三化螟发生规律的研究

The Research of Tryporyga incertulas (Walker) Occurring Law

三化螟是海南岛水稻三大害虫之一。该虫每年发生6代,间歇年份大发生,造成稻谷严重损失。常年螟害率2—6％,大发生年局部地区高达50％以上。螟害率与发生量正相关;发生量与降水量负相关;发生期与气温负相关;上代与下代发生期正相关。根据冬季气温与降水量,可预测全年各代发生期与螟害率,掌握上述发生规律,做好测报与防治工作。

Trporyga incertulas (Walker) is one of three main insect pest to rice in Hainan Island. This kind of insect occurs six generations each year and occurs a great amount every alternate year. It brings about a serious damage to rice. In the general years, the rate of Tryporyga incertulas (Walker) damage is 2—6％; jn the great oeeuring year, the rate of regional area is more than fifty percent. There is a directcorretation between the rate and an occurring amount,and an inverse corrlation between the occurringamount ahd precipitation, an inverse correlation between the occurring stage and temperature; and the direct corrlation between the occurring stage of the upper generation ahd the lower one. According tothe temperature and precipitation in winter, we can premeasure the occurring stage and the rate of Tryporyga incertulas (Walker) of each generation in the whole year, and grasp preceding occurring law, and do eontrllling wok well.