green caterpillar of a geometrid moth; pest of various fruit and shade trees
cankerworm详细解释
can.ker.worm n.（名词）The larva of either of two moths(Paleacrita vernata or Alsophila pometaria), destructive to fruit and shade trees. 尺蠖：两种蛾（春尺蠖 春虫属 或 秋尺蠖 林尺蠖属） 的幼虫之一，对果实和遮阳树有破害作用
