新烟碱类杀虫剂选择作用的分子机理

新烟碱类是一类重要的新颖杀虫剂,其发现是近20年来杀虫剂研究的一个里程碑。烟碱类和新烟碱类杀虫剂虽然都是作为后突触烟碱乙酰胆碱受体(nAChRs)的激动剂作用于昆虫的神经系统,但由于作用方式不同,新烟碱类杀虫剂对昆虫表现出选择性毒性。根据烟碱类和新烟碱类杀虫剂结构与活性的关系、分子特性以及它们与nAChR的结合部位和亚部位的选择性阐释了新烟碱类杀虫剂选择作用的分子机理。     

杀虫剂的作用方式与分类

随着杀虫剂产品的逐渐增多,按照其作用方式进行分类显得十分重要,不仅有利于新化合物的合成与筛选,而且有助于了解其抗药性以及科学地使用。本文收集了杀虫剂(杀螨剂)共253种,分属19种不同的作用方式和60种不同的化合物类别。     

评价杀虫剂混用联合作用的六种方法比较

本文介绍了六种评价杀虫剂混用对昆虫联合作用的方法即三角坐标法，Ｂｌｉｓｓ法，Ｍａｎｓｏｕｒ法，Ｓｕｎ法，πｏｎｏＢ法和Ｆｉｎｎｅｙ法，同时在室内条件下测定了硫双灭多威（ｔｈｉｏｄｉｃａｒｂ）与溴氰菊酯（ｄｅｌｔａｍｅｔｈｒｉｎ）和甲基对硫磷（ｐａｒａｔｈｉｏｎｍｅｔｈｙｌ）混用后对稻黑毛叶蝉（Ｎｅｐｈｏｔｅｔｔｉｘｃｉｎｃｔｅｉｃｅｐｓ（Ｕｈｌｅｒ）４龄若虫的联合毒力作用，结果表明，无论采用何种方     

三种增效剂对棉铃虫增效作用

用３个不同地区的棉铃虫田间种群分别测定了３种增效剂对３种杀虫剂的增效作用。结果表明ＰＢ对氯氟氰菊酯,ＤＥＦ对辛硫磷,ＰＢ和ＴＰＰ对灭多威增效较好,而且棉铃虫的抗性水平越高,增效剂的增效作用越突出。     

Aerial Application of Insecticides for the Control of the Mango-Hopper

Abstract

Aerial application of malathion LVC at 893 and 1330 g/ha, malathion EC at 927 g/ha, carbaryl SP at 557, 841 and 1113 g/ha, and endosulfan ec at 432 and 649 g/ha was tested for the control of mango-hopper at 8 places in Hoshiarpur and Ropar districts of the Punjab using a fixed-wing aircraft for spraying in the end of February. The penetration of spray material through the deep canopy of seedling mango trees was good. There was 86–100% reduction in the pest population over control 9 days after treatment. Malathion LVC at 1330 g/ha proved to be the best. It gave an excellent knock-down and did not register any significant build-up in the mango-hopper population up to 51 days after spraying.     

重组杆状病毒杀虫剂的研究进展

本文从基因缺失、基因插入、改变宿主范围3个方面系统的介绍了杆状病毒杀虫剂的研究进展。     

Actions of Tefluthrin on Rat Na(v)1.7 Voltage-Gated Sodium Channels Expressed in Xenopus Oocytes

In rats expression of the Na_v1.7 voltage-gated sodium channel isoform is restricted to the peripheral nervous system and is abundant in the sensory neurons of the dorsal root ganglion. We expressed the rat Na_v1.7 sodium channel α subunit together with the rat auxiliary β1 and β2 subunits in Xenopus laevis oocytes and assessed the effects of the pyrethroid insecticide tefluthrin on the expressed currents using the two-electrode voltage clamp method. Tefluthrin at 100 μM modified of Na_v1.7 channels to prolong inactivation of the peak current during a depolarizing pulse, resulting in a marked “late current” at the end of a 40 ms depolarization, and induced a sodium tail current following repolarization. Tefluthrin modification was enhanced up to twofold by the application of a train of up to 100 5 ms depolarizing prepulses. These effects of tefluthrin on Na_v1.7 channels were qualitatively similar to its effects on rat Na_v1.2, Na_v1.3 and Na_v1.6 channels assayed previously under identical conditions. However, Na_v1.7 sodium channels were distinguished by their low sensitivity to modification by tefluthrin, especially compared to Na_v1.3 and Na_v1.6 channels. It is likely that Na_v1.7 channels contribute significantly to the tetrodotoxin-sensitive, pyrethroid-resistant current found in cultured dorsal root ganglion neurons. We aligned the complete amino acid sequences of four pyrethroid-sensitive isoforms (house fly Vssc1; rat Na_v1.3, Na_v1.6 and Na_v1.8) and two pyrethroid-resistant isoforms (rat Na_v1.2 and Na_v1.7) and found only a single site, located in transmembrane segment 6 of homology domain I, at which the amino acid sequence was conserved among all four sensitive isoform sequences but differed in the two resistant isoform sequences. This position, corresponding to Val410 of the house fly Vssc1 sequence, also aligns with sites of multiple amino acid substitutions identified in the sodium channel sequences of pyrethroid-resistant insect populations. These results implicate this single amino acid polymorphism in transmembrane segment 6 of sodium channel homology domain I as a determinant of the differential pyrethroid sensitivity of rat sodium channel isoforms.     

