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为了寻求水稻中快速定量检测呋虫胺的方法,稻田土壤、糙米、稻壳及植株样品采用改良的QuEChERS法处理,稻壳和植株样品采用PSA和C18吸附剂净化,LC-MS/MS检测,外标法定量,建立改良QuEChERS/LC-MS/MS联用分析检测水稻田中的呋虫胺.结果表明:在0.015～0.4 mg/kg添加水平范围内,稻田土壤、糙米、稻壳以及植株中的平均回收率分别为92.32％～97.45％,93.90％～101.0％,84.30％～99.20％和77.50％～79.00％;相对标准偏差(RSD,n=5)分别为3.52％～4.32％,1.20％～2.60％,0.60％～3.30％和1.20％～2.00％.此方法的最低检测限(LOD)为1.75×10-12 g,最低定量限(LOQ)为5.84×10-12 g.该方法前处理简便,快速,灵敏度高,重现性好,符合农药检测分析的技术要求.     

50％呋虫胺·吡蚜酮可湿性粉剂的高效液相色谱分析方法研究

[目的]建立呋虫胺·吡蚜酮制剂含量的高效液相色谱分析方法.[方法]以乙腈-水溶液作为流动相,采用Agilent XDB C18柱和二极管阵列检测器同时测定有效成分呋虫胺和吡蚜酮的含量.[结果]呋虫胺和吡蚜酮在100 ～ 500 mg/L浓度范围内线性关系良好,相关系数(r)分别为0.9998和0.9996;标准偏差分别为0.045和0.063,相对标准偏差分别为0.11％和0.61％;平均回收率分别为99.79％和99.64％.[结论]试验建立的高效液相色谱方法操作简便,精密度与准确度完全符合分析检验要求,可同时快速测定呋虫胺和吡蚜酮含量.     

20％呋虫胺SG防治稻褐飞虱田间药效研究

[目的]探索20％呋虫胺SG防治稻褐飞虱田间药效。[方法]用20％呋虫胺SG和80％中农倍利SG,探讨20％呋虫胺sG防治稻褐飞虱田间药效。[结果]田间防效比较试验显示,用20％呋虫胺SG 150、225、300、375g／hm。防治稻褐飞虱,其田间防效药后3d分别为53．02％、70．06％、71．73％、74．74％;药后7d分别为68．96％、78．44％、80．19％、84．19％;药后14d分别为75．84％、83．23％、88．32％、91．26％;药后21d分别为72．10％、87．55％、90．46％、91.24％。[结论]20％呋虫胺SG是目前防治稻褐飞虱的理想药剂,可用20％呋虫胺SG300g/hm2对水675kg/hm^2均匀透彻喷雾。     

20%呋虫胺悬浮剂的高效液相色谱分析

为了解决呋虫胺悬浮剂含量在分析上方法不足,以及采用液相色谱法测定时流动相选择,仪器条件的确定时所遇到的问题,采用岛津LC-10AT液相色谱仪为基础,利用2.5 cm×4.6 mm不锈钢,内装C18、5 μm填充物,乙腈+水+冰乙酸+三乙胺为流动相对呋虫胺悬浮剂有体的含量进行检测。结果表明采用该流动相以及仪器条件下,呋虫胺有效体含量的不存在异构体峰重叠现象。主峰与杂质峰的分离度最好,峰形良好。此次研究证明,20%呋虫胺悬浮剂分析方法的提出不仅填补了该烟碱类杀虫剂总含量分析方法的空白,而且测定便捷、准确、可行,利于生产企业用来质控。     

2种药剂防治水稻中后期褐飞虱的效果研究

[目的]了解50％呋虫胺水分散粒剂、60％吡蚜酮·噻嗪酮可湿性粉剂防治水稻褐飞虱的效果,确定其最佳使用剂量.[方法]通过田间小区药效试验研究了50％呋虫胺水分散粒剂、60％吡蚜酮·噻嗪酮可湿性粉剂对水稻中后期褐飞虱的防治效果、持效时间和最佳使用剂量.[结果]在褐飞虱卵孵化高峰期使用50％呋虫胺水分散粒剂180 g/hm2或者60％吡蚜酮·噻嗪酮可湿性粉剂600 g,/hm2,药后23 d防效可达90％以上,且对作物安全,对天敌影响较小.[结论]该2种供试药剂在水稻中后期防治3代褐飞虱有较好的持效性,可望进一步研究开发.     

