对于粘虫的化学药剂防治,过去一般是在三龄期开始施药,并且取得了良好的效果。这是因为粘虫幼虫在三龄后才开始蚕食叶缘,食量逐渐加大,此时防治药剂便于接触虫体,可以达到消灭的目的。另外一些资料也曾记载,药剂防治粘虫的有利时机是在有大批三龄幼虫出现时期。近几年来,我们在实际工作中看到,当粘虫大 For armyworm chemical control, in the past usually started spraying in the third instar, and achieved good results. This is because the armyworm larvae began to erode the leaf margin only after the third instar, and the food intake gradually increased. At this time, the control agent was convenient for contacting the insect body and could achieve the purpose of extinction. Other information has also been recorded that the favorable opportunity for the prevention and control of armyworms with pesticides is when a large number of third instar larvae appear. In recent years, we have seen in practical work that when the armyworm is large