论文部分内容阅读
一九七○年以前,稻纵卷叶螟在我市只是在局部地区晚稻田间歇发生,而近几年在早稻和山区的单晚、中稻田为害也较严重。一九七三年以来,我所通过观察研究,初步弄清其发生为害基本情况和主要世代虫源地蛾迁飞规律。一、我区稻纵卷叶螟为害特点稻纵卷叶螟在我市一年发生7代。早稻发生3代,晚稻发生4代.其中第七代越冬;一代、四代在苗期至分蘖期为害;二代、五代在孕穗至抽穗阶段为害;三代、六代在灌浆乳熟阶段为害;三代、四代主要是为害山区单晚和中稻。双季稻区以二代、五代为害最重,受害面积最大;三代四代对山区单晚、中稻为害亦重;第四代多在晚秧田产卵孵化,由于秧田治虫频繁,故为害较
Before 1970, the leaf roller was only intermittently occurred in the late rice paddy in some areas in our country. In recent years, the single-cropping in the early rice and the mountainous areas and the damage in the middle paddy fields were more serious. Since 1973, through observation and study, I have made a preliminary study of the basic situation of its occurrence and the migration rule of moths in major generative generations. First, my area rice leaf roller damage characteristics Rice leafroller occurred in our city seven generations a year. The third and sixth generations occurred in the fourth generation of late rice and the second generation and fourth generation occurred in the second generation and fourth generation respectively, Three generations, four generations of major damage to the mountainous area and medium-sized rice. The second generation of rice in the second generation, the fifth generation of the hardest hit, the largest victims of the area; three generations and four generations of mountain night, midship damage; fourth generation and more late hatchling spawning hatching,