1.初步观察稻苞虫在武汉地区一年发生6代,第1代于4月中旬前后出现,为害野菱白及游草;第2代于5月间转入早稻为害,但数量少,为害轻;第3代于6月间为害中稻,数量较多,为害较重;第4代为害一季晚稻,数量最多,为害最重;第5代为害二季晚稻,数量显著减少,为害较轻;因之在防治上应以一季晚稻为主要防治对象。 2.生活史不整齐,各代重叠,但根据各种虫态和幼虫各龄虫的集中情况,可作短期的虫情测报,特别是7月中旬充分掌握虫情,及时防治是保证产量不使成灾的关键。 3.稻苞虫的天敌是种类多,形体小与其发生数量呈现了密切关系。当年稻苞虫能否是大发生,是在当年具体环境条件下所引起的死亡率与生存率的高低所决定。 4.凡1～3月份平均温度高,相对湿度大,当年有大发生的可能性,反之可能性小;6～7月份的雨水分布和大发生有密切联系,在一般雨量年份,6月下旬至7月上旬降水频度和强度均大,7月下旬即有大发生的可能性,仅7月中旬降水频度和强度均大的情况下,有中等发生的可能,在特殊雨量年份,6月下旬或7月上旬,降水频度和强度特大,可以引起大发生。 5.在早中稻时期,特别是中稻时期,结合中耕薅草,彻底摘毁虫苞,可以压低第4代虫数的来源,消灭为害,在一季晚稻时期,根据虫情及时(大约在7月20日前后)施用666粉剂防治,可以消灭为害,同 1. Preliminary observations The rice shellworm occurred in Wuhan area for 6 generations a year, the first generation appeared in mid-April around, causing damage to the wild rhododendron and grass; the second generation in May into the early rice damage, but a small number, The third generation harmed the middle rice in June with a large number and heavier damage. The fourth generation harmed the late rice in the late season with the largest number and the worst damage. The fifth generation harms the second season late rice, which is significantly reduced and less harmful. Therefore, in the prevention and treatment should be a quarter of late rice as the main control object. 2. Life history is not regular, the generations overlap, but according to the concentration of various insects and larvae of each age insects, can be used for short-term insect detection, especially in mid-July full grasp of insects, timely prevention and control is to ensure that the yield is not The key to disaster. 3. The natural enemies of rice insects are many species, small size and its occurrence showed a close relationship. Whether rice beetle can occur in that year is determined by the level of mortality and survival rate caused by the specific environmental conditions of the year. 4. Where 1 to March the average temperature is high, relative humidity, the possibility of a large occurrence that year, on the contrary the possibility of small; 6 July rainfall distribution and the occurrence of a close, in the general rainfall years, late June Precipitation frequency and intensity are both large in early July and large in late July. In the middle of July, precipitation and intensity are both moderate, and in the special rainfall years, 6 Late in the month or early July, precipitation frequency and intensity of large, can cause a big occurrence. 5. In the early mid-rice period, especially in the mid-rice period, combined with tillage grass, the complete eradication of insect bract can reduce the fourth generation of the source of the number of insects, eliminate the damage in the season of late rice, according to the situation in time (about July 20 days before and after) 666 powder control, you can eliminate harm, with