上海郊区的棉铃虫一年发生四到五代,从第二代开始进入棉田为害,其中以第三、四代,特别是第四代,发生量大,为害棉花最为严重,是重点防治的世代。根据广大群众的经验,在产卵盛期喷药,以杀灭虫卵和初孵幼虫,防治效果较好。因此,我们于1972年以上海县北桥公社为基点,摸索了第四代产卵盛期的预测方法。 1.发生期预测的三环节根据发育进度推算害虫发生期的“发育进度法”,是当前广泛使用的害虫预测预报法。这类方法的优点是它考虑到多方面环境条件对害虫发育速度的综合影响,并以田间害虫 The cotton bollworm in the suburbs of Shanghai takes four to five generations a year and enters the cotton fields from the second generation. The third and fourth generations, especially the fourth generation, occur in large quantities and cause the most serious damage to cotton. According to the general public’s experience, spawning in the spawning period to kill eggs and newly hatched larvae, prevention and treatment is better. Therefore, in 1972, we started with the North Bridge commune in Shanghai and Shanghai and explored the prediction method of the fourth generation of spawning periods. 1. The three stages of the prediction of the occurrence According to the progress of the development of pests estimated the “progress of development” is the currently widely used pest prediction and forecasting method. The advantage of this type of approach is that it takes into account the combined effects of various environmental conditions on the rate of pest development and uses field pests