A sublethal dose of thiamethoxam causes a reduction in xylem feeding by the bird cherry-oat aphid (Rhopalosiphum padi), which is associated with dehydration and reduced performance
A sublethal dose of thiamethoxam causes a reduction in xylem feeding by the bird cherry-oat aphid (Rhopalosiphum padi), which is associated with dehydration and reduced performance
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DOI：
10.1016/j.jinsphys.2009.03.002
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发表时间：
2009-08-01
影响因子：
2.2
通讯作者：
Pritchard, J.
中科院分区：
文献类型：
--
作者：
Daniels, M.;Bale, J. S.;Pritchard, J.
蚜虫主动摄取木质部汁液被认为是补液的重要机制。当饥饿的鸟樱桃燕麦蚜虫（Rhopalosiphum padi）被允许以亚致死剂量的木质部流动新烟碱类噻虫嗪处理过的小麦（Triticum aestivum）为食时，使用电穿透图分析摄食行为显示，在去除毒素后，木质部摄食减少。为了验证取食木质部行为作为补液机制的重要性，研究了亚致死剂量噻虫嗪对蚜虫含水量、蜜露排泄、生长和繁殖力的影响。与取食蒸馏水处理小麦的蚜虫相比，取食噻虫脒处理小麦的饥饿斑胸蚜体内水分含量显著降低（74.5 +/- 0.23和75.6 +/- 0.18%）。分别)。此外，亚致死剂量噻虫嗪对蚜虫生产性能有不利影响。在生殖成熟期，经噻虫嗪处理的小麦上出生的蚜虫明显较小（体表面积1.07±0.03 mm(2)）。与蒸馏水处理的小麦蚜相比（分别为1.87 +/- 0.02 mm(2)、0.72 +/- 0.03 mg、11.28 +/- 0.58若虫/d），较轻（0.31 +/- 0.04 mg），较少（2.85 +/- 0.36若虫/d）。不管观察到的木质部摄食损伤是由于神经毒性还是反摄食效应，这些结果对商业作物保护具有重要意义，因为亚致死剂量噻虫嗪的行为改变效应可能会改变该农药在整个生长季节的功效。2009爱思唯尔有限公司版权所有。
The active ingestion of xylem sap by aphids is hypothesised to be an important mechanism for rehydration. When starved bird cherry-oat aphids (Rhopalosiphum padi) were allowed to feed on wheat (Triticum aestivum) treated with a sublethal dose of the xylem-mobile neonicotinoid thiamethoxam, analysis of feeding behaviours using the electrical penetration graph revealed a reduction in xylem feeding that was reversed on removal of the toxin. To test the importance of xylem-feeding behaviour as a rehydration mechanism, the effects of the sublethal dose of thiamethoxam on aphid water content, honeydew excretion, growth and fecundity were investigated. Body water contents of starved R. padi feeding on wheat treated with thiamethoxam were significantly reduced compared to aphids feeding on wheat treated with distilled water (74.5 +/- 0.23 and 75.6 +/- 0.18%. respectively). In addition, the sublethal dose of thiamethoxam had detrimental effects on aphid performance. At reproductive maturity, aphids that had been born on wheat treated with thiamethoxam were significantly smaller (as measured by body plan area; 1.07 +/- 0.03 mm(2)). lighter (0.31 +/- 0.04 mg) and less fecund (2.85 +/- 0.36 nymphs/day) than aphids born on wheat treated with distilled water (1.87 +/- 0.02 mm(2), 0.72 +/- 0.03 mg, 11.28 +/- 0.58 nymphs/day, respectively). Regardless of whether the observed impairment of xylem feeding is due to a neurotoxic or an antifeedant effect, these results have important implications for commercial crop protection as the behaviour-modifying effects of the sublethal dose of thiamethoxam may change the efficacy of this pesticide throughout the growing season. (C) 2009 Elsevier Ltd. All rights reserved.