6种药剂对羊蹄甲蚜虫防治的药效研究

Effect Test of Six Insecticides on Bauhinia purpurea

采用喷雾法测定了5种杀虫剂对棉蚜(Aphis gossypii)的室内毒力,比较了6种杀虫剂对苗圃中羊蹄甲(Bauhinia purpurea)袋苗上棉蚜的防治效果,同时分析了药剂对羊蹄甲生长指标的影响。结果显示:0.25%吡蚜酮对防治棉蚜效果最好,LC50仅为2.296 mg/L,25%噻虫嗪效果最差,LC50为41.396 mg/L。6种杀虫剂对苗圃袋苗上棉蚜的防治效果差异显著。施药处理7 d后,2.5%高效氯氟氰菊酯、0.25%吡蚜酮和1.2%烟碱·苦参碱的防治效果最好,防治效果分别为94.58%、94.09%和89.16%。同时施用过高效氯氟氰菊酯后的羊蹄甲袋苗在苗高、地径、地上部分鲜质量和地上部分干质量4个生长指标上均显著高于未处理的袋苗。因此2.5%高效氯氟氰菊酯和0.25%吡蚜酮对防治羊蹄甲苗期棉蚜有较好的速效性和持效性,同时1.2%烟碱·苦参碱也具有较高的防治效果,可以作为替代药剂穿插施用,以降低害虫抗药性风险。

The toxicity of five insecticides against Aphis gossypii was determined by quantitative and spray method.The results showed that pymetrozine0.25%WP had the highest toxicity to A.gossypii,with the LC50value of2.296mg/L and the toxicity of thiamethoxam25%WG to A.gossypii was not satisfied.Field control efficiency of six insecticides against A.gossypii was evaluated.The insecticides such as lambda-cyhalothrin2.5%SC,pymetrozine0.25%WP and nocotine·matrine1.2%EC had better control effects to A.gossypii.In which,control effects of three insecticides to the A.gossypii were94.58%,94.09%and89.16%respectively for seven days after treatment.At the same time,four growth indicators of Bauhinia purpurea after the application of lambda-cyhalothrin2.5%SC was significantly higher than the untreated seedling,such as seedling height,ground diameter,fresh weight on the ground and dry weight on the ground.The results showed that lambda-cyhalothrin2.5%SC and pymetrozine0.25%WP had a preferably good quick and persistent efficacy,and had been applied for pest control.The1.2%nicotine matrine EC could be used as a alternative insecticide to avoid aphid resistance.