印楝杀虫剂的杀虫作用和机理

印楝杀虫剂的杀虫作用和机理钟平（中国─—欧共体农业技术中心北京１０００２６）使用化学杀虫剂引起的害虫抗药性和农药残留，污染农产品和环境的问题已受到世界各国的广泛关注。为寻找化学杀虫剂的替代品，近年各国积极开展对植物杀虫剂的研究。楝科植物中的印楝（Ａｚ...     

植物性杀虫剂印楝的研究进展

对植物性杀虫剂印楝的研究正在向两个方向发展, 一是深入到分子毒理水平, 进行结构与活性关系的研究; 另一方面是研究其在害虫防治中的应用。文章就目前印楝制剂的使用技术研究状况作了评述。由于植物性杀虫剂在作用方式和作用机制上与有机合成杀虫剂有一定的差别, 对害虫的作用靶标有所不同, 因此, 在剂型和药剂分散体系的设计上也有所不同,对这些相关领域进行深入研究, 将能更有效地发挥包括印楝在内的植物性杀虫剂在田间的使用效果, 是植物性杀虫剂研究中一个非常重要的内容。     

印楝杀虫作用机理

印楝素能降低昆虫的血细胞数量、血淋巴蛋白质含量、血淋巴海藻糖和金属阳离子浓度、脂肪体中DNA和RNA含量,抑制昆虫中肠酯酶和脂肪体中蛋白酶、淀粉酶、脂肪酶、磷酸酶和葡萄糖酶的活性,降低昆虫的取食率和对食物的转化利用率,影响昆虫的正常呼吸节律,降低昆虫雌虫卵巢、输卵管、受精囊中蛋白质、糖原和脂类的含量及一些酶的活性,对雄虫生殖系统有影响,使昆虫的脑、咽侧体、心侧体、前胸腺、脂肪体等发生病变,影响昆虫体内激素平衡,从而干扰昆虫生长发育。     

印楝素对小麦蚜虫的防治效果和应用技术

田间药效试验表明,1.2%印楝素乳油对小麦蚜虫的防治效果好。每667 m2用63~83 mL,药后3 d、7 d、10 d和15 d,对小麦蚜虫的防治效果分别在63.35%~80.14%、74.99%~93.33%、74.42%~93.15%和73.61%~92.99%。该药剂速效性较差,持效性好,药效持续时间长,在全国小麦产区均可作为防治小麦蚜虫的有效药剂,替代化学农药进行推广使用。     

蔬菜油与印楝素乳油混配对菜青虫的防治效果

将棉籽油与地沟油按1∶1比例混合,配制成基础油,然后添加5%乳化剂制成95%蔬菜油杀虫剂,再将该蔬菜油杀虫剂与0.7%印楝素乳油按1∶1比例配制成混配剂,对菜青虫进行防治试验。结果表明,每667 m~2用蔬菜油与印楝素混配剂60 mL对菜青虫的防治效果略优于对照药剂每667 m~2用0.7%印楝素乳油40 mL。每667 m~2用蔬菜油与印楝素混配剂80 mL对菜青虫的防治效果显著高于对照药剂每667 m~2用0.7%印楝素乳油40 mL。     

0．3％印楝素防治稻纵卷叶螟试验

0．3％印楝素是云南中科生物产业有限公司生产的防治稻纵卷叶螟的新型杀虫剂．为验证其防治效果和为推广应用提供依据．笔者于2008年用该药剂对稻纵卷叶螟进行了药剂防治试验。     

0.3%印楝素乳油防治高粱条螟药效试验

高粱是酒都仁怀市的支柱产业,近年来随着高粱种植面积的不断扩大,高粱条螟在高粱产区的为害呈加重趋势。为验证有机认证生物农药0.3%印楝素乳油对高粱条螟的防治效果,我们于2010年用0.3%印楝素乳油对高粱条螟进行了田间药效试验。     

