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The depletion of zeta‐cypermethrin residues in bovine tissues and milk was studied. Beef cattle were treated three times at 3‐week intervals with 1 ml 10 kg?1 body weight of a 25 g litre?1 or 50 g litre?1 pour‐on formulation (2.5 and 5.0 mg zeta‐cypermethrin kg?1 body weight) or 100 mg kg?1 spray to simulate a likely worst‐case treatment regime. Friesian and Jersey dairy cows were treated once with 2.5 mg zeta‐cypermethrin kg?1 in a pour‐on formulation. Muscle, liver and kidney residue concentrations were generally less than the limit of detection (LOD = 0.01 mg kg?1). Residues in renal‐fat and back‐fat samples from animals treated with 2.5 mg kg?1 all exceeded the limit of quantitation (LOQ = 0.05 mg kg?1), peaking at 10 days after treatment. Only two of five kidney fat samples were above the LOQ after 34 days, but none of the back‐fat samples exceeded the LOQ at 28 days after treatment. Following spray treatments, fat residues were detectable in some animals but were below the LOQ at all sampling intervals. Zeta‐cypermethrin was quantifiable (LOQ = 0.01 mg kg?1) in only one whole‐milk sample from the Friesian cows (0.015 mg kg?1, 2 days after treatment). In whole milk from Jersey cows, the mean concentration of zeta‐cypermethrin peaked 1 day after treatment, at 0.015 mg kg?1, and the highest individual sample concentration was 0.025 mg kg?1 at 3 days after treatment. Residues in milk were not quantifiable beginning 4 days after treatment. The mean concentrations of zeta‐cypermethrin in milk fat from Friesian and Jersey cows peaked two days after treatment at 0.197 mg kg?1 and 0.377 mg kg?1, respectively, and the highest individual sample concentrations were 2 days after treatment at 0.47 mg kg?1 and 0.98 mg kg?1, respectively. © 2001 Society of Chemical Industry  相似文献   

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Field efficacy of five insecticides to a greenhouse strain ofFrankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) of known resistance status was studied. In a greenhouse trial, the mortality of aF. occidentalis strain (Uncali) which exhibited resistance only against cypermethrin in laboratory assays, reached 56%, 68%, 82%, 94% and 99%, 24 h after application of abamectin, cypermethrin, endosulfan, malathion and methomyl, respectively. In the laboratory, for larval mortality equal to that achieved in the field, much lower doses — half of the field dose of cypermethrin and endosulfan, and one-third and one-sixth of malathion and methomyl, respectively, were required in topical application. Because of differences between laboratory and field responses ofF. occidentalis to insecticides, a sound resistance evaluation program to determine field efficacy of insecticides is needed. Resistance increased 28.0- and 139.3-fold at LC50 in theF. occidentalis strain subjected to 27 and 44 cycles of cypermethrin selection, respectively. A slight cross-resistance of two- to threefold was found with endosulfan, malathion and methomyl and no cross-resistance was observed with abamectin. http://www.phytoparasitica.org posting August 4, 2008.  相似文献   

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Anti-cholinesterase resistance is in many cases caused by modified acetylcholinesterase (MACE). A comparison was made of toxicological data and AChE activity gathered from 21 field populations and nine laboratory strains of houseflies, Musca domestica L., to elucidate the best way of generating data to provide advice for management strategies and gathering information for resistance risk assessment on the organophosphates azamethiphos and dimethoate and the carbamate methomyl, which have been the primary insecticides used against adult houseflies in Denmark. Cluster analysis was performed and > 2000 houseflies were assigned to one of three phenotypes based on total acetylcholinesterase activity as well as inhibition by azamethiphos, methomyl or omethoate. A cluster, i.e. a phenotype, with high total AChE activity and high sensitivity to azamethiphos and less sensitivity to inhibition by methomyl and omethoate was shown to be linked to methomyl resistance. It was not possible to define any clusters that could be linked to azamethiphos or dimethoate resistance. The five mutations V180L, G262A, G262V, F327Y and G365A causing anticholinesterase resistance in houseflies were all identified in the Danish housefly strains. The data are very heterogeneous, and a correlation of molecular genetic background and resistance of phenotypes is not obvious with the available data.  相似文献   

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Progeny of house flies (Musca domestica L) from ten California poultry operations, three dairies and one horse-riding facility were tested for methomyl- and muscalure-treated bait resistance using up to three different assays: a topical assay, a no-choice feeding assay and a choice feeding assay. LD50 resistance factors from the topical assay, compared with a locally-derived susceptible colony, ranged between 1 and 4. LC50 resistance factors from the no-choice feeding assay ranged mostly between 2 and 5, with one value of 18. Measurable LT50 resistance ratios for female flies in the choice feeding assay ranged from 43 to 159; two populations had <10% mortality at 48h and could not be measured. LT50 resistance ratios for male flies in the choice feeding assay ranged from 26 to 96, and one population was too resistant to measure. A behavioral assay tested the feeding preference of male and female flies provided a dish of sugar and a dish of methomyl- and muscalure-treated bait. Of eight strains tested, females from seven strains and males from six strains showed significant preference for sugar over bait. Behavioral factors appear to be important in the severe resistance of house flies to baits in California.  相似文献   

