title: Lethal and sublethal effects of thiamethoxam on the whitefly predator Serangium japonicum (Coleoptera: Coccinellidae) through different exposure routes.
abstract: Given expectations for a booming usage of thiamethoxam and increasing availability of the promising biological agent Serangium japonicum for the control of Bemisia tabaci in China, an evaluation of their compatibility is crucial for integrated pest management (IPM). This study examined the lethal and sublethal effects of thiamethoxam on S. japonicum through three exposure routes. An acute toxicity bioassay showed that LC50 values of thiamethoxam for S. japonicum through residue contact, egg-dip, and systemic treatment were 6.65, 4.37, and 2.43 mg AI L(-1), respectively. The prey consumption of S. japonicum given different densities of B. tabaci eggs under control, discontinuous, egg-dip and systemic exposure scenarios showed a good fit to a Type II functional response. Predation of S. japonicum was most affected under systemic exposure, followed by egg-dip, and discontinuous, which was only slightly affected. In all cases tested, however, predators recovered their predation capacity rapidly, either after 24h of exposure or 24h after the end of exposure. Thiamethoxam was highly toxic to S. japonicum regardless of exposure routes. Sublethal effects of thiamethoxam applied systemically or foliar both impaired the biological control of S. japonicum on B. tabaci. Therefore, thiamethoxam should be used with caution in IPM of B. tabaci.
authors: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, People's Republic of China.
authors: Feng-Luan
authors: FL
authors: Yao
authors: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, People's Republic of China.
authors: Yu
authors: Y
authors: Zheng
authors: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, People's Republic of China.
authors: Jian-Wei
authors: JW
authors: Zhao
authors: French National Institute for Agricultural Research (INRA), 400 Route des Chappes, 06903 Sophia Antipolis, France.
authors: Nicolas
authors: N
authors: Desneux
authors: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, People's Republic of China. Electronic address: yuxianhe_faas@sina.cn.
authors: Yu-Xian
authors: YX
authors: He
authors: Institute of Plant Protection, Fujian Academy of Agricultural Sciences, Fuzhou 350013, People's Republic of China. Electronic address: wengqy@faas.cn.
authors: Qi-Yong
authors: QY
authors: Weng
mesh_terms: D000818:Animals; D002681:China; D001517:Coleoptera / Q000187:drug effects*; D005260:Female; D007306:Insecticides / Q000633:toxicity*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000633:toxicity*; D010078:Oxazines / Q000633:toxicity*; D011235:Predatory Behavior / Q000187:drug effects*; D000077922:Thiamethoxam; D013844:Thiazoles / Q000633:toxicity*
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D013844:Thiazoles; D000077922:Thiamethoxam
keywords: Bemisia tabaci; Functional response; Hazard quotient; Integrated pest management; Neonicotinoid; Risk assessment