甜菜筒喙象分布型与防治指标

本文首次报道了甜菜筒喙象卵和幼虫的田间分布型与防治指标。通过田间顺行逐株查卵,经概率分布分析看出,在百株有卵(虫)6～21粒(头)时为聚集分布。人工接卵模拟筒喙象为害采种甜菜产量损失结果表明,产量损失率与虫口密度呈幂函数相关(r=0.9913)。根据预测模型,在亩产种子100kg、单价2.2元/kg、防治费用2.85元/亩时,初拟防治指标为亩有卵420～640粒或亩有成虫20～28头为宜。

Distribution Form and Controlling Target of Lixus subtilis Boheman

This is 1st report on the distribution, form and controlling target of Lixus subtilis eggs and larva in the fields and find out the eggs plant by plant along rows in field, and analysis by the probability of distribution to give following resultss the crowding distribution with 6 ~21 bulbs of egg(or pest). The results of yield losses have shown that as power function correlation between ratio of yield losses and population density (r =0.9913**) while artificial inoculation of Lixus subtilis and simulating to damage the sugarbeet for seed collecting, according to the predicting model with seed yield were 100kg/mu, the unit cost at 2.2 Yuan/kg, the control fee was 2.85 Yuan/mu, preliminary draft the controlling targets were 420~640 eggs/mu or adult 20~ 28 bulbs/mu.