杀虫剂对赤眼蜂的影响

综述杀虫剂对赤眼蜂影响的测定方法、结果及影响因子,以及赤眼蜂的抗药性筛选方法和结果,并对今后有关研究提出了建议。     

拟除虫菊酯类农药酶免疫分析方法研究进展

对拟除虫菊酯类单一农药残留和多残留酶免疫分析方法的研究进展进行了综述。在介绍单一农药残留酶免疫分析方法中半抗原分子设计和ELISA方法建立的基础上,指出刚性连接臂是菊酯类农药免疫半抗原分子设计的一般原则,包被原和免疫原采用不同的载体蛋白和不同结构的半抗原有利于菊酯类农药ELISA方法的建立。在介绍菊酯类农药多残留酶免疫分析方法时,剖析了通用免疫半抗原的结构特点,阐述了宽谱特异性抗体的筛选方法,揭示了在菊酯类农药多残留酶免疫分析法中存在竞争半抗原的选择具有盲目性、宽谱特异性抗体对不同农药的特异性差异较大的问题。并对拟除虫菊酯类农药通用免疫半抗原设计及多残留酶免疫分析技术的发展趋势进行了探讨。     

A Rapid Method for Screening Insecticides in the Laboratory

An efficient method for rapidly mass-screening insecticides for use against sap-feeding virus vectors is presented with a case study of 30 chemicals. The method permits large numbers of insecticides to be tested simultaneously and relatively inexpensively in a sequence of laboratory bioassays. The sequence is designed to find the most effective pesticide at the lowest concentration giving control without phytotoxicity. The system was derived to test candidate insecticides to control tomato yellow leaf curl virus vectored by the tobacco whitefly, Bemisia tabaci Gennad., the most serious pest of greenhouse and field tomatoes in the Middle East. Although the insecticides were all more efficacious in the laboratory than in the field, bioassay results were highly correlated with results from field trials, giving high confidence that the screening process selected only the most efficacious insecticides. Most of the insecticides accepted by the screening process have since been adopted by vegetable growers in Israel. The method is not intended to eliminate field efficacy trials, but to reduce the number of trials and treatments that need to be performed, thereby reducing costs. The method provides for the optimization of application rates which will contribute to the expected life of insecticides before resistance develops, and will also help to reduce environmental contamination. In addition, the method is suitable for estimating relative efficacy for pesticide benefits assessments, a required part of the (re-)registration process for pesticides in some countries. Although developed for screening insecticides against virus-transmitting sap-feeding insects, the method could be modified to assess the efficacy of insecticides in controlling other insect pests.     

几种杀虫剂对亚非玛草蛉的毒力

采用药膜法测定了高毒农药替代品的6种药剂对柑桔害虫重要捕食性天敌亚非玛草蛉Mallada desjardinsi的毒力作用。结果表明,6种药剂对亚非玛草蛉的毒力大小依次为毒死蜱〉氧化乐果〉丁硫克百威〉高效氯氟氰菊酯〉阿维菌素〉印楝素。其中前5种药剂的LC95分别为18.67、324.48、1694.80、11520.83、642592.76mg/L;LC50分别为8.20、41.03、134.85、527.89、7799.57mg/L。印楝素对亚非玛草蛉的毒性极小,其LC50和LC95因毒力低而未测出。     

粉虱类害虫抗药性研究方法综述

粉虱是世界上一类重要的害虫,随着化学杀虫剂的连续使用,其抗药性也日益严重。本文对粉虱类害虫的抗药性监测、机理及风险评估方法进行了综述,旨在对粉虱抗药性工作能提供一定的帮助。     

几种药剂混配防治西兰花根部病害综合效果试验

为了有效防治西兰花根肿病、根腐病、根结线虫病等根部病害,提升西兰花的产量和品质,采用灌根法进行几种药剂混配防治西兰花根部病害田间药效试验,结果表明:6 8%精甲霜锰锌WG 500倍+3.2%阿维菌素EC 1 000倍+微补精力600倍+微补根力钙600倍对西兰花根部病害具有较好的综合防治效果,其中连续2次灌根后50 d的校正防效达82.1%,分别比68%精甲霜锰锌WG 500倍+3.2%阿维菌素EC 1 000倍、5%石灰氮GR 1 200 kg/hm2高出5.6%、21.3%,持效期较长,安全性好,因此可以在生产上加以推广应用。     

