A new aqueous suspension concentrate formulation of cis‐permethrin and its insecticidal activity

Isomers of pyrethroids usually have different insecticidal activities. Permethrin, a non‐cyano pyrethroid, is not an exception and cis‐permethrin is much more active than the trans‐isomer against Triatoma infestans, vector of Chagas' Disease in Argentina. The large‐scale separation of cis‐ and trans‐permethrin was performed by successive recrystallizations from ethanol‐water mixtures. An aqueous suspension concentrate (flowable) formulation of pure crystalline cis‐permethrin was prepared and assayed for its insecticidal activity on wood and ceramic surfaces against nymph V of T infestans. This formulation was at least three times more effective than deltamethrin, with LC₅₀ values on ceramic of 0.11 µg cm⁻² and 0.33 µg cm⁻² respectively. On wood surfaces, the LC₅₀ value was 0.57 µg cm⁻² compared with 3.20 µg cm⁻² for deltamethrin. Against other insect species such as Periplaneta americana, Aedes aegypti and Culex quinquefasciatus, the suspension concentrate formulation of cis‐permethrin was, however, less effective than similar formulations of deltamethrin or β‐cypermethrin. © 2000 Society of Chemical Industry     

Effect of substituents at the 5-position of the pyridine ring of imidacloprid on insecticidal activity against Periplaneta americana

The insecticidal activities of imidacloprid derivatives with a wide range of substituents at the 5-position on the pyridine ring against American cockroaches, Periplaneta americana (L.), were measured by injection with and without synergists propyl 2-propynyl phenylphosphonate and piperonyl butoxide. The log(1/MLD) value (MLD = minimal lethal dose in mol) without synergists was 7.96 for the methyl derivative, and the values were lower for other derivatives. Synergists enhanced the potencies of all the compounds tested. Considering these compounds and those with other substituents at this position, the region for maximum activity was predicted to be in the conjunction of the pyridyl 6-chlorine atom with a lipophilic small group in the 5-position.     

Synthesis and insecticidal activity of new amide derivatives of piperine

The natural lipophilic amides piperine and piperiline were isolated from Piper nigrum L (Piperaceae). Piperine was hydrolysed into piperic acid (85% yield) which was converted into 16 amides (28–89% yield). The contact toxicity of all synthetic amides, and also that of piperine and piperiline, at the dose 10 µg per insect, was evaluated for the Brazilian economically important insects Ascia monuste orseis Latr, Acanthoscelides obtectus Say, Brevicoryne brassicae L, Protopolybia exigua DeSaus and Cornitermes cumulans Kollar. The results demontrated that the insects have different sensivities to the various amides, with mortality ranging from 0 to 97.5% according to the compound and insect species. © 2000 Society of Chemical Industry     

Synthesis and insecticidal activities of novel oxime ether pyrethroids

A series of novel 2-methylthio-3'/4'-substituted acetophenone oxime O-ethers were synthesized by the reaction of the corresponding acetophenone oximes with halides of pyrethroid alcohols in the presence of sodium hydroxide and phase-transfer catalysis or with triethyl quaternary ammonium salts of halides of pyrethroid alcohols in the presence of sodium hydroxide. These compounds showed notable insecticidal activity against Homopteran and Lepidopteran pests. 2-Methylthio-4'-fluoroacetophenone oxime O-[(2-methylbiphenyl-3-yl)methyl] ether was more effective than the commercial insecticides chlorfenapyr and fenvalerate.     

含单氟甲氧基的双酰胺类化合物的合成及杀虫活性

以2,3-二氯吡啶为起始原料,经肼基化、环合、氧化、取代、水解、环合和胺解反应,合成了15个文献未见报道的新型含单氟甲氧基的吡唑邻甲酰氨基苯甲酰胺类化合物,其结构通过核磁共振氢谱和高分辨质谱确认。初步的杀虫活性测试结果显示,所有目标化合物在100 mg/L下对粘虫Oriental armyworm的致死率均为100%,当测试浓度降低至4 mg/L时,化合物 8a 、 8d 、 8g 、 8k 和 8n 的致死率仍为100%,值得进一步研究。     

二氢吡唑邻甲酰氨基苯甲酰胺衍生物的合成及杀虫活性

以邻氨基苯甲酸和4,5-二氢吡唑-5-甲酸为原料,制备得到苯并噁嗪酮,所得产物与取代胺作用制得8个结构新颖的二氢吡唑邻甲酰胺基苯甲酰胺类化合物,其结构用核磁共振氢谱和质谱进行了表征。生物活性试验结果表明,在500 mg/L质量浓度下,部分化合物对小菜蛾Plutella xylostella、苜蓿蚜Aphis medicaginis和稻飞虱Nilaparvata lugens的致死率达100%。     

Synthesis and insecticidal activity of nitroguanidine derivatives

Nitroguanidine derivatives with thiazol-5-ylmethyl moieties were prepared and their insecticidal activities against homopterous pests were tested. New synthetic routes for 2-chloro-5-chloromethylthiazole from 2,3-dichloro-1-propene and for substituted nitroguanidines from S-methyl-N-nitroisothiourea were established. Biological evaluation led to a novel insecticide (E)-1-(2-chlorothiazol-5-ylmethyl)-3-methyl-2-nitroguani dine (TI-435) which has a broad activity spectrum and is under development. ©1999 Society of Chemical Industry     

