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于2009年常规中稻的蜡熟前期、中期和黄熟期、枯熟期,分别取样观察大螟Sesamia inferens Walker的钻蛀危害习性。结果发现:单株螟害的蛀孔数一般为2～3个,多的达5个,而且表现白穗株>枯穗株>虫伤株。螟害株的蛀孔部位随着稻穗趋向成熟和大螟虫龄的增大,逐渐由稻株的中上部节间向中下部节间转移。其中,白穗株与枯穗株有70%以上的蛀孔分别分布于稻株由上向下的第1～3与3～5节间上;在水稻的这4个生长时期中,虫伤株有90%左右的蛀孔分别分布于稻株由上向下的第1～3、1～4和2～5、3～5节间上,全株虫量有85%以上依次分布于第1～3、2～4和3～5、3～5节间上,单株虫量4个时期最高分别为18、6、3、2头,同一节间内的4个时期最高虫量分别为12、5、1、1头;单个节间有多头螟虫时,80%以上为1～3龄幼虫。随着稻穗趋向成熟,白穗株和枯穗株上的虫量均逐渐下降,而虫伤株上的虫量则相对稳定或有上升的趋势;至枯熟期后,虫伤株的有虫株率和有虫孔率均稳定在30%以上。
In 2009, the routine mid-ripening of mid-season rice was pre-ripened, middle-aged and yellow-ripened, and the dry-ripening stage. Sampling habits of Sesamia inferens Walker were observed. The results showed that the number of moth per plant per plant was 2 ~ 3, more than 5, and white spike> white spike> insects. The borer sites of stem borers were gradually transferred from middle to upper internode to middle and lower internodes of rice plants with the maturity of rice and the age of stem borer increased. Among them, more than 70% of boreholes between white and spike strains were distributed in the upper and lower rice plants from 1 to 3 and 3 to 5, respectively. During the four growth stages of rice, About 90% of the moth boreholes were distributed in the rice plants from top to bottom 1 ~ 3, 1 ~ 4 and 2 ~ 5, 3 ~ 5 internodes, the whole plant more than 85% of insect population were distributed in the 1 to 3, 2 to 4, and 3 to 5, and 3 to 5 internodes. The maximum number of pests per plant in the four periods was 18, 6, 3, and 2, respectively. 12,5,1,1 head; when a single internode stem borers, more than 80% of 1 to 3 instar larvae. With the maturity of rice panicles, the number of white spike and dry spike strains decreased gradually, while that of insects was relatively stable or increased. After the dry season, Insect strain rate and wormhole rate were stable at 30%.