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灭多威在蔬菜中残留与降解动态研究   总被引:2,自引:0,他引:2  
采用高效液相色谱法,系统地对灭多威在蔬菜中残留与降解进行动态检测。结果表明:灭多威在蔬菜中能够迅速降解,半衰期为30h。5d以后蔬菜中残留量基本低于0.01mg/Kg。  相似文献   

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棉蚜对灭多威的抗性稳定性研究   总被引:3,自引:0,他引:3  
将敏感棉蚜用灭多威选育20代,获得抗性倍数达142.37的高抗种群,在连续数代不接触药剂的情况下,其抗性水平呈下降趋势,停药12代后抗性基本稳定,但高于敏感种群5倍,以该种群进行恢复试验,其抗性发展速度更快,恢复8代时抗性出现突增,20代时抗性倍数达383.67。  相似文献   

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本文采用气相色谱法,用ECD检测器,OV-17毛细管柱,以氯菊酯为内标,在所选条件下,分析敌蚜螨中微量溴氰菊酯,该方法的线性相关系数为0.9994,变异系数为1.85%,回收率在97.8~102.4%。  相似文献   

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BACKGROUND: Beta-cypermethrin, a synthetic pyrethroid insecticide, was applied frequently in the control of health pests including houseflies, Musca domestica L., in China. However, different levels of resistance to beta-cypermethrin were monitored in field strains of houseflies. A strain of M. domestica, 4420-fold resistant to beta-cypermethrin after continuous 25 generations of selection, was used in this paper to determine the mode of inheritance of pyrethroid resistance. RESULTS: The estimated realized heritability (h(2)) of beta-cypermethrin resistance was 0.30 in this resistant strain. Results of bioassays showed no significant difference in values of LD(50) and slope of log dose-probit lines between reciprocal progenies F(1) and F'(1), and yielded values of - 0.10 (F(1)) and - 0.11 (F'(1)) for the degree of dominance (D). Chi-square analysis from responses of self-bred and backcross progenies (F(2), BC(1) and BC(2) respectively) indicated that the null hypothesis, a single gene responsible for resistance, was accepted. The minimum number of independent segregation genes was 0.93 for F(1) by Lande's method. CONCLUSION: It was concluded that beta-cypermethrin resistance in the housefly was inherited as a single, major, autosomal and incompletely recessive factor. These results would provide the basic information for pest management programmes.  相似文献   

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BACKGROUND: Chemical dissipation and organism immigration are considered important factors that influence recovery potential from perturbation of aquatic macroinvertebrates. Experiments were conducted to investigate the effect of simulated immigration on recovery of aquatic macroinvertebrates exposed in outdoor microcosms to ecotoxicologically similar concentrations of the rapidly dissipating pyrethroid insecticide cypermethrin (70 ng L−1) or the more persistent herbicide intermediate and degradate 3,4‐dichloroaniline (10 mg L−1). Microcosms were covered with light‐permeable mesh to prevent recolonisation. Immigration was simulated by the regular addition of organisms after treatment. RESULTS: Microcosms exposed to 3,4‐dichloroaniline treatment suffered substantial loss of taxon richness and by 10 months after treatment had only recovered where invertebrates had been added. Those treated with cypermethrin underwent an initial decline in certain crustacean and insect populations. These populations showed some signs of recovery over a period of 5 months through internal processes alone. However, rate of recovery was further enhanced where immigration was simulated, and in this case recovery had occurred around 100 days after treatment. CONCLUSION: Although not the only factors involved, simulated immigration and chemical fate clearly influence the ability of communities to recover from chemical exposure. Consideration of immigration processes and development of models will help to increase the realism of risk assessments. Copyright © 2009 Society of Chemical Industry  相似文献   

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The stability to heart of cis-permethrin and beta-cypermethrin in the solid phase was studied and the decomposition products identified. Samples heated at 210 degrees C in an oven in the dark showed that, in the absence of potassium chlorate (the salt present in smoke-generating formulations of these pyrethroids), cis-permethrin was not isomerized, although in the presence of that salt, decomposition was greater and thermal isomerization occurred. Other salts of the type KXO3 or NaXO3, with X being halogen or nitrogen, also led to a considerable thermal isomerization. Heating the insecticides in solution in the presence of potassium chlorate did not produce isomerization in any of the solvents assayed. Salt-catalysed thermal cis-trans isomerization was also found for other pyrethroids derived from permethrinic or deltamethrinic acid but not for those derived from chrysanthemic acid. The main thermal degradation processes of cis-permethrin and beta-cypermethrin decomposition when potassium chlorate was present were cyclopropane isomerization, ester cleavage and subsequent oxidation of the resulting products. Permethrinic acid, 3-phenoxybenzyle chloride, alcohol, aldehyde and acid were identified in both cases, as well as 3-phenoxybenzyl cyanide from beta-cypermethrin. A similar decomposition pattern occurred after combustion of pyrethroid fumigant formulations.  相似文献   

