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【目的】研究噻虫嗪种衣剂在棉叶中的消解动态,评价其对棉蚜的防治效果。【方法】采用QuEChERS-UPLC-MS/MS方法,定期测定棉叶中噻虫嗪的含量,田间调查噻虫嗪种衣剂对棉蚜防治效果。【结果】0.01~0.50 mg/L线性关系良好,相关系数r=0.999。在0.01、0.20、0.50 mg/kg添加水平下,噻虫嗪在棉叶中的平均回收率在93.4%~119.71%,相对标准偏差为0.34%~5.18%,方法检测限为0.001 mg/kg。噻虫嗪在棉叶中的消解动态符合一级动力学方程,半衰期为3.85~4.03 d。下部叶中噻虫嗪含量分别占各处理总浓度的59.42%~76.39%,噻虫嗪主要分布在下部叶片。出苗后30 d时,600 g/100kg处理防效最佳,仍可达87.90%。【结论】使用600 g/100kg浓度噻虫嗪种子处理,可较好地防治苗期蚜虫。 相似文献
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While the toxic effects of neem, Azadirachta indica A. Juss, on Bemisia tabaci Genn. are well documented, few studies have evaluated other oils. We compared neem, sesame, citrus, castor, vegetable and mineral oils (1% v/v) to a chemical standard thiamethoxam (0.17 g A.I./L) against B. tabaci biotype B life stages on dry bean plants Phaseolus vulgaris L. under screenhouse conditions. Oils and thiamethoxam exhibited low ovicidal activity (<10% egg mortality). However, significant mortality occurred due to the residual activity to 1st instars that emerged from treated eggs. Overall, impacts of egg treatments were greatest for thiamethoxam (77% total mortality for eggs and 1st instars) compared with oils which were statistically similar (22–29% mortality). Larvicidal effect of oils (against 2nd instars) was greater than ovicidal effects. Highest nymphal mortality (>81%) was achieved with castor, sesame, citrus and neem oils, which was significantly greater than for thiamethoxam (65% mortality). Adult whiteflies were exposed to fresh and aged spray residues, rather than being sprayed directly. In this case, comparatively lower efficacy was achieved from oil treatments compared with thiamethoxam. While some mortality was observed from fresh residues of slow drying oils (up to 41% for castor oil), no significant control from any oil residues >3 days old was observed in our tests. The different route of exposure against adults likely reduced the effectiveness of oil treatments which act directly on the cuticle. In trials with viruliferous adult whiteflies exposed to fresh residues, none of the tested products completely prevented transmission of bean golden mosaic virus (BGMV). However, we noted reduced virus severity ratings from plants pre-treated with castor and citrus oil. We conclude that castor, sesame, citrus and neem oils have the potential to be used in whitefly management programs. 相似文献
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Bradysia odoriphaga Yang and Zhang (the chive gnat) is the major insect pest affecting Chinese chives (Allium tuberosum Rottl. ex Spreng.) in Northern China. Only three insecticide products are registered for its control. In the present study, we compared the persistence and distribution of thiamethoxam and phoxim in soil and determined their long-acting control effects against B. odoriphaga and two other secondary pests, Thrips alliorum Priesner and the Asiatic onion leaf miner Acrolepia alliella Semenov and Kuznetsov (Lepidoptera: Acrolepiidae), after a single soil application using the directional spray-washing method during the early Chinese chive root-rearing period. Under the same applied dosage, the rhizosphere soil at a depth of 4.0–10.0 cm had concentrations of thiamethoxam and phoxim ranging from 2.21 to 7.44 mg/kg and 0.09–0.44 mg/kg, respectively, at the 7th day after application. The half-lives of thiamethoxam and phoxim in the soil were 27.5 and 6.7 days, respectively. Thiamethoxam persisted for 210 days, whereas phoxim only persisted for 45 days in the soil and plants. In addition, thiamethoxam applied at 6.0 kg a.i./ha maintained a low population density of B. odoriphaga, T. alliorum and A. alliella for nine months longer than phoxim. In conclusion, thiamethoxam may help farmers more effectively manage B. odoriphaga and other secondary pests on Chinese chive and reduce the costs of insecticide use while sustaining protection. 相似文献
