不同药剂对麦蚜的防治作用及对麦田天敌昆虫的影响

Effects of Different Pesticides on Wheat Aphids and Natural Enemies

为了明确杀蚜药剂对麦蚜的防治效果、适宜的防治时期、对生态环境安全性和粮食作物食品安全性的影响,对4.5%氯氰菊酯、40%氧化乐果、40%毒死蜱、3%啶虫脒、10%吡虫啉等9种防治麦蚜的药剂进行了筛选,发现各药剂对麦蚜的防效较好,喷药后7 d防效均在90%以上。9种农药在喷施后的3 d内,对麦蚜的主要天敌蚜茧蜂和瓢虫影响较大,两种天敌数量锐减,但到7 d时各处理蚜茧蜂数量均有回升,其中不同剂型的吡虫啉、啶虫脒和鲁植顺克处理的蚜茧蜂数量同对照相差不大。由于瓢虫本身数量较少,而且喷药期内麦田瓢虫种群数量呈下降趋势,因此,种群数量回升不明显。在5月3日5、月8日5、月13日用4.5%高效氯氰菊酯、40%氧化乐果、5%蚜螨虫净超微乳油、20%吡虫啉可湿性液剂四种药剂进行了不同时期防治麦蚜农药试验,表明在麦蚜发生初盛期喷施杀蚜剂可以有效防治麦蚜。各农药处理小麦收获晒干后的农药残留量均在国家安全标准之内。根据试验结果,建议在麦蚜发生初盛期喷施吡虫啉或0.7%阿维.BT WP,可以减少喷药次数,提高作物产量,同时保护田间生态环境。

The 9 common used insecticides of cypermethrin 4. 5%EC, omethoate 40%EC, chlorpyrifos 40%EC, acetamiprid 3%EC, imidacloprid 10%EC provided excellent control for wheat aphids in fields. The control effects were over 90% at 7 days after spraying. The 9 insecticides had bad effects on aphidius and coccinellidae （lady beetles） in three days after spraying and the number of two natural enemies decreased rapidly. But on the 7th day, the number of the two natural enemies increased and there were difference between those treated with imidacloprid, acetarniprid and abamectin and CK. BT had no evident difference compared to the control. Because population of Coccinellidae was small and decreasing in this time, the increasing of coccinellidae was not evident. Wheat were treated once with cypermethrin 4. 5%EC, omethoate 40%EC, yamanchongjing 5%EC, imidacloprid 20% SC on May 3, 8, 13, respectively. The results indicated that it was appropriate to spray pestidde when the wheat aphids are initially prevailing. The pesticide residues in wheat were all below national criterion which is beneficial to produce good quality wheat. Summarizing all these results, it is suggested that spraying imidacloprid or abamectira BT can decrease the times of spraying pesticide and increase the yield of wheat and protect environment when the wheat aphids are initially prevailing.