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棉铃虫在三门湾棉区属偶发性害虫,70年代初发生重,其后,虽有个别年份发生较重,但总的发生趋势属轻。1994年四代棉铃虫又严重发生危害,1996年从二代开始,部分棉田就有危害,三、四代卵量急剧上升,呈大发生趋势,对棉花生产构成严重的威胁。由于棉铃虫属偶发性害虫,要作系统研究难度较大,特别在测报资料统计标准上尚未完善,以致各地测报、植保部门在棉铃虫的发生期、发生程度等关键问题上只能就事论
The cotton bollworm is an accidental insect pest in the Sanmen Bay cotton area, which occurred in the early 1970s. Afterwards, although the occurrence of heavier individual years occurred, the general trend was light. In 1994, the fourth generation of cotton bollworm was seriously endangered. Since the second generation in 1996, some cotton fields have been harmed. The fecundities of the third and fourth generations have risen sharply and are in a tremendous trend, posing a serious threat to cotton production. Because the bollworm is a sporadic pest, it is very difficult to do systematic research, especially on the statistical standards of the data of the survey and forecast, so that the measurement report and the plant protection department can only discuss on the key issues such as the occurrence and degree of the cotton bollworm