印楝素A和印楝素B生物活性比较

对印楝素A和印楝素B的生物活性进行了研究。在3μg/mL的剂量下处理后24 h,印楝素A和印楝素B对小菜蛾3龄幼虫的拒食率分别为85.3%和80.4%;在5μg/mL的剂量下处理后24 h,对棉铃虫3龄幼虫的拒食率分别为94.9%和80.2%。处理后72 h,印楝素A和印楝素B对斜纹夜蛾3龄幼虫的LC₅₀分别为1.0μg/mL和3.3μg/mL。印楝素A和印楝素B在3μg/mL的剂量下处理后72 h,小菜蛾3龄幼虫的死亡率分别为90.42%和84.11%;在5μg/mL的剂量下处理后72 h,棉铃虫3龄幼虫的死亡率分别为99.1%和100.0%;在0.5μg/mL的剂量下处理后72 h,斜纹夜蛾4龄幼虫体重降低率分别为57.5%和72.73%;在0.8μg/mL的剂量下处理后72 h,棉铃虫3龄幼虫体重降低率分别为84.1%和80.9%。     

0.3%印楝素乳油防治牧草地土蝗田间药效试验

土蝗是一种杂食性害虫,历年在我省发生严重。为了综合治理蝗虫,减少农药对环境的污染,保护天敌,2005年进行0.3%印楝素乳油防治土蝗大田药效试验,现将试验结果分述如下:1试验药剂及来源1.1试验药剂0.3%印楝素乳油(成都绿金生物科技有限公司提供),通用名称toosedern。1.2对照药剂     

中国区域性环境因子与蝗虫防治

综合分析我国区域性环境因子中的气候、土质、植被、地形、水文等对蝗虫在我国的分布、生长发育的影响,并在此基础上,得到蝗虫对其生存环境具有很大的选择性,区域性环境因子对蝗虫生长发育的适宜性是蝗虫暴发成灾的主要原因,则可根据蝗虫生长发育及分布的规律性依据区域性环境因子对蝗灾的形成进行预防。进一步分析得知:蝗虫的治理应重在预防,生态防治是重中之重,蝗灾形成后的治理已对农牧业造成了危害,并且在目前蝗虫的治理方法中,化学防治只能进行蝗灾治理的应急措施,物理防治、不危害生态的生物防治、生态改造是首选的防治方法,这样才能做到蝗虫的"不形成、不扩散、不成灾",达到生态治理蝗虫的目的。     

国内外蝗虫研究发展动向初探

蝗虫是广泛分布于世界各地尤其是中低纬度地区的一种昆虫，其分布广泛性和危害严重性使之成为多门学科重要的研究对象之一。本文比较系统地总结了当前国内外蝗虫研究状况和近新进展，初步探讨了蝗虫研究中的若干新领域与新技术，对开展相关研究有一定的借鉴意义。     

Insecticide resistance in disease vectors of public health importance

Vector-borne diseases are a global problem--a trend that may only increase if global temperature rises and demographic trends continue--and their economic and social impact are enormous. Insecticides play a vital role in the fight against these diseases by controlling the vectors themselves in order to improve public health; however, resistance to commonly used insecticides is on the rise. This perspective outlines the major classes of disease vector control agents and the mechanisms of resistance that have evolved, arguing that effective resistance management strategies must carefully monitor resistance in field populations and use combinations of the limited modes of action available to best effect. Moreover, the development of novel insecticide classes for control of adult mosquitoes and other vectors becomes increasingly important.     

农药生态风险评价述评

风险一般指遭受损失、损伤或毁坏的可能性。生态风险是生态系统及其组分所承受的风险。生态风险评价是对产生不利的生态效应的可能性进行评价的过程。农药生态风险评价是采用生态风险评价技术评价农药给整个生态环境带来的风险。本文就农药生态风险评价的基本概念、过程和模型、内容和方法以及农药生态风险的评价研究现状进行了述评。     

6种杀虫剂对甜菜夜蛾的田间药效评价

通过6种不同杀虫剂对甜菜夜蛾的田间药效试验,结果表明:0.2%甲胺基阿维菌素苯甲酸盐微乳剂4000~6000倍稀释液对甜菜夜蛾有较好的防治效果,其防效在90.4%以上;2.02%甲胺基阿维·高氯乳油1000倍稀释液的第7d防效为91.9%;0.9%阿维菌素乳油1500倍稀释液在第3d的防效为89.5%,这些药剂均是当前防治甜菜夜蛾的优良药剂。     

