Detoxification of Synthetic Pyrethroid Insecticides by Thermophilic Microorganisms

Microbially-mediated detoxification of five synthetic pyrethroid insecticides was achieved by a mixed culture growing anaerobically at 75°C. These pyrethroids were hydrolysed to non-insecticidal products after a period of 4–8 weeks' incubation. Of these five permethrin was the most readily transformed and Fastac the most recalcitrant. The mixed culture consisted of a facultative anaerobe and two other obligate anaerobes including a methanogen. This culture was derived from terrestrial sediments from hot-springs in New Zealand. This is the first reported microbial biotransformation of these xenobiotics at a temperature of 75°C. © 1997 SCI.     

Defensive role of tropical tree resins: antitermitic sesquiterpenes from Southeast Asian Dipterocarpaceae

Chemical components demonstrating antiinsectan properties were isolated and identified from crude resins of fourDipterocarpus species. The most active compounds against Southeast Asian termites (Neotermes spp.) proved to be alloaromadendrene, humulene, and caryophyllene. These results suggest that these sesquiterpenes, which occur in many dipterocarps, play an important role in defense against insects.     

白背飞虱对5种杀虫剂的敏感性测定

[目的]为指导白背飞虱田间药剂使用,采用稻茎浸渍法测定了湖南省长沙市白背飞虱种群对5种杀虫剂的敏感性.[结果]白背飞虱对噻虫嗪、吡虫啉、噻嗪酮、烯啶虫胺、异丙威的敏感度(LC50)分别为0.026 1、0.0534、0.0884、0.1759、27.366 1 mg/L.[结论]根据室内测定的敏感度以及药剂作用特性,在生产上可视白背飞虱发生情况,选择不同杀虫剂交替使用,以避免白背飞虱对杀虫剂敏感度的降低.     

荆州市郊小菜蛾抗性调查及分析

研究了荆州市郊小菜蛾对氯氰菊酯、敌敌畏、甲基对硫磷、毒死蜱、杀虫双、阿维菌素的敏感性水平。结果表明,小菜蛾对氯氰菊酯产生了较强的抗性(56.6倍),对甲基对硫磷和毒死蜱产生了中等程度的抗性(17倍和11.3倍),杀虫双、阿维菌素基本上未产生抗性。多功能氧化酶抑制剂的增效试验表明代谢水平升高不是小菜蛾对拟除虫菊酯类杀虫剂产生抗性的原因。     

2020年最新公开的含氟杀虫剂

综述了2020年ISO公开的含氟杀虫剂cyclobutrifluram、flupentiofenox、nicofluprole和cyproflanilide及其关键中间体的合成方法,且对其进行了简要介绍。     

食品中新烟碱类杀虫剂污染与控制研究进展

新烟碱类杀虫剂的问世给世界农业、畜牧业带来空前影响,在全球杀虫剂市场占有率达25％,然而新烟碱类杀虫剂可以对人类健康产生不利影响,其大量使用导致的食品污染引起了人们更多的关注与研究.目前国内外关于新烟碱类杀虫剂在食品中残留现状的研究调查报道较少,对于新烟碱类杀虫剂在食品中的危害和防治没有系统研究,本文查阅现有的研究文献...     

体外模拟消化过程中胡萝卜中新烟碱类杀虫剂的生物可及性研究

目的 基于体外胃肠道模型研究胡萝卜中啶虫脒、噻虫胺、吡虫啉、噻虫嗪4种新烟碱类杀虫剂(neonicotinoid insecticides,NNIs)的生物可及性,为其风险评估提供依据。方法 基于3种体外模型和胡萝卜在消化液中对NNIs的吸附过程,采用液相色谱-质谱法分析4种NNIs的含量,计算胡萝卜中NNIs的生物可及性和吸附量。结果 油脂的添加会增加胡萝卜中噻虫胺、噻虫嗪、吡虫啉的生物可及性,分别从(63.3±5.9)%、(60.7±4.5)%、(81.1±9.9)%增加到(79.3±6.1)%、(79.7±7.5)%、(94.3±2.7)%;而消化液中低浓度胆盐和胰酶的存在会降低NNIs的生物可及性。当胰酶质量浓度为0.25 g/L时,降幅可达4.1%(噻虫胺)～26.7%(噻虫嗪)。吸附实验结果表明,模拟肠液中4种NNIs的吸附亲和性系数KF值高于背景溶液。这表明胡萝卜在模拟肠液中有更高的吸附量,胆盐的加入增强了胡萝卜与NNIs的相互作用,降低了其生物可及性。结论 胡萝卜在不同体外消化模型中NNIs生物可及性存在差异,胃肠道中胆盐和胰酶含量的升高在一定程度上会降低NNIs的生物...     

Differential Responses of Wild and Laboratory Strains of the Housefly to PCBs

Mixtures of polychlorinated biphenyls, Aroclor 1242 and 1254, had different effects on larval survival of strains of the housefly Musca domestica recently derived from nature, a long-established laboratory strain, and a strain selected for insecticide resistance. All strains tolerated high levels of PCBs; however, both wild-derived strains exhibited unexpected increased survival upon exposure to moderate levels of PCBs alone, whereas the long-established laboratory strain exhibited lowered larval survival in the presence of PCBs. This was not related to a lack of uptake of PCBs by the wild-derived flies, since uptake was high and all major Aroclor GC fractions were represented in the emerging flies. There was increased effectiveness of insecticides in the presence of PCBs on the long-established laboratory strain, but there was no such synergism with insecticides for the wild-derived flies. Recent evolutionary modification of the effects of PCBs alone or in conjunction with insecticides has apparently occurred in this species.     

A rapid determination and extraction of three carbamate insecticides using LC-ESI-MS/MS: Application to their identification in a real river water sample

The aim of the present study was to attempt to describe a rapid procedure of purification and determination of the Zectran, Aminocarb and Bendiocarb in aqueous media using Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to electrospray ionisation mass spectrometry (ESI). Different solids phases ODS sorbents were evaluated for the extraction of analytes in water. Sensitivity was evaluated by determining the limit of detection and recoveries of these compounds. The optimum conditions of extraction were applied for the screening of these substances in river water sample (Oued Madjerda).