杀虫气雾剂中胺菊酯、氯菊酯、α-氯氰菊酯的毛细管气相色谱分析

本文研究了用毛细管气相色谱柱和ECD检测器测定杀虫气雾剂中胺菊酯、氯菊酯、α -氯氰菊酯(氯氰菊酯 )含量的方法。在所选择的操作条件下 ,氯氰菊酯中α -氯氰菊酯的最小分离度达1.10,胺菊酯、氯菊酯的2对顺反异构体也得到完全分离。采用内标法定量。平行测定胺菊酯、氯菊酯、α -氯氰菊酯的变异系数分别为0.008%,0.006%,0.046%。添加回收率为 :胺菊酯99.06%～99.86%,氯菊酯98.97%～99.25%,α -氯氰菊酯97.89%～102.59%。     

杀虫气雾剂中胺菊脂、氯菊酶、α—氯氰菊酯的毛细管气相色谱分析

本文研究了用毛细管气相色谱柱和ECD检测器测定杀虫气雾剂中胺菊酯，氯菊酯，α－氯氰菊酯（氯氰菊醒）含量的方法。在所选择的操作条件下，氯氰菊酯中α－氯氰炙酯的最小分离度达1．10，胺菊酯，氯菊酯的2对顺反异构体也得到完全分离。采用内标法定量。平行测定胺菊酯，氯菊酯，α－氯氰菊酯的变异系数分别为0.008%,0.006,0.046%,添加回收率为：胺菊酯99.06%-99.86%,氯菊酯98．97％－99．25％，α－氯氰菊酯98.89%-102.59％。     

毒死蜱·高效氯氟氰菊酯22%水乳剂的高效液相色谱分析方法

本文叙述了采用高效液相色谱法以乙腈∶水(4∶1)为流动相,C18柱和紫外检测器同时定量分析了混剂中的毒死蜱和高效氯氟氰菊酯的含量。结果表明,毒死蜱和高效氯氟氰菊酯的标准偏差分别为0.124 6、0.021 21;变异系数分别为0.62%、1.03%;平均回收率分别为100.49%、100.36%,线性相关系数分别为r毒死蜱=0.999 7、r高效氯氟氰菊酯=0.999 9。     

高效氯氟氰菊酯与烯啶虫胺增效混配剂的筛选及其对小麦蚜虫的田间防治效果

为了延缓麦蚜抗药性和降低杀虫剂使用量,本研究筛选了具有增效作用的高效氯氟氰菊酯和烯啶虫胺的复配比例,并研究了增效复配剂对麦蚜的田间防治效果。浸叶法测定结果表明,高效氯氟氰菊酯对麦蚜的LC50为25.01 mg/L,烯啶虫胺对麦蚜的LC50为28.21 mg/L。通过最佳增效配比的筛选,发现高效氯氟氰菊酯和烯啶虫胺的有效成分比为1.3∶1、1∶1.1、1∶1.7、1∶10.2时,对麦蚜的毒效比分别为1.28、1.49、1.64、1.50,表现为增效作用。深入研究发现高效氯氟氰菊酯和烯啶虫胺的有效成分为1∶4.5、1∶7.5和1∶10.2的混配组合的共毒系数均显示了显著增效作用,其中,当高效氯氟氰菊酯与烯啶虫胺有效成分比为1∶7.5时,混配剂的LC50为5.22 mg/L,共毒系数达到532.61。按有效成分比1∶7.5,将10%高效氯氟氰菊酯水乳剂与20%烯啶虫胺可溶液剂混用后,进行田间试验,结果表明,在药后1、3 d和7 d,混配剂的防效与高效氯氟氰菊酯单剂的防效无显著性差异,在药后1 d,混配剂的防效高于烯啶虫胺单剂的防效,在药后3 d及7 d,混剂与烯啶虫胺单剂的防效没有显著差异。混配剂的防效在药后7 d内不断上升,其中药后7 d防效达到92.98%。混配剂的使用可以达到对高效氯氟氰菊酯减量的目的,同时保证了对麦蚜的防效。     

