我市地处江淮平原，70年代以前，三化螟危害猖极，进入80年代，由于茬口布局的变化及有机氯等杀虫剂的应用，使三化螟的危害得到控制，但近年来，三代螟又呈回升趋势，危害逐年加重。笔者于1994年9月中旬对全市10个乡镇三代螟的发生情况进行了调查，平均白穗率0．61％（幅度0． The city is located in the Jianghuai Plain. Before the 1970s, the harm of the three stem borers was very rampant. In the 1980s, due to the changes in stubble layout and the application of pesticides such as organochlorines, the damage to the stem borer was controlled. However, in recent years, Third generation borer again showed a rising trend, the harm increased year by year. In mid-September 1994, the author investigated the incidence of three generations of rice borers in 10 towns and townships in the city, with an average of 0.61% of white spike (amplitude: 0).