The ovarian tubes of the adults feeding on aspen or apple trees are gradually shrielled,which can not produce mature ova, so the eggs stored in egg-calyces will not lay out.

• 以苹果树、杨树饲养的雌成虫，卵巢管逐渐萎缩，不能产生成熟卵，已贮存于输卵管萼内的卵也不能产出。