title: Baseline Susceptibility of Plutella xylostella (Lepidoptera: Plutellidae) to the Novel Insecticide Spinetoram in China.
abstract: Spinetoram is a spinosyn, which is a unique class of natural insecticide. Because of its novel mode of action, spinetoram is more potent and faster acting than other insecticides, even the older spinosyn product, spinosad. On account of being efficient on insect order Lepidoptera, spinetoram provides a new alternative for control of Plutella xylostella (L.) (Lepidoptera: Plutellidae), which are resistant to other chemicals. To determine the current situation of resistance of P. xylostella to spinetoram, the susceptibility of 16 P. xylostella populations from different regions of China or different time in addition to the population from laboratory was assessed using a leaf dip bioassay. The variation in spinetoram susceptibility among the 16 field populations was narrow, with median lethal concentrations (LC50 values) ranging from 0.131 to 1.001 mg/liter. Toxicity ratios (TRs) ranged from 1.5 to 7.6 and were 5.6 and 7.6 for populations SY-2 and FX-1, respectively, indicating some low level of tolerance in these populations. A discriminating concentration (a concentration that can detect the occurrence of resistance in a population) of 10 mg/liter, which was identified based on the pooled toxicological data, caused 100% mortality in all nine tested populations. The baseline susceptibility data reflect the natural variation of the P. xylostella populations to spinetoram rather than variation caused by previous exposure.
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Weidi
authors.initials: W
authors.lastname: Li
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China. Corresponding author, e-mail: zhanginsect@163.com.
authors.forename: Jingming
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Pengjun
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Wencai
authors.initials: W
authors.lastname: Lin
authors.affiliation: Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
authors.forename: Qingsheng
authors.initials: Q
authors.lastname: Lin
authors.affiliation: Institute of Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China.
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Li
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Hang
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Zhijun
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Institute of Plant Protection and Microbiology, Zhejiang Academy of Agricultural Sciences, State Key Laboratory Breeding Base for Zhejiang Sustainable Pest and Disease Control, Hangzhou 310021, China.
authors.forename: Yaobin
authors.initials: Y
authors.lastname: Lu
mesh_terms: D000818:Animals; D002681:China; D007306:Insecticides; D018942:Macrolides; D009036:Moths
chemical_list: D007306:Insecticides; D018942:Macrolides; C548262:spinetoram
keywords: Plutella xylostella; discriminating concentration; geographic variation; spinetoram; susceptibility