论文部分内容阅读
雄县自七十年代以来,黄地老虎发展很快,主要为害芝麻。1976年以后,多数年份的落卵量在每平方米10粒以上,严重时达100粒以上。三龄以上幼虫常从地表把芝麻幼苗咬断,造成缺苗断垅。据观察分析:芝麻苗期每平方米有三龄以上幼虫一头,亩产减产6.33斤。 黄地老虎具有“发生严重,低龄难发现,高龄难除治,除治适期短”四个特点。必须做好预测预报,准确掌握虫情,抓住除治适期,打“突击战”,消灭在三龄入土以前。
Xiongxian since the seventies, yellow tiger developed rapidly, mainly for sesame damage. After 1976, the number of eggs lost in most years was over 10 grains per square meter and over 100 grains in severe cases. Third instar larvae sesame seedlings from the surface often snapped, resulting in lack of broken seedlings. According to observation and analysis: sesame seedlings per square meter has more than three larvae, yield reduction of 6.33 kg. Yellow tiger has a “serious, young age is difficult to find, elderly refractory rule, in addition to rule short duration” four characteristics. We must do a good job in predicting and forecasting, accurately grasping the pest, grasping the appropriate period of treatment and fighting the “assault war”, and eliminating it before the third age.