螟害的轻重主要决定于螟卵的密度,明确卵量分布规律,是预测螟害发生程度和确定防治对象田的关键。三化螟卵量分布,决定于螟蛾盛发期,各稻作类型所处生育期及嫩绿程度,兹将分布规律总结如下。一、不同耕作制度地区的卵量分布三化螟各代卵块集中分布的稻作,一般是:第一代为分蘖期的早稻,第二代为分蘖期的单季晚稻,第三代为分蘖期的连作晚稻,第四代为孕穗期的连作晚稻。不同耕作类型区,由于适合一、二、三代产卵稻田面积比例的差异,则出现了卵量分布的不同集中程 The severity of stem borer is mainly determined by the density of the borer eggs and the clear distribution of the number of eggs. It is the key point to predict the occurrence of stem borers and to determine the control target field. Borer borer distribution, determined by the stem moth Sheng period, the types of rice growth period and the level of verdant will hereby summarize the distribution is as follows. First, the tillage system in different regions of the distribution of eggs in each generation of three generations of borer rice concentrated distribution of rice, are generally: the first generation of early rice at tillering stage, the second generation of tillering single-season late rice, the third generation of tillering stage Continuous cropping late rice, the fourth generation of booting successive cropping late rice. Different types of farming area, due to the first, second and third generation of spawning rice area ratio differences, there have been different distribution of egg concentration range