20种植物甲醇提取物对萝卜蚜的触杀活性研究

目的]筛选对萝卜蚜(Lipaphis erysimi Kaltenbach)触杀活性较强的杀虫植物。方法]采用甲醇冷浸提取法对采自广西桂东部贺州姑婆山的15科20种植物进行了提取,并采用毛细管微量点滴法测定了20种植物甲醇提取物对无翅萝卜蚜的触杀活性。结果]在10μg/头浓度下,大叶白纸扇、变叶榕甲醇提取物对萝卜蚜的触杀活性最强,24 h校正死亡率分别为92.22%和92.15%;其次是山黄麻、光叶堇菜甲醇提取物,24 h校正死亡率分别为87.59%和82.95%;再次是剑叶耳草甲醇提取物,24 h校正死亡率为65.52%;其余15种植物甲醇提取物对萝卜蚜的触杀活性较低,24 h校正死亡率均在50%以下。其中大叶白纸扇、变叶榕、山黄麻甲醇提取物对萝卜蚜有较高的触杀毒力,其LD50分别为0.768 6、0.784 1和1.504 4μg/头。结论]大叶白纸扇、变叶榕、山黄麻3种植物极具开发潜力,值得进一步研究。

Contact Activities of 20 Plant Extracts against Lipaphis erysimi Kaltenbach

Objective] The aim was to screen out plants which had strong contact activity against Lipaphis erysimi Kaltenbach.Method]Twenty plant species which were collected from Gupo Mountain in Hezhou were extracted with methanol by cold soaking method.Contact activities of 20 methanol plant extracts to Lipaphis erysimi Kaltenbach were determined by topical application.Result] The methanol extracts from Mussaenda esquirolli Levl and Folium trematis Orientalis had the highest contact activities against Lipaphis erysimi Kaltenbach at the dose of 10 μg/larva,and their 24 h corrected mortalities were 92.22% and 92.15%,respectively.Next came Folium trematis and Viola hossei,and their 24 h corrected mortalities were 87.59% and 82.95%,respectively.The methanol extract of Hedyotis lancea had medium activity,with the 24 h corrected mortality of 65.52%.Methanol extracts of the other plants had low contact activities against Lipaphis erysimi Kaltenbach,with the corrected mortality being below 50%.The methanol extracts of Mussaenda esquirolli,Ficus variolosa and Folium trematis had high contact toxicity,with LD50 of 0.768 6,0.784 1 and 1.504 4 μg/larva,respectively.Conclusion] Mussaenda esquirolli,Ficus variolosa and Folium trematis show exploitation potential,and they are worth further studying.