桑螟食叶量测定及其防治指标的研究

测定了桑螟幼虫一生的食桑量,以及食下量与发育历期的关系,为确定桑螟的防治适期及防治指标提供了科学依据。经过分析得出:桑螟的防治最佳时期应该为3龄以前;春夏季的防治指标为1200～1600头/亩,秋季的防治指标为1800～3200头/亩。

Measured the quantity of eaten leaves by Diaphania phloalis Walker and research on its occurring density be prevented and cured

Measured the quantity of leaves eaten by the whole life of Diaphania phloalis Walker, researched the relation between the quantity for eating and the time of growing. Those offered the scientific basis for determining the optimum period of prevention and cure. The results showed that the optimum period of prevention and cure should be before 3rd larval instars; the occurring density of prevention and cure in spring and summer is 1 200 - 1 600 heads/667m^2 , the occurring density of prevention and cure in autumn is 1 800 - 3 200 heads/667m^2.