加拿大将开展“拟除虫菊酯类农药”再评价

加拿大有害生物防治管理局（PMRA）将对拟除虫菊酯、除虫菊酯以及相关的增效剂等拟除虫菊酯类农药开展再评价工作,旨在建立拟除虫菊酯类农药的风险评估和风险管理办法。具体农药品种包括,杀虫剂丙烯菊酯、氟氯氰菊酯、氯氰菊酯、溴氰菊酯、右旋苯醚菊酯、高效氯氟氰菊酯、二氯苯醚菊酯、除虫菊酯、苄呋菊酯、胺菊酯,增效剂增效醚和增效胺（octylbiclo heptene dicarboximide）。     

25%高效氯氟氰菊酯·啶虫脒乳油防治棉花蚜虫试验

试验比较了25%高效氯氟氰菊酯·啶虫脒乳油30g/hm2、60g/hm2、90g/hm2、25g/L高效氯氟氰菊酯乳油600g/hm2、20%啶虫脒可溶性粉剂150g/hm2等5种不同浓度和药剂对棉花蚜虫的田间防治效果。结果表明25%高效氯氟氰菊酯·啶虫脒乳油90g/hm2用量对棉花蚜虫速效性和持效性均较好。     

蜂蜜中氟胺氰菊酯残留量抽样调查

2002年通过对全国主要蜂蜜来源地中的10个省，1个直辖市地区，共124个蜂蜜样品进行抽样检测，共查出含氟胺氰菊酯残留样品7个，检出率5．6％，超过最大残留限量的样品为0个。监测结果表明，国内蜂蜜中氟胺氰菊酯的残留状况较好。     

氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆和土壤中的残留行为

建立了采用分散固相萃取法进行样品前处理,分别用液相色谱-质谱联用和气相色谱检测14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂中2种有效成分在豇豆和土壤中的残留量及消解动态的方法。结果表明:豇豆和土壤中分别添加0.005～1 mg/kg 4个水平的氯虫苯甲酰胺和高效氯氟氰菊酯,其平均回收率为80%～105%,相对标准偏差为0.70%～9.5%。北京和海南2地氯虫苯甲酰胺和高效氯氟氰菊酯在豇豆中的半衰期为4～6 d,土壤中的为10～24 d。成熟时采收,豇豆中氯虫苯甲酰胺和高效氯氟氰菊酯的残留量均低于0.2 mg/kg。推荐14%氯虫苯甲酰胺·高效氯氟氰菊酯微囊悬浮剂在豇豆上的使用剂量为有效成分45 g/hm2,使用方式为喷雾,施药次数不超过3次,施药间隔期为7 d,安全间隔期为5 d。     

基于叶绿素评价高效氯氟氰菊酯对三种农作物生态安全性

对大田栽培作物玉米、棉花、红薯和花生,用喷雾器喷施不同浓度杀虫剂高效氯氟氰菊酯,24h后测定4种作物叶绿素和类胡萝卜素的含量。结果表明,3 000倍高效氯氟氰菊酯对红薯和玉米是安全的,而高效氯氟氰菊酯对棉花则完全是有利的。     

利用酚醛环氧树脂-丙二胺聚合物制备高效氯氟氰菊酯微囊

探索了以酚醛环氧树脂-二元胺聚合物为壁材制备高效氯氟氰菊酯微囊(CS)的可行性,明确了酚醛环氧树脂用量及乳化剪切转速等因素对微囊基础物化特性以及药剂释放性能和应用效果的影响。利用油溶性单体酚醛环氧树脂与水溶性单体丙二胺,在油-水界面上发生聚合反应形成不溶于水的聚合物,制备得到高效氯氟氰菊酯微囊。通过光学显微镜和扫描电子显微镜观察其形貌;利用红外光谱仪分析囊壁结构;采用气相色谱法分析微囊的载药量、包封率和释放性能;经粒度分析仪测定平均粒径和粒度分布;最后采用浸叶法测定了该载药微囊的杀虫活性。结果表明:所得高效氯氟氰菊酯微囊为规则的球形,囊壁表面光滑无孔洞且伴有少量褶皱。随酚醛环氧树脂用量增加,微囊平均粒径增大,载药量下降,释放速率降低,而包封率变化不大。随乳化剪切转速增加,平均粒径下降,释放速率加快。采用优化条件制备所得微囊的平均粒径为21.33 μm,包封率为91.04%,载药量为43.97%。其释放动力学表现为:0~15 min内为快速释放阶段,累计释放量达到78.01%;15~240 min为缓慢释放阶段,在240 min时累积释放量达97.04%。4种不同粒径(2.78、5.19、11.86和23.15 μm)高效氯氟氰菊酯微囊和同剂量高效氯氟氰菊酯乳油对小地老虎幼虫的毒力测定结果表明:随着微囊粒径的减小,其毒力逐渐增大(LC50值分别为16.44、23.33、29.36和37.57 mg/L),但不同粒径微囊处理组毒力均略低于乳油(LC50值为10.41 mg/L)。研究表明,可采用酚醛环氧树脂-二元胺聚合物为壁材制备高效氯氟氰菊酯微囊,速效性好且活性易调控,在农药微囊剂制备中具有很好的应用前景。     