新型杀虫剂氰氟虫腙的合成技术

合成新型杀虫剂氰氟虫腙。以4-三氟甲氧基苯胺为原料,经过三步反应,合成了氰氟虫腙。所合成的目标产物的纯度超过了99.2%,总收率达到95.9%,产物结构经IR,1H NMR确证。该方法原料低毒易得,操作简单,条件温和,适用于工业化生产。     

杀虫剂分子靶标烟碱型乙酰胆碱受体研究进展

昆虫烟碱型乙酰胆碱受体(nicotinic acetylcholine receptors,nAChRs)广泛分布于昆虫中枢神经系统,是杀虫剂作用的主要靶标。目前昆虫中该受体的天然亚基组成尚不完全明确。果蝇的任意α亚基与脊椎动物的一个β亚基共表达是目前最好的异源表达模型,但仍然急需新的研究工具,研究表明一些与受体相关的蛋白质影响着表达。胞内磷酸化的调节作用为今后受体药理学特性的研究提供了新方向。受体亚基上一些关键氨基酸在新烟碱杀虫剂对受体的选择作用中起重要作用。在对吡虫啉抗性的褐飞虱种群中找到了与抗性相关的突变位点,这为新烟碱类杀虫剂靶标不敏感性研究提供了直接证据。对昆虫烟碱型乙酰胆碱受体的分子多样性、功能表达、胞内调节机制、受体与杀虫剂的选择作用及其抗性分子机理等的研究进展进行了综述。     

吡唑类、吡咯类杀虫剂的研发进展

本文对吡唑类、吡咯类杀虫剂的开发现状及应用前景进行了简要的介绍。文中涉及吡唑类、吡咯类杀虫剂的化学结构、生物活性、登记与专利和开发公司等。     

双酰胺类杀虫剂环境风险问题浅析

双酰胺类杀虫剂是一类优势明显的新型杀虫剂,防效卓越,持效期长,且与传统农药无交互抗性。然而,这类高生物活性杀虫剂的缺点也很明显:对环境中特定种类的非靶标生物毒性很高,在环境介质中的残留期很长,对生态系统的潜在风险较高。本文综述了双酰胺类杀虫剂的主要品种及其作用特点,国内外登记情况,及其对环境生物的生态毒理学研究进展等。双酰胺类杀虫剂对水生无脊椎动物、家蚕的潜在风险,乃至脊椎动物(鸟类、鱼类)的慢性风险均有待进一步开展深入研究与评估。同时,今后应继续加强双酰胺类农药使用后的环境风险监测,在发挥杀虫优势的同时避免或减少其对生态环境的污染和破坏。     

甲氨基阿维菌素苯甲酸盐等5种化学药剂对薄荷金叶甲的毒力效果研究

为科学有效地防治丹参新害虫--薄荷金叶甲,本文测定了5种化学药剂啶虫脒、噻虫嗪、阿维菌素、甲氨基阿维菌素苯甲酸盐、高效氯氰菊酯对丹参新害虫薄荷金叶甲的毒力效果。结果表明,所选5种化学药剂对薄荷金叶甲均有一定的毒力作用,但相互之间存在较大差异,其中,甲氨基阿维菌素苯甲酸盐的毒力最高,LC50值为1.7404mg/L,啶虫脒和高效氯氰菊酯的毒力相近,LC50值分别为64.7845和86.5744mg/L,而噻虫嗪对薄荷金叶甲的毒力较差,LC50值为220.2474 mg/L,阿维菌素对薄荷金叶甲的毒力最差,LC50值为678.6936mg/L。     

13种杀虫剂对暗黑蛴螬的毒力研究

本文采用灌注处理法测定了7种常用杀虫单剂及6种杀虫混剂对暗黑鳃金龟甲2龄幼虫的室内毒力。结果表明：7种单剂对暗黑蛴螬的毒力顺序为：甲基异柳磷＞对硫磷＞甲基对硫磷＞二嗪磷＞辛硫磷＞乐斯本＞＞敌百虫；6种混剂中以辛硫磷＋对硫磷表现毒力最高，而甲基对硫磷＋敌百虫表现毒力最低。联合毒力测定结果表明：辛硫磷＋对硫磷及辛硫磷＋敌百虫表现为显著增效，甲基对硫磷＋敌百虫表现为相加作用，其它3种混剂均表现为轻度增效。     

根区施药试验研究的新进展

本文就继续研究应用呋喃丹、杀虫脒、巴丹类等内吸杀虫剂根区施用的十种不同方式防治水稻三化螟、稻瘿蚊、稻蓟马、稻纵卷叶螟、褐稻虱等主要害虫的药效及对害虫天敌影响的新进展作扼要的报道,进一步阐明根区施药的科学根据、盆栽及田间试验结果、以及指出应用楝科植物(印楝、川楝、苦楝)对稻瘿蚊等害虫防治的可能性和探索呋喃丹根区施用对褐稻虱的杀卵作用。此外,对湖北、江西等地约10万余亩稻田推广根区施药试验示范的情况亦作适当的介绍。