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小麦和土壤中噻虫嗪残留及消解动态分析 总被引:3,自引:0,他引:3
为对噻虫嗪在小麦生产上应用的安全性进行评价,通过对小麦籽粒、植株和土壤进行前处理及在样品中添加噻虫嗪,建立其残留量定量检测分析方法;通过两年三地的残留试验,分析了小麦籽粒、植株和土壤中噻虫嗪的残留及消解动态,并对小麦籽粒中的残留量进行风险评估。结果表明,噻虫嗪在小麦籽粒、植株及土壤空白添加平均回收率为79.62%~94.70%,相对标准偏差为0.91%~6.56%,其最小检出量为5.0×10-8g,小麦籽粒、植株及土壤中的最低检测浓度均为0.01mg·kg-1。该检测方法重现性好,准确度、精密度高,可满足噻虫嗪在小麦及土壤中的残留分析要求。2011和2012年,河南、黑龙江和江苏三地噻虫嗪在小麦植株和土壤中的消解半衰期分别为0.85~2.24d和2.77~4.79d;通过不同施药次数、施药量及间隔采样检测,噻虫嗪在小麦籽粒中的最终残留量均≤0.038mg·kg-1,占日允许摄入量的15.04%左右(普通人群噻虫嗪的国家估算每日摄入量是0.25mg),因此按本试验方式进行施药,通常不会对一般人群健康产生不可接受的风险。 相似文献
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[目的]研制20%噻虫嗪油悬剂。[方法]采用湿法研磨工艺配制了20%噻虫嗪油悬浮剂,对其配方中的分散介质、乳化剂、润湿分散剂、增稠剂进行了筛选,并对该制剂进行了理化性能测定。[结果]20%噻虫嗪油悬剂的最佳质量配比为:噻虫嗪原药20.00%,脂肪酸甲酯71.30%,OP-4 0.40%,农乳500#3.00%,EC80 3.00%,黄原胶0.30%,白炭黑2.00%。该制剂外观无明显分层,水中分散性良好,各项指标均符合油悬浮剂的相关标准。[结论]按该配方配制的20%噻虫嗪油悬浮剂工艺简单、对环境污染小,具有较好的市场开发前景。 相似文献
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Spinetoram, imidacloprid, thiamethoxam and chlorantraniliprole are new insecticides with novel mode of actions, low mammalian toxicity and low impact to environment. In the present study, the efficacy of these insecticides was tested against Tribolium confusum Jacquelin du Val on concrete. Among the tested insecticides, spinetoram proved to be more effective, providing complete control of T. confusum adults and young larvae after 14 days of exposure. For the young larvae, thiamethoxam at the highest dose and chlorantraniliprole at both doses were equally effective with spinetoram. On the other hand, none of the tested insecticides were able to control T. confusum pupae. Moreover, none of the insecticides had ovicidal effect, with the exception of chlorantraniliprole in some combinations. From the mobile life stages, the most tolerant life stages were old larvae and the most susceptible young larvae. The presence of food (flour) moderated T. confusum mortality. From the results of the present study, we can conclude that spinetoram, thiamethoxam and chlorantraniliprole showed potential and need be further evaluated for surface treatments in stored product facilities. Our work underlined the need for good cleaning and sanitation procedures in warehouses and food processing facilities. 相似文献
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Bactericera cockerelli is a pest on multiple solanaceous crop plants and is the sole vector for the bacteria Candidatus Liberibacter psyllaurous. When the pathogen is present, feeding by these psyllids results in ‘vein greening’ disease in peppers and tomatoes, and “zebra chip” disease in potatoes. Currently, management is based entirely on the application of pesticides, including two neonicotinoid compounds. Populations of B. cockerelli collected in southern Texas in 2006 and 2012 were examined for reduced susceptibility and behavioral responses to imidacloprid.Tests comparing imidacloprid and thiamethoxam demonstrated that both can reduce nymph numbers in the field, but retention and effective periods vary among application methods and compounds. In addition, imidacloprid and thiamethoxam are both sensitive to the amount of water applied during irrigation. Collectedly, these results suggest that imidacloprid is unlikely to be effective in controlling B. cockerelli in south Texas. Moreover, its use needs to be carefully considered in other locations even where resistance has not yet been detected. Finally, thiamethoxam may be useful, but careful attention must be paid to irrigation and rainfall level, application method, and timing of application. 相似文献
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采用25%阿克泰(Thiamethoxam)可分散性粒剂4000~8000倍液进行移栽后喷雾和采用阿克泰WG2000~4000倍液进行移栽前苗期灌根处理,对番茄烟粉虱的防治效果均明显好于对照药剂,表明阿克泰WG对烟粉虱具有较高活性。试验结果表明,阿克泰WG对烟粉虱的若虫也具有较好的杀伤效果。施用阿克泰WG对番茄植株安全。 相似文献