阿维菌素液体制剂理化性能研究及对小菜蛾室内毒力评价

Physical and Chemical Properties of Abamectin Liquid Formulations and Bioassay against Plutella xylostella L.

[目的]综合评价阿维菌素乳油、水乳剂和微乳剂3种液体剂型。[方法]通过理化性能、持液量和对小菜蛾的室内毒力等测试进行试验。理化性能表面张力、接触角分别采用铂金吊环法和视频法;持液量采用浸渍法;室内毒力采用浸虫法。[结果]在相同质量浓度时,微乳剂的表面张力最低,其临界胶束质量浓度约为12.5 mg/L,在甘蓝叶片上的接触角和扩展半径均优于乳油和水乳剂;水乳剂和乳油结果相当。质量浓度为10 mg/L时3种制剂在甘蓝叶片上的持液量的顺序为微乳剂>水乳剂>乳油。微乳剂对小菜蛾幼虫的活性最高,48 h对小菜蛾的LC50值为0.998 mg/L,相对于乳油呈明显增效,毒力比值为1.68,水乳剂和乳油活性差异不大,72 h试验结果与48 h的试验结果类似。[结论]微乳剂和水乳剂是能够取代乳油的行之有效的剂型,且微乳剂比水乳剂更有优势。

[Aims] It was to evaluate three liquid formulations of abamectin including emulsifiable coneentratefEC）, emulsion in water（EW） and microemulsion（ME）. [Methods] The physical and chemical properties consisting of dynamic surface tension and contact angle data, maintained quantity of the liquid in leaf and bioassay against Plutella xylostella L. in laboratory were obtained using a platinum drop shape analysis system, video method, immersion method and insect dipping method. [Results] The results showed that： At the same concentration, the surface tension of ME was the lowest, and the contact angle and expansion diameter on cabbage leaves were superior to that of EC and EW, while the results of EC and EW were almost the same. Critical micelle concentration（CMC） in ME was 12.5 mg/L while it was not observed significantly neither in EC nor in EW. Maintained quantity of the liquid by leaf of the three formulations was ME〉EW〉EC at the concentration of 10 mg/L. ME exhibited the highest activity against P. xylostella L. larvae and the LC^oin 48 hours was 0.998 mg/L which was higher than that of EC, and the synergistic ratio related to EC was 1.68, meanwhile there was no difference between EW and EC. The result in 72 hours was similar to that in 48 hours. [Conclusions] ME and EW are the effective pesticide formulations to replace EC, and the results of ME is better than that of EW.