Dynamics of imidacloprid resistance and cross-resistance in the brown planthopper, Nilaparvata lugens |
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Authors: | Yan Hua Wang Sheng Gan Wu Yu Cheng Zhu Jin Chen Feng Yi Liu Xue Ping Zhao Qiang Wang Zhen Li Xian Ping Bo & Jin Liang Shen |
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Institution: | Key Laboratory of Monitoring and Management of Plant Diseases and Insects, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China,;Institute of Quality and Standard for Agro-products, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang 310021, China,;Jamie Whitten Delta States Research Center, ARS-USDA, Stoneville, MS 38776, USA, and;Huizhou Agricultural Technology Extension Center, Huizhou, Guangdong 516001, China |
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Abstract: | Extensive use of imidacloprid for suppressing the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae), has placed heavy selection pressure on the target insect. A systematic study was carried out to determine imidacloprid resistance dynamics and cross-resistance. Data collected from a 3-year study (2005–2007) showed that in 2005, the resistance levels in Nanning (Guangxi), Haiyan (Zhejiang), and Nanjing and Tongzhou (Jiangsu) populations ranged from 200- to 799-fold compared with the susceptible strain. However, the resistance levels decreased to 135- to 233-fold in 2007, after reduced application of the chemical. A laboratory population was challenged with imidacloprid in successive generations. After 23 generations, the resistance ratio had increased from 200- to 1 298-fold. Continuous selection with imidacloprid could increase the resistance level even more than has already been developed in the population. Stopping selection with imidacloprid led to a rapid decrease of resistance from 759- to 114-fold after 17 generations. Resistance levels then became stable without decreasing any further. A similar result was also obtained from a study involving a field population (resistance ratio = 625-fold) collected from Tongzhou. At first, the population showed a rapid decrease in resistance right after imidacloprid selection was stopped, and then the resistance stabilized at a level of 105–129-fold. More interestingly, resistance increased again when selection was resumed. In addition, the resistant strain selected with imidacloprid showed substantial cross-resistance to imidaclothiz, thiacloprid, and acetamiprid, and slight levels of cross-resistance to dinotefuran and thiamethoxam, but no obvious cross-resistance to nitenpyram, buprofezin, and fipronil. The information from this study is valuable for formulating resistance-management strategies against N. lugens . |
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Keywords: | resistance stability Homoptera Delphacidae neonicotinoid insecticides resistance management rice |
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