鄂尔多斯半日花提取物对美国白蛾卵和幼虫的毒杀作用

为了寻找新型的可防治美国白蛾的植物源杀虫剂,采用浸卵法研究鄂尔多斯半日花5种溶剂提取物对美国白蛾卵的毒杀作用效果,采用微量点滴法研究其对美国白蛾幼虫的触杀活性,采用夹毒叶碟法研究其对幼虫的胃毒活性.结果表明,这5种溶剂提取物具有强烈的杀卵作用,有一定的触杀作用,胃毒作用效果不明显.在杀卵试验中,甲醇提取物的杀卵效果最佳,质量浓度为200.00g/L时,杀卵率高达92.00%.在触杀实验中,水提取物的触杀效果最佳,浓度为200.00g.L-1时,48h的校正死亡率为58.33%.在胃毒实验中,水提取物的胃毒效果最佳,但质量浓度为200.00g/L时,48h校正死亡率也仅为23.33%.

Poison activities of Helianthemum ordosicum extractions on eggs and larvae of Hyphantria cunea

To find a new botanical insecticide to prevent Hyphantria cunea（Drury）,different concentrations of 5 kinds of crude extractions from Helianthemumordosicum were used to test the bioassay of action on eggs and larvae of Hyphantria cunea.The method of immersing eggs was employed to test the poison activities of the extractions on the eggs,micro spot method was used to test the contact toxic activity on the larvae,and poison sandwiched leaf dipped method was used to test the stomach toxic activity on the larvae.The results showed that most of concentrations of 5kinds of crude extractions from Helianthemum ordosicum had dominant poison effect on the eggs,certain contact toxic activity on the larvae,and unconspicuous stomach toxic activity.When the concentration of methanol extraction was 200.00g/L,the rate of killing eggs was highest,reached 92.00%.When the concentration of water extraction was 200.00g/L,the corrected death rate of contact toxic activity against 3rd larvae was highest,reached 58.33%in 48hours.When the concentration of water extraction was 200.00g/L,the corrected death rate of stomach toxic activity on the 3rd larvae was lowest,just reached 23.33%in 48hours.