Stability and Biological Activity of Cyfluthrin Isomers

A GC-MS method capable of completely separating the four pairs of diastereoisomers of cyfluthrin is presented and the method used to show that isomerisation of the cyfluthrin enantiomers occurs in methanol. This methanol-induced isomerisation could also be demonstrated by bioassays using water fleas. The biological activities of the various cyfluthrin isomers contained in the commercial products cyfluthrin and beta-cyfluthrin were assayed using several strains of lepidopteran larvae including Plutella xylostella, Heliothis virescens and Spodoptera frugiperda. With the susceptible strains, the efficiencies of the isomers mixtures of cyfluthrin and beta-cyfluthrin were shown to obey the rules of additivity. However, in tests with a resistant strain of P. xylostella originating from Thailand, the ‘inactive’ isomer III acted synergistically with the active isomer IV. Resistance factors in strains of H. virescens and P. xylostella were found to be higher with cis than with trans isomers. This probably contributes to the superior action of cyfluthrin and beta-cyfluthrin against various pests of agricultural importance since the commercial products contain a high content of trans isomers (‘high trans pyrethroids’).     

氟氯氰菊酯与高效氟氯氰菊酯危险性分类研究

采用联合国TDG体系、联合国GHS制度、欧盟CLP法规、中国与化学品分类相关的国标对氟氯氰菊酯与高效氟氯氰菊酯进行了危险性分类,得到了权威的分类结果,结论有助于两种农药的全生命周期正确操作与处理。     

3种鳞翅目化学药剂对烟田天敌昆虫种群的影响

研究以鳞翅目害虫烟青虫和斜纹夜蛾为防治对象,对比研究了甲维盐、氯虫苯甲酰胺和高效氟氯氰菊酯3种化学药剂对二者的防控效果,并在此基础上了解了3种化学药剂对烟田蜘蛛、草蛉、隐翅虫以及蚂蚁等天敌昆虫的影响。结果表明:3种药剂对烟青虫均有着较好的防治效果,施药3 d和7 d后防效均达90%以上,药剂之间没有差异;但是,施药后7 d,高效氯氟氰菊酯对斜纹夜蛾的防效会降低,其防治效果显著低于甲维盐和氯虫苯甲酰胺;同时,3种化学药剂对田间天敌昆虫均有抑制作用,施用甲维盐和氯虫苯甲酰胺后,天敌昆虫的增长率变缓;而施用高效氯氟氰菊酯后,天敌昆虫表现出负增长率。     

Comparative Toxicity of Selected Insecticides to Phytoplasma Transmitted Leafhopper Cicadulina bipunctata （Melichar）

Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin （pyrethroids）, imidacloprid （neonicotinoids） and abamectin （natural compounds）--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.     

高效氟氯氰菊酯定量分析方法研究

研究了正相高效液相色谱法定量分析高效氟氯氰菊酯的方法。本方法在20～200μg进样范围内呈线性,相关系数值(r)为0.9999。测得的回收率为98.8%￣100.73%,变异系数<2%。     

棉叶、棉籽及土壤中高效氟氯氰菊酯残留量的气相色谱分析

系统地研究高效氟氯氰菊酯在棉叶、棉籽及土壤中的残留量,促进安全生产。采用乙腈提取,固相萃取法净化棉叶,用有机滤膜净化土壤、棉叶和棉籽,通过气相色谱-ECD对棉籽、棉叶及土壤中的高效氟氯氰菊酯残留进行测定。该分析方法的添加回收率在93.4%~118.6%之间,相对标准偏差在1.8%~5.9%之间,最低检出浓度为0.02mg/kg。方法简便、快速、准确度高、精密度好。