1. An insect that feeds on hemlocks; its egg sacs are small fuzzy white balls like artificial snow on a Christmas tree.
以铁杉为食的昆虫；其卵囊为有绒毛的小白球，形似圣诞树上的人造雪。
hemlocks什么意思
2. The presence of scales kept the adelgid`s numbers down, which led to less toxin and healthier hemlocks.
介壳虫在与球蚜同栖时挤掉了部分数量的后者，减少了铁杉的中毒量及树木受害的程度。