Understanding the dynamics of neonicotinoid activity in the management of Bemisia tabaci whiteflies on poinsettias

The relative efficacies of registered label rates for foliar and soil drench treatments of imidacloprid and dinotefuran at preventing the establishment of Bemisia tabaci B biotype whitefly populations on newly infested poinsettia plants were evaluated. Pesticide levels within and on plant leaves were monitored for 10 weeks by ELISA and LC/MS in an effort to better understand the dynamics of neonicotinoid activity against this insect and to estimate insecticide concentrations needed to kill the nymphal and adult stages. While all treatments proved equally effective as a remedial measure for the control of the resident adult populations, thereby accomplishing the objective of foliar contact treatments, the dinotefuran soil drench application was the only treatment that provided multi-generational control of Bemisia populations.     

25%吡蚜酮磺酸盐·呋虫胺可分散油悬浮剂研制及应用

为开发防治水稻稻飞虱和小麦蚜虫的药剂,采用共毒系数法确定吡蚜酮磺酸盐和呋虫胺的最佳配比,筛选助剂体系获得25%吡蚜酮磺酸盐·呋虫胺可分散油悬浮剂(OD)最优配方,并考察制剂对水稻稻飞虱及小麦蚜虫的田间药效。最优配方为:吡蚜酮磺酸盐12.5%、呋虫胺12.5%、农乳601#8%、T-809%、SP SC-3 5%、改性土4%,油酸甲酯补足至100%。田间药效试验显示,25%吡蚜酮磺酸盐·呋虫胺OD对稻飞虱及小麦蚜虫的速效性、防效均高于对照药剂。25%吡蚜酮磺酸盐·呋虫胺OD的各项性能指标符合可分散油悬浮剂的要求,对水稻稻飞虱及小麦蚜虫有较好的防效。     

Seasonal timing of neonicotinoid and organophosphate trunk injections to optimize the management of avocado thrips in California avocado groves

The timing of trunk injections of the organophosphate, acephate, and two systemic neonicotinoids, imidacloprid and dinotefuran, was evaluated in field trials for the management of avocado thrips. Following treatments, leaves were sampled over a 6-month period to determine the period of efficacy for each insecticide. The efficacy of acephate was determined using bioassays. Imidacloprid and dinotefuran residues in leaves were quantified by ELISA to determine the window of efficacy for these treatments based on previously determined biological dose response data. In addition, residues in fruit were quantified to determine whether trunk injection of insecticides might present a greater risk for contaminating fruit than traditional application methods. The timing of trunk injection treatments significantly impacted the uptake of imidacloprid and dinotefuran, with mid- and late-leaf flush periods proving more effective in terms of rate of uptake and degree of persistence at threshold levels. Acephate was mobilized very rapidly and gave good control of thrips in bioassays; however, residues of acephate, and its insecticidal metabolite methamidophos, were detected in the fruit for up to 4 weeks after injection. Imidacloprid was most effective when injected during the mid-flush period, which allowed levels to establish within the trees over a period of time when thrips would be actively feeding on young leaf tissue. The establishment of dinotefuran in trees was very rapid following trunk injection. However, its use was compromised by the inability of the chemical to reach effective concentrations for thrips control. Residues of dinotefuran were detected in fruit sampled from one tree, but the levels were below typical MRLs for other crops treated with this insecticide. Imidacloprid was not detected in any fruit sampled from trees in which imidacloprid had established in leaf tissue at concentrations that were toxic to avocado thrips. Overall, trunk injection of imidacloprid could be a viable option for avocado thrips control. However, residues of acephate in fruit may preclude its use because of the requirement for increased pre-harvest intervals. Dinotefuran injections may also be useful due to the rapid uptake and establishment within the canopy; however, it will be necessary to determine whether higher doses of dinotefuran can deliver the required levels of insecticide necessary for thrips control, without contaminating the fruit with residues.     

