6种药剂对羊蹄甲蚜虫防治的药效研究

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。

Effect Test of Six Insecticides on Bauhinia purpurea

The toxicity of five insecticides against Aphis gossypii was determined by quantitative and spraymethod. The results showed that pymetrozine 0.25% WP had the highest toxicity to A. gossypii, with the LC50value of 2.296 mg/L and the toxicity of thiamethoxam 25% WG to A. gossypii was not satisfied. Field controlefficiency of six insecticides against A. gossypii was evaluated. The insecticides such as lambda-cyhalothrin2.5% SC, pymetrozine 0.25% WP and nocotine · matrine 1.2% EC had better control effects to A. gossypii. Inwhich, control effects of three insecticides to the A. gossypii were 94.58%, 94.09% and 89.16% respectively forseven days after treatment. At the same time, four growth indicators of Bauhinia purpurea after the application oflambda-cyhalothrin 2.5% SC was significantly higher than the untreated seedling, such as seedling height, grounddiameter, fresh weight on the ground and dry weight on the ground. The results showed that lambda-cyhalothrin2.5% SC and pymetrozine 0.25% WP had a preferably good quick and persistent efficacy, and had been appliedfor pest control. The 1.2% nicotine matrine EC could be used as a alternative insecticide to avoid aphid resistance.