plant louse, louse - any of several small insects especially aphids that feed by sucking the juices from plants

Adelgidae, family Adelgidae - plant lice

Adelges piceae, balsam woolly aphid - a variety of adelgid

Adelges abietis, spruce gall aphid - a variety of adelgid

pine leaf aphid, Pineus pinifoliae - a variety of adelgid

woolly adelgid - an insect that feeds on hemlocks; its egg sacs are small fuzzy white balls like artificial snow on a Christmas tree