三化螟第四代是为害双季晚稻,造成双季晚稻减产的主要害虫之一。如汉川县1964年由于遭到第四代三化螟的为害,使双季晚稻白穗率最高的达到6.86%。因此,了解三化螟三代转四代的消长因素,以掌握第四代发生发展规律,及时、准确地指导大田防治工作,对夺取双季稻的稳产高产,有着十分重要的意义。 The fourth generation of Borer was one of the major pests that damaged the double-season late rice and resulted in the decrease of double-season late rice. For example, in 1964, Hanchuan County suffered from the damage of the fourth generation of rice stem borer, causing the highest rate of white spike in double-season late rice reaching 6.86%. Therefore, it is of great significance to understand the growth and decline of the third generation to the fourth generation of the stem borer, to understand the occurrence and development of the fourth generation, and to guide the prevention and control work in the field in a timely and accurate manner.