农药混配室内毒力测定的一种实验技术

本文介绍了一种用于测定杀菌剂之间相互作用的实验设计，笔者借且作杀虫剂混配室内毒力测定，该实验设计具有覆盖面宽，成功率高，工作量小等特点。     

Insecticide resistance status of Aedes aegypti (L.) from Colombia

BACKGROUND: To evaluate the insecticide susceptibility status of Aedes aegypti (L.) in Colombia, and as part of the National Network of Insecticide Resistance Surveillance, 12 mosquito populations were assessed for resistance to pyrethroids, organophosphates and DDT. Bioassays were performed using WHO and CDC methodologies. The underlying resistance mechanisms were investigated through biochemical assays and RT‐PCR. RESULTS: All mosquito populations were susceptible to malathion, deltamethrin and cyfluthrin, and highly resistant to DDT and etofenprox. Resistance to lambda‐cyhalothrin, permethrin and fenitrothion ranged from moderate to high in some populations from Chocó and Putumayo states. In Antioquia state, the Santa Fe population was resistant to fenitrothion. Biochemical assays showed high levels of both cytochrome P450 monooxygenases (CYP) and non‐specific esterases (NSE) in some of the fenitrothion‐ and pyrethroid‐resistant populations. All populations showed high levels of glutathione‐S‐transferase (GST) activity. GSTe2 gene was found overexpressed in DDT‐resistant populations compared with Rockefeller susceptible strain. CONCLUSIONS: Differences in insecticide resistance status were observed between insecticides and localities. Although the biochemical assay results suggest that CYP and NSE could play an important role in the pyrethroid and fenitrothion resistance detected, other mechanisms remain to be investigated, including knockdown resistance. Resistance to DDT was high in all populations, and GST activity is probably the main enzymatic mechanism associated with this resistance. The results of this study provide baseline data on insecticide resistance in Colombian A. aegypti populations, and will allow comparison of changes in susceptibility status in this vector over time. Copyright © 2011 Society of Chemical Industry     

Insecticide resistance compromises the control of Aedes aegypti in Bangladesh

BACKGROUND

With no effective drugs or widely available vaccines, dengue control in Bangladesh is dependent on targeting the primary vector Aedes aegypti with insecticides and larval source management. Despite these interventions, the dengue burden is increasing in Bangladesh, and the country experienced its worst outbreak in 2019 with 101 354 hospitalized cases. This may be partially facilitated by the presence of intense insecticide resistance in vector populations. Here, we describe the intensity and mechanisms of resistance to insecticides commonly deployed against Ae. aegypti in Dhaka, Bangladesh.

RESULTS

Dhaka Ae. aegypti colonies exhibited high-intensity resistance to pyrethroids. Using CDC bottle assays, we recorded 2–24% mortality (recorded at 24 h) to permethrin and 48–94% mortality to deltamethrin, at 10× the diagnostic dose. Bioassays conducted using insecticide–synergist combinations suggested that metabolic mechanisms were contributing to pyrethroid resistance, specifically multi-function oxidases, esterases, and glutathione S-transferases. In addition, kdr alleles were detected, with a high frequency (78–98%) of homozygotes for the V1016G mutation. A large proportion (≤ 74%) of free-flying and resting mosquitoes from Dhaka colonies survived exposure to standard applications of pyrethroid aerosols in an experimental free-flight room. Although that exposure affected the immediate host-seeking behavior of Ae. aegypti, the effect was transient in surviving mosquitoes.

CONCLUSION

The intense resistance characterized in this study is likely compromising the operational effectiveness of pyrethroids against Ae. aegypti in Dhaka. Switching to alternative chemical classes may offer a medium-term solution, but ultimately a more sustainable and effective approach to controlling dengue vectors is required. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

有机磷杀虫剂的选择性与安全性

农药的安全性愈来愈受到人们的关注,有机磷杀虫剂作为主要的杀虫剂种类之一,其生产及使用在我国占有重要的地位。本文从有机磷杀虫剂的特点及作用靶标详细介绍了其选择性与安全性的关系。