小麦叶蜂的生物学特性及防治研究

小麦叶蜂在信阳一年发生一代。成虫初见于２月上旬，盛见于２月下旬到３月下旬；卵初见于２月中旬，盛见于３月上旬到４月上旬；幼虫五龄，初见于３月下旬，盛见于４月到５月上旬。以幼虫越夏，和以幼虫和蛹越冬。幼虫入土越夏深度在２０ｃｍ以下的占９７．５％。幼虫喜适湿度较干燥的环境中生存为害，四到五龄为暴食期。防治的有利龄期为三龄。在ｍ￣２内有三龄幼虫２５头为防治指标。防治幼虫的有效农药有５０％辛硫磷、５０％甲胺磷、４０％水胺硫磷以及４．５％甲敌粉等。

Studies on the Biology and Chemical Control of Wheat Sawfly

The wheat sawfly Dorlerus tritici Chu completes one generation each year in Xinyang.The adults emerge as early as mid February,but most of the abults occur fron late February to late March. The abults begin to lay eggs in mid February.Most eggs are laid from early March to early April. The eggs begin to hatch in late March.The larvae stage ranyed from early April to early May. The larv has fifth instars,The larva oversummer 20cm deep in the soil and continue to overwinter in the same place.A few of them overwinter in pu-pa. The larva prefer to live and damage in the dry conditions.The consumption of 4 5 instar larva accunt for mare than 80%.of the total consumption.The economic threshoid of this pest can be set as 25 larva in the third instar per square n1eter. Many organophosphorous in-secticides such as methamidophos,phoxim ,Isocarbophos can be used to control the pest ef-fectively.