1962年以前,我县褐飞虱的发生数量很少,对生无明显影响,但1963年10月上旬,当晚稻灌浆乳熟段,突然猖獗,其发生面积之广、为害之重,为历史上少见。为害的一般规律是先在一块田的中心,然后速向周围扩展,3、5天内即可引起全田烂秆倒伏,成严童减产。 一、大田虫口密度的消长 褐飞虱在本县主要为害双季晚稻。当地农民传说:“7月以前虫较少,8月虫就多,9、10月里不得了”。据台州农业科学研究所1963年在插秧迟、早、中等连作晚稻田定点调查(五点取样)的结果:8月上旬稻苗移栽复活以后,田间开始出现褐飞虱;8月中下旬稻株进入旺盛分蘖期,由于食料充足,虫口密度直线上升;8月下旬末圆秆拔节,茎叶落黄,虫口密度下降;9月中旬进入孕穗和抽穗期,营养好转,再加上颱风、大雨过境,相对湿度增大,虫口密度又复回升;10月上旬,晚稻灌浆 Before 1962, the number of brown planthopper in our county was small and had no obvious impact on the students. However, in early October 1963, the rice ripening stage in the late rice suddenly became rampant and its area was wide and heavy, making it rare in history . The general rule of harm is first in the center of a field, and then quickly extended to the surrounding, 3,5 days can cause the entire field stalk lodging, into a strict cut. First, the decline of Daejeon pest population density Nilaparvata lugens in the county mainly damaging double-season late rice. Local peasants legend: “less pests in July, more than August insects, September, October incredible.” According to Taizhou Academy of Agricultural Sciences in 1963 in late rice, early, medium continuous cropping late rice paddy point survey (five sampling) results: early August seedlings transplanted resurrected, the field began to brown planthopper; late August rice plants into Strong tillering stage, due to adequate food, insect population density rose straight; late late August stalk jointing, stems and leaves fall yellow, population density decreased; booting and heading date in mid-September, nutrition improved, coupled with typhoon, heavy rain transit , Relative humidity increased, insect population density rose again; early October, late rice filling