皖南单季稻区二化螟发生特点及其回升原因

Study on the Character of Rice Stem Borer Occurrence in Single-season Rice Region in Southern Anhui

90年代后期 ,二化螟发生出现了明显的新特点 :回升势头猛、发生型改变、发生期异常等。对皖南单季稻区历年二化螟发生情况进行分析认为 :7、8月份高温 ,主防农药品种防效下降 ,秋播免 (少 )耕面积扩大以及种植业结构调整 ,作物多元化是导致二化螟危害势头回升的主要原因。

New characters of rice stem borer occurrence including the rapid appearance again, the change of occurrence type and the abnormal of occurrence period were present in the 1990s. The data about rice stem borer occurrence in Southern Anhui showed that control efficiency of major agri-chemicals was decreased in high temperature from July to August. The extension of non-tillage seeding area, planting structure adjustment and the multi-crop planting were main reasons resulting in its rapid occurrence again in rice growth period.