中华甲虫蒲螨防治双条杉天牛的试验分析

文章在试验的基础上，研究探讨了利用生物天敌中华甲虫蒲螨Pyemotes zhonghuajia Yu and Zhang防治双条杉天牛Semanotus bifasciatus（Motschulsky）的技术。本试验将有虫侧柏木段（长1m, 直径10cm）绑置在柏树林中以模拟田间状况，并在4月上中旬到5月下旬，每隔10天左右释放一次天敌蒲螨。每次设置两个蒲螨释放量及一个空白量。试验结果表明两个试验量即1管螨/木段和2管螨/木段对天牛幼虫的致死率差异不显著；并就天敌蒲螨释放时间对天牛致死率的影响分析得出，北京地区利用天敌蒲螨防治双条杉天牛幼虫的最佳时间为5月上中旬，即日均气温到达20℃以上。因此在实际的防治工作中，应在温度条件适合蒲螨寻找寄主时，利用较少的天敌投放量，尽早开展防治工作。

Study of utilizing Pyemotes zhonghuajia to control Semanotus bifasciatus beetles

Based on mass of trials, the paper discussed how to keep out Semanotus bifaseiatus （Motschulsky） by making use of Pyemotes zhonghuajia Yu and Zhang. In outdoor trials, we fixed up Platycladus orientalis blocks （1m in length and 10cm in diameter） on the truck of Sabina in a wood instead of trying on live trees. Before releasing Pyemotidae mites, we put Semanotus bifasciatus （Motschulsky） nymphas on Platycladus orientalis blocks as preparation, 30 ones for each block. The trials dates are from the middle of April to the end of May; we set two Pyemotidae mites releasing amounts and one blank as contrasting. The results showed that in Beijing the best time keep Out the pest by making use of Pyemotidae mites is the early and middle days in May, when the average temperature of the day is over 20℃ .As a result ,the reasonable method is utilizing smaller releasing amounts to control beetles as early as possible when the temperature is available.