahn
mesh_terms: D000818:Animals; D018432:Drug Resistance, Multiple; D007305:Insecticide Resistance / Q000502:physiology*; D010574:Pesticide Synergists; D010575:Pesticides / Q000494:pharmacology*; D011724:Pyridazines / Q000494:pharmacology*; D040102:Tetranychidae / Q000187:drug effects* / Q000201:enzymology / Q000502:physiology*
chemical_list: D010574:Pesticide Synergists; D010575:Pesticides; D011724:Pyridazines; C428725:pyridaben