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血液中灭多威的提取和检验   总被引:1,自引:0,他引:1  
本文研究了水解法检验血液中的灭多威。将灭多威在碱性、90℃条件下水解成灭多威肟.通过GC/MS和GC/FPD分析。相对回收率在70%以上,该法高效,空白血液无干扰,重复性好,操作简单。  相似文献   

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乙基多杀菌素与4种杀虫剂复配对黄胸蓟马的联合毒力   总被引:1,自引:0,他引:1  
为筛选出与乙基多杀菌素复配具有增效作用的杀虫剂组合,采用叶管药膜法测定了乙基多杀菌素分别与啶虫脒、毒死蜱、阿维菌素、高效氯氰菊酯复配对黄胸蓟马2龄若虫的联合毒力,并采用共毒系数法评价了复配组合的联合作用。结果表明,乙基多杀菌素与啶虫脒在配比为3∶7、5∶5、7∶3和8∶2时,与毒死蜱在所有配比组合中,与阿维菌素在配比为2∶8、3∶7和6∶4时,其共毒系数(CTC)均大于120,表现出显著的增效作用;而与高效氯氰菊酯在所有配比下均不具有增效作用。乙基多杀菌素与啶虫脒、毒死蜱、阿维菌素采用上述具有增效作用的复配比复配,在害虫治理和抗性治理中具有一定的应用前景和开发潜力。  相似文献   

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开展了 60g/L乙基多杀菌素悬浮剂在杨梅上的残留田间试验,对乙基多杀菌素及其代谢物在杨梅中的残留量及消解动态进行了分析,为乙基多杀菌素在杨梅上的膳食风险评估、合理使用及制定残留限量标准提供依据。建立了液相色谱串联质谱法(LC-MS/MS)测定杨梅中乙基多杀菌素及其代谢物的残留量的分析方法。当乙基多杀菌素及其代谢物在杨梅中的添加浓度为0.05、1.0, 2.0mg/kg时,平均回收率82.6%-96.6%,相对标准偏差为3.3%-7.4%,符合残留检测方法的要求。消解动态试验结果显示,乙基多杀菌素在杨梅中的消解动态规律符合一级动力学方程,半衰期为0.9~2.6d,属易降解农药。最终残留试验表明60g/L乙基多杀菌素悬浮剂按有效成分40和60mg/kg,施药1次和2次,末次施药后1、2、3、5、7d,杨梅中乙基多杀菌素最终残留量分别为<0.05 ~0.38mg/kg、<0.05 ~ 0.39mg/kg、< 0.05 ~ 0.32mg/kg、< 0.05 ~ 0.19mg/kg、< 0.05 -0.11 mg/kg0 建议在杨梅上使用60g/L乙基多杀菌素悬浮剂时,有效成分用药量40mg/kg,施药1次,安全间隔期7d。  相似文献   

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Pesticides can modify invertebrate movement and feeding behaviour which could reduce predation in agroecosystems. Previous assays have exposed the spider Pardosa amentata (Clerck) to the synthetic pyrethroid cypermethrin and monitored prey items consumed in small containers (requiring very little movement to capture prey). The current study used larger arenas containing artificial 'vegetation' (a plastic analogue) to encourage spiders to hunt and capture prey. The period 24 h after exposure produced greatest variability in prey item consumption between treatments and was used to examine treatment effects. At this time, cypermethrin reduced prey consumption rates but these effects did not persist. Findings did not suggest that the presence of artificial vegetation in arenas modified prey consumption rates, which was consistent for individuals treated with cypermethrin and a control group. This is despite the majority of pesticide-treated individuals exhibiting both ataxia and paralysis of the hind legs (these effects persisting for a maximum of 3 and 6 days respectively). These findings were consistent for both sexes. Spider longevity under starvation conditions was not significantly reduced by cypermethrin exposure but overall females survived longer than males. The findings are discussed in the context of the arenas used and the ecology of this common predator.  相似文献   

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本文采用5%OV-17为色谱柱固定相,以邻苯二甲酸二正戊酯为内标物,用FID检测器对2%甲嘧磷 马粉剂进行定量分析,甲基嘧啶磷、马拉硫磷的标准偏差分别为0.027、0.011,变异系数分别为2.40%、0.99%; 甲基嘧啶磷回收率为99.5%-100.3%,马拉硫磷的回收率为98.9%~99.8%o该方法方便、快捷、准确。  相似文献   

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