Encounter the poultry red mite resistance to acaricides in Czechoslovak poultry-farming

Poultry red mite susceptibility to permethrin, deltamethrin, tetramethrin, trichlorfon, fenitrothion, carbaryl and DDT, respectively, was screened within the territory of Bohemia by a method of diagnostic doses. The survey indicated widely spread resistance to DDT; in a few cases ineffectivity of permethrin, tetramethrin and trichlorfon, respectively, was also documented.     

Acute toxicity to zebrafish of two organophosphates and four pyrethroids and their binary mixtures

BACKGROUND: Environmental pollutants, including metals, pesticides and other organics, pose serious risks to many aquatic organisms. The acute toxicities to zebrafish (Brachydanio rerio Hamilton & Buchanan) were determined for two organophosphorus insecticides, four pyrethroid insecticides and 50:50 binary mixtures. RESULTS: At 24, 48, 72 and 96 h after treatment, LC₅₀ of permethrin, tetramethrin, bifenthrin, etofenprox, dichlorvos and phoxim to zebrafish were 0.0052–0.0025, 0.0782–0.0460, 0.0065–0.0032, 0.0969–0.0791, 51.3–13.0 and 1.28–0.469 mg L^?1 respectively. LC₅₀ of permethrin + dichlorvos, permethrin + phoxim, tetramethrin + dichlorvos, tetramethrin + phoxim, bifenthrin + dichlorvos, bifenthrin + phoxim, etofenprox + dichlorvos and etofenprox + phoxim were 0.0082–0.0046, 0.0078–0.0042, 0.264–0.124, 0.141–0.121, 0.0251–0.0154, 0.0154–0.0087, 0.396–0.217 and 0.213–0.0391 mg L^?1. CONCLUSION: Toxicity levels of all pyrethroid insecticides to the zebrafish were high or very high. The organophosphate dichlorvos showed low toxicity, but phoxim showed high or intermediate toxicities to zebrafish, and the toxicities of binary mixtures of permethrin and dichlorvos or phoxim, bifenthrin and dichlorvos or phoxim and etofenprox and phoxim (48, 72 and 96 h exposure) were very high. The toxicities of binary mixtures of tetramethrin and dichlorvos or phoxim, etofenprox and dichlorvos and etofenprox and phoxim (24 h exposure) were high. Copyright © 2009 Society of Chemical Industry     

Susceptibility to DDT and some other insecticides of head lice (Pediculus capitis De Geer) in Czechoslovakia

For testing the susceptibility of the head louse to insecticides impregnated bunches of polyamide fibres, whose diameter resembled that of human hair (0.1 mm) were used. In this manner a low mortality of control lice collected from infected persons was obtained (2.9% after 16 hours of exposure). Even after 25 years of DDT use no apparent resistance could be demonstrated in 25 tested louse populations and cross resistance to permethrin in 7 tested populations. The diagnostic concentration for resistance to pp'-DDT was established at 1%. Of the tested insecticides the highest toxicity was shown by malathion (LC50 = 0.000 018%), pirimiphos-methyl had on average a twice lower toxicity, trichlorphon 104 times lower, tetramethrin 1220 times lower, permethrin 2.5 times lower and pp'-DDT 630 times lower toxicity.     

