The 2005 ESA Annual Meeting and Exhibition
December 15-18, 2005
Ft. Lauderdale, FL

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Friday, December 16, 2005

Cross-resistance and biochemical mechanisms of pyridaben resistance to Tetranychus urticae Koch

Byeong-Ryeol Choi, brchoi@rda.go.kr1, Si-Woo Lee, siwlee@rda.go.kr1, Hyung-Man Park, hmpark@rda.go.kr1, Deok-Ho Kwon, jota486@hanmail.net2, and Si-Hyeock Lee, (1) Applied Entomology Division, National Institute of Agricultural Science and Technology, 249 Seodundong, Suwon, South Korea, (2) Seoul National University, Entomology program School of Agricultural Biotechnology, College of Agriculture and Life Sciences, San 56-1, Shillim-dong, Gwanak-gu, Seoul, South Korea


Two-spotted spider mite, Tetranychus urticae Koch, is most economically important pest on crops in Korea. Control of spider mite populations is primarily dependent upon the acaricides. Pyridaben, belongs to METI (mitochondrial electron transport inhibitor) group, was first registered in Korea in 1992. Field populations of T. urticae collected from apple trees and strawberries appeared to be highly resistant to pyridaben in spite of its short-term use. A strain of pyridaben resistant T. urticae collected from apple orchard in 2002 was further selected with pyridaben 20% WP for 27 generations at a selection pressure of 30-50% mortality (PR-27 strain). Resistance and cross-resistance levels of the PR-27 strain to 16 acaricides were determined by a spray method. The PR-27 strain was extremely resistant to pyridaben (Resistance ratio(RR) 86). The strain exhibited positive cross-resistance to fenpyroximate (RR >12), fenazaquin (RR >7.8) and tebufenpyrad(RR >8.7). The PR-27 strain showed low levels of cross-resistance to fenpropathrin, abamectin, monocrotophos, dicofol, chlorfenapyr, azocyclotin and fenbutatin oxide. Synergist experiments with different metabolic inhibitors revealed that piperonyl butoxide(PBO) had the low effect on the efficacy of pyridaben. Also there was no significant difference in mixed function oxidase(MFO) activities between the S and PR-27 strains(RR 0.6). Iprobenfos(IBP) rolling as inhibitor of carboxylesterase showed low inhibition to PR-27 mite and esterase activity of resistant strain was lower than that of susceptible one(RR 0.7). It was proposed that metabolic detoxification by esterase and p450 oxidase did not play major role in mechanism of resistance to pyridaben in T. urticae.

Species 1: Acari Tetranychidae Tetranychus urticae (Two-spotted spider mite)
Keywords: Cross-resistance, pyridaben resistance

Poster (.pdf format, 356.0 kb)