1999年黑龙江省五分之一的耕地面积上发生鼠害,因鼠害造成的粮食损失达10亿公斤以上。有关部门认为,1999年该省鼠害的程度已经超过鼠害大面积发生的80年代前期水平,农业部门的实地监测结果显示,许多地区老鼠密度已经高达8%到20%。据介绍,该省五常市1999年农田平均每亩有老鼠10至20只,仅在春天就毁苗一成左右,全市 Rodents occurred on one-fifth of the cultivated land in Heilongjiang Province in 1999, causing more than 1 billion kilograms of food losses caused by rodent pests. Authorities believe that the extent of rat damage in the province in 1999 exceeded that of the pre-80s that occurred on a large area by rodent pests. The field monitoring results of the agricultural sector show that the density of rats in many areas has been as high as 8% to 20%. According to reports, the province’s five permanent municipalities in 1999 the average farmland per acre has 10 to 20 mice, destroyed only about 10% of the spring in the city, the city