The cross-resistance to pyrethrins and eight synthetic pyrethroids,of an organophosphorus-resistant strain of the rust-red flour beetle Tribolium castaneum (herbst)

Comparisons with standard susceptible insects showed that a strain of Tribolium castaneum, with a specific resistance to malathion and its carboxylic ester analogues, had no cross-resistance to topical applications of natural pyrethrins. Another strain of T. castaneum, showing resistance to many organophosphorus (OP) insecticides, was cross-resistant to pyrethrins ( × 34) and eight synthetic pyrethroids also applied topically; least cross-resistance occurred with resmethrin ( × 2.2), bioresmethrin ( × 3.3) and phenothrin ( × 4.0). Generally larger resistance factors were recorded with formulations synergised by piperonyl butoxide (PB). The greatest cross-resistance encountered was with unsynergised tetramethrin ( × 338). Apart from tetramethrin, factors of synergism did not exceed 5.7 with either the susceptible or multi-OP resistant strains. PB antagonised six of the nine pyrethroids against the multi-OP resistant strain. Antagonism also occurred with two of these six, permethrin (cis: trans ratio 1:3) and 5-prop-2-ynylfurfuryl ( 1RS)-cis,trans-chrysanthemate (‘Prothrin’), against the susceptible strain. Considering only formulations without the synergist, the most effective compounds against the susceptible strain, relative to pyrethrins, were bioresmethrin (2.7) and permethrin (2.4). Similarly with the multi-OP resistant strain the most effective compounds were bioresmethrin (28), resmethrin (14) and permethrin (6.6). Thus the LD₅₀ (the dose required to kill 50% of the test species) for bioresmethrin against the resistant strain (0.14 μg) only slightly exceeded the LD₅₀ for pyrethrins against the susceptible strain (0.12 μg).     

Efficacy of selected pesticides against synanthropic mites under laboratory assay

BACKGROUND: The efficacies of organophosphate pesticides, single‐compound versus multicompound pyrethroid formulations and relatively novel unclassified insecticides/acaricides were compared to find the lowest dosage and highest efficacy for the control of Dermatophagoides farina (Hughes), D. pteronyssinus (Trouessart) and Tyrophagus putrescentiae (Schrank). Formulated active ingredients (AIs) were diluted in water and applied onto filter paper in experimental chambers with ten unsexed adult mites in six replicates. Mite mortality was checked after 24 h. The security index (SI) was calculated for all of the AIs by dividing the recommended rate by the LD₉₀ determined for each species. RESULTS: The tested organophosphates had high LD₉₀ and low SI values. The single‐compound pyrethroids were ineffective (deltamethrin and beta‐cyfluthrin) or had high LD₉₀ and low SI values (cyphenothrin, permethrin, pyrethrum and bifenthrin). The multicompound miticides had low LD₉₀ and high SI values which increased from deltamethrin/S‐bioallethrin to permethrin/S‐bioallethrin/piperonyl butoxide to permethrin/pyriproxyfen/benzyl benzoate. Abamectin, pyridaben, propargite and flufenoxuron were highly active against Dermatophagoides spp. Neem (Acarosan duo) was highly active against all mite species tested. CONCLUSION: The available formulations of multicompound pyrethroids (permethrin/S‐bioallethrin/piperonyl butoxide, permethrin/pyriproxyfen/benzyl benzoate), benzyl benzoate, neem and some field acaricides are effective in suppression of synanthropic mites in laboratory assays. Their LD₉₀ are lower than those of traditionally used organophosphates or single‐compound pyrethroid formulations. Copyright © 2011 Society of Chemical Industry     

Cytochrome P450 monooxygenase-mediated permethrin resistance confers limited and larval specific cross-resistance in the southern house mosquito, Culex pipiens quinquefasciatus

The cytochrome P450-dependent monooxygenases (P450s) are an important enzymatic system that metabolizes xenobiotics (e.g., pesticides), as well as endogenous compounds (e.g., hormones). P450-mediated metabolism can result in detoxification of insecticides such as pyrethroids, or can be involved in the bioactivation and detoxification of insecticides such as organophosphates. We isolated (from the JPAL strain) a permethrin resistant strain (ISOP450) of Culex pipiens quinquefasciatus, having 1300-fold permethrin resistance using standard backcrossing procedures. ISOP450 is highly related to the susceptible lab strain (SLAB) and the high resistance to permethrin is due solely to P450-mediated detoxification. This is the first time in mosquitoes that P450 monooxygenase involvement in pyrethroid resistance has been isolated and studied without the confounding effects of kdr. Resistance in ISOP450 is incompletely dominant (D = +0.3), autosomally linked, and monofactorally inherited. It is expressed in the larvae, but not in adults. Cross-resistance to pyrethroids lacking a 3-phenoxybenzyl moiety (tetramethrin, fenfluthrin, bioallethrin, and bifenthrin) ranged from 1.5- to 12-fold. ISOP450 had only limited (6.6- and 11-fold) cross-resistance to 3-phenoxybenzyl pyrethroids with an α-cyano group (cypermethrin and deltamethrin, respectively). Examination of cross-resistance patterns to organophosphate insecticides in ISOP450 showed an 8-fold resistance to fenitrothion, while low, but significant, levels of negative cross-resistance were found for malathion (RR = 0.84), temephos (RR = 0.73), and methyl-parathion (RR = 0.55). The importance and uniqueness of this P450 mechanism in insecticide resistance is discussed.     