嘧啶酮类衍生物的合成及杀虫活性

为了创制高效广谱的绿色杀虫剂,以(E)-4,5-二氢-6-甲基-4-(3-吡啶亚甲基氨基)-1,2,4-三嗪-3(2H)-酮(吡蚜酮)为先导,用带有不同电荷密度的五元、六元取代苯环或杂环取代其结构中的吡啶环部分,合成了10个全新的嘧啶酮类衍生物,特别对其中所包含的三嗪环和二氢喹唑啉酮合成部分进行了重点研究。所有目标化合物的结构均经过核磁共振氢谱、高分辨质谱及红外光谱的确认。初步杀虫活性测试结果表明,目标化合物对蚜虫Aphis craccivora未表现出明显的杀虫活性,初步暗示了先导化合物吡蚜酮结构中所含的吡啶环部分可能对其杀虫活性起了重要作用。     

海南普通大蓟马对拟除虫菊酯药剂抗性监测及钠通道突变检测

普通大蓟马Megalurothrips usitatus在海南省对豇豆造成严重危害且抗药性逐渐增强。本研究测定了2019年至2021年海南省普通大蓟马对氯菊酯和甲氰菊酯的抗性。结果表明,海口、乐东和三亚3个地理种群对甲氰菊酯处于极高水平抗性,对氯菊酯处于高水平抗性,且抗性逐年增强。对普通大蓟马钠离子通道序列分析发现存在M283R突变,该突变位于钠离子通道同源结构域Ⅰ。突变频率检测显示,2019年至2021年连续3年海口种群该突变位点的突变频率分别为1/30、1/30、3/30,有升高趋势。本研究发现海南省普通大蓟马从2019年到2021年对拟除虫菊酯类药剂的抗药性呈逐年上升趋势。     

含三氟甲基异噁唑啉类化合物的合成及杀虫活性

以取代α-三氟甲基苯乙烯和取代的肉桂醛肟为原料,经过1,3-偶极环加成反应,合成了16个未见文献报道的含三氟甲基异噁唑啉结构的目标化合物,其结构经1H NMR和LC-MS确认。初步杀虫活性测试结果表明:在500 mg/L下,大部分目标化合物对斜纹夜蛾Prodenia litura和粘虫Mythimna sepatara具有一定的杀虫活性,其中ZJ11对粘虫的致死率达100%,即使在100 mg/L下,其致死率仍达80%。     

Thermal behaviour and biological activity of pyrethroids in smoke-generating formulations

Smoke-generating insecticide formulations are nowadays very important for the control of Chagas' disease vectors. In this work, the thermal decomposition of different pyrethroid insecticides in smoke-generating formulations has been studied. Their recovery from the smoke has been determined, and the effect on this of the addition of foaming agents such as cyanoguanidine (CNG) or azodicarbonamide (ADC), or antioxidant agents such as butylated hydroxytoluene (BHT) or butylated hydroxyanisole (BHA) has been assessed. In each case the best smoke-generating formulation was established. Calorimetric studies were done to justify the behaviour of the smoke-generating mixtures. The isomerization process for different pyrethroids was also studied, to establish the influence of the foaming agents in inhibiting isomerization to less active pyrethroids. Smoke-generating mixtures containing β-cypermethrin and cis-permethrin as insecticides and CNG or ADC as foaming agents were evaluated for their insecticidal activity against nymphs I of Triatoma infestans, vector of Chagas' disease. The best effect was found with β-cypermethrin formulated with ADC, with LT₅₀ values lower than 5 min. © 1999 Society of Chemical Industry     

新型氯虫苯甲酰胺衍生物的合成及其杀虫活性

以氯虫苯甲酰胺为先导,设计并合成了一系列结构新颖的邻氨基苯甲酰胺类衍生物,其结构均经核磁共振氢谱和质谱确证。初步杀虫活性测试结果表明,在质量浓度为1μg/mL时,部分化合物对小菜蛾Plutella xylostella的致死率均超过90%,高于先导化合物氯虫苯甲酰胺。     

Synthesis and insecticidal evaluation of N-substituted 2-nitroiminoimidazolidines

N-substituted and N,N′-disubstituted 2-nitroiminoimidazolidines were prepared from 2-nitroiminoimidazoline. The feeding-contact and systemic activities as insecticides of some of these new compounds have been evaluated. © 1998 Society of Chemical Industry     

Synthesis and insecticidal activities of unsymmetrical bis-arylalkyl ketones. A new structural concept in pyrethroids

Seventeen unsymmetrical bis-arylalkyl ketones were synthesised and their insecticidal activities against Musca domestica, Locusta migratoria, Drosophila melanogaster, Dysdercus cingulatus, Aedes aegypti and Tetranychus urticae were tested. The synergistic effect of piperonyl butoxide on the activities of some of the new ketopyrethroids against Musca domestica was also determined. Several structural variations, including substituent exchange in the aryl moieties, the position of the ketone function and increase or decrease of the length of the carbon chain connecting the two aryl moieties, were made in order to examine the structure-activity relationship. All biological activities were compared with the activity of the ether pyrethroid 2-(4-ethoxyphenyl)-2-methylpropyl 3-phenoxybenzyl ether (MTI-500).     

Quantitative structure—activity studies of some octopaminergic agonists against Periplaneta americana

The quantitative relationship between the structure of 2-(arylimino) thiazolidines (AITs), arylethanolamines (AEAs) and 2-(arylalkylamino)-2-thi-azolines (AATs) and their octopamine (OA)-agonist activities against the ventral nerve cord of American cockroach, Periplaneta americana L., was analysed using reported physicochemical parameters and regression analysis. The electronic nature of a substituent was the most important factor for AAT, followed by the hydrophobic effects: the more electron-donating and the more hydrophobic the substituent, the greater the activity. The hydrophobic nature of a substituent in AEA was the most important factor, followed by the steric effects: the more hydrophobic the substituent, the greater the activity. The more electron-donating the substituent of AIT, the greater the activity.