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棉铃虫在我县逐渐由次要害虫转化为主要害虫。1968年以前,该虫仅在少数田块零星发生。1969—1970年,则在局部晚发旺长棉田发生,数量较多,八月中、下旬百株卵
The cotton bollworm gradually transformed from secondary pests to major pests in our county. Before 1968, the insects sporadically occurred in only a few fields. From 1969 to 1970, it occurred in some areas where there was a late onset of long cotton fields. There were a large number of eggs in mid-August and late January