Metabolism of tetramethrin in houseflies in vivo

Houseflies susceptible to pyrethroids were found to metabolize in vivo radioactive tetramethrin (phthalthrin) or 3,4,5,6-tetrahydrophthalimidomethyl dl-trans chrysanthemumate mainly to N-(hydroxymethyl) 3,4,5,6-tetrahydrophthalimide and chrysanthemumic acid. Smaller amounts of oxidation products of tetramethrin or chrysanthemumic acid were formed. Pretreatment with piperonyl butoxide had little effect on the cleavage of the ester bond of tetramethrin, but another synergist NIA 16388 remarkably inhibited this reaction.     

Studies with permethrin against bodylice in Egypt

Approximately 350 people, the inhabitants of two villages in the Fayum district of Egypt, were individually dusted with 50 g of powder containing 2.5 or 5.0 g permethrin kg^?1. The inhabitants of a third village were left untreated as a control. Before treatment, approximately two-thirds of the population of all three villages were infested with bodylice. Fourteen days after treatment, the permethrin dust at the lower strength reduced the infestation by 98.8% and at the higher strength by 100%. The dust containing 5 g permethrin kg^?1 maintained a high level of residual control (80.5%) for at least 91 days. The other gave a lower level of control at this time. Urine samples, taken from subjects in each of the treated villages before and after dusting, were analysed for permethrin metabolites. Results indicated that the maximum amount of permethrin absorbed, orally, through the skin, or by inhalation, was 39 μg kg^?1 body weight, 24 h after treatment. No residue was found 30 days and 60 days after treatment. It was concluded that there was a very substantial safety margin when permethrin dusts were used on man for bodylice control.     

Action of pyrethroids on a nerve-muscle preparation of the clawed frog,Xenopus laevis

The effects of a range of pyrethroids on end-plate potentials and muscle action potentials were studied in the pectoralis nerve-muscle preparation of the clawed frog, Xenopus laevis. The noncyano pyrethroids allethrin, cismethrin, bioresmethrin, and IR-cisphenothrin caused moderate presynaptic repetitive activity only, resulting in the occurrence of multiple end-plate potentials (epps). Trains of repetitive muscle action potentials without presynaptic repetitive activity were observed after the α-ethynyl pyrethroid S-5655 and after the α-cyano pyrethroids cypermethrin, deltamethrin, FCR 1272, and FCR 2769. An intermediate group of pyrethroids consisting of the non-cyano compounds 1R-permethrin, des-cyano-deltamethrin, NAK 1901 and NAK 1963, and the α-cyano pyrethroids cyphenothrin and fenvalerate caused both types of effect. The insecticidally inactive S-enantiomers of permethrin had no effect on the nerve-muscle preparation. Trains of repetitive action potentials in pyrethroid-treated muscle fibers were followed by a depolarizing afterpotential which in general decayed more rapidly for the non-cyano pyrethroids than for the α-cyano pyrethroids. The rate of decay of the depolarizing afterpotential decreased gradually as the temperature was lowered, whereas the pre- and postsynaptic repetitive activity remained largely unaffected over a large temperature range. It is concluded that in muscle membrane like in nerve membrane the pyrethroid-induced repetitive activity is due to a prolongation of the sodium current and that a clear distinction between non-cyano pyrethroids on the one hand and α-cyano compounds on the other cannot be made on the basis of the present results.     

营养和农药对蜡蚧轮枝菌生长发育的影响

在25℃条件下,测定了4种培养基和8种农药对蜡蚧轮枝菌生长发育的影响。结果表明,马铃薯葡萄糖和查氏培养基最适于菌丝生长和产生分生孢子。所有供试农药对蜡蚧轮枝菌菌丝生长均有显著的抑制作用,其中代森锰锌的抑菌率高达100%,其次为代森锌、百菌清及敌敌畏,再次为氯氰菊酯和阿维柴油,链霉素和氟虫腈的抑菌率最低。