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1987年我县麦粘虫特大发生,除少部分小麦田虫量略低外,50万亩大麦田虫口密度都在万头以上,个别田块高达7万多头。据统计,全县因粘虫咬断麦穗造成损失的面积约25万亩,其中掉穗率5～10％的面积近3万亩,少数田块掉穗率达30％以上,全县损失麦子441万公斤,为我县历史上所罕见。 初步分析,造成1987年粘虫大发生的因素有下列几点:(1)2月上旬的剧变低温,致使大量大麦麦
Mieyongchong in our county occurred in 1987, in addition to a small number of wheat field slightly lower than the amount of insects, 500000 acres of barley field pest population density in more than 10,000 individuals, individual fields up to 70,000 heads. According to statistics, the area of about 250000 hectares of the area damaged by armyworm biting off wheat ears, of which the area of 5% to 10% of the lost spikes is nearly 30000 mu, and the loss rate of the few fields is over 30% 4410000 kilograms of wheat, rare for my county history. Preliminary analysis of the factors that caused the emergence of the armyworm in 1987 include the following: (1) the rapid change of temperature in early February caused a large amount of barley