| 释义 |
weeping elm
基本例句
垂榆
Byctiscus ulmi is one of the main insect pests in Weeping Elm of Xining region. The insect pest is happened a generation in a year in Xining region. 14.8 ovums were borthed by a female pest.榆叶象甲是西宁地区垂榆上的主要害虫之一;该虫在西宁地区每年发生一代;每头雌虫平均产卵量为14.;8粒;产卵部位集中于叶背;卵期8d左右;幼虫历期25d左右;老熟后在叶柄基部作茧化蛹;蛹期16d左右;从9月下旬起成虫在枯枝落叶层内进入越冬状态。 |