Evaluation of neonicotinoids as pyrethroid alternatives for rice water weevil management in water-seeded rice

The rice water weevil (RWW), Lissorhoptrus oryzophilus (Kuschel) (Coleoptera: Curculionidae), is the most destructive insect pest of rice in the United States. Water-seeded rice, which is flooded at an earlier stage of crop development than drill-seeded rice, is at heightened risk of loss from root-feeding RWW larvae. Pyrethroids, the most widely used group of foliar insecticides for RWW control, have inherent limitations such as limited residual activity, narrow window of activity and extreme toxicity to non-target aquatic organisms. An array of field, lab and greenhouse experiments was conducted to compare the activity of two neonicotinoids with that of λ-cyhalothrin, a widely used pyrethroid, against the RWW. Small-plot efficacy trials were conducted during 2009, 2010 and 2011. Foliar clothianidin (Belay 2.13 SC) and a granular formulation (3%) of dinotefuran applied to plots were as effective as, and showed greater residual activity than, foliar applications of λ-cyhalothrin. Topical bioassays on adult weevils revealed that clothianidin possessed lower contact toxicity than λ-cyhalothrin. Residual assays using weevils placed on foliage of sprayed plots revealed that the toxic and sublethal behavioral effects of clothianidian on adult weevils were more persistent for clothianidin than for λ-cyhalothrin. Granular dinotefuran applied to greenhouse-grown plants previously infested with weevil larvae showed excellent larvicidal activity. Overall, these studies showed that neonicotinoids have potential as pyrethroid replacements against the RWW in water-seeded rice culture.     

不同药剂防治秋豇豆白粉虱效果探讨

为减轻豇豆白粉虱的发生,减少化学农药用量、残留和环境污染,采用测报调查、随机区组设计和统计分析等方法,开展了化学农药呋虫胺、啶虫脒和吡蚜酮,生物农药阿维菌素防治豇豆温室白粉虱农药田间药效试验.结果表明:在温室大棚秋季豇豆白粉虱发生较重情况下,每1.8％阿维菌素EC 375 g/hm2、20％呋虫胺SP(护瑞)600 g、5％啶虫脒WP 600 g、25％吡蚜酮WP 600 g(对照药剂),5～8天施药1次,连续施用3次,药后7、14、20 d,防治效果分别达90.9％、97.0％、88.0％、93.9％,97.4％、92.1％、84.2％、89.4％和95.6％、86.7％、82.2％、84.5％,且药后7d呋虫胺与阿维菌素和吡蚜酮,极显著高于啶虫脒,阿维菌素与啶虫脒和吡蚜酮之间差异不显著;药后14 d,阿维菌素与呋虫胺和吡蚜酮差异不显著,极显著高于啶虫脒,呋虫胺与吡蚜酮差异不显著,显著高于啶虫脒;药后20d,阿维菌素极显著高于呋虫胺、啶虫脒和吡蚜酮,呋虫胺与啶虫脒和吡蚜酮差异不显著.同时,生物农药阿维菌素在药后7d,防效稍低于化学农药呋虫胺,药后14d,防效高于呋虫胺,药后20d,防效极显著高于呋虫胺.这4种药剂尤其是生物农药阿维菌素不仅可以作为防治温室白粉虱的理想药剂,而且可以作为现代农业示范区、无公害农产品、绿色农产品和有机农产品的理想药剂.