any of various homopterous insects of the family Adelgidae, as Adelges abietis (spruce gall aphid) and Pineus pinifoliae (pine leaf aphid), that feed and form galls on conifers
Word origin
[‹ NL Adelgidae, equiv. to Adelg(es) a genus name (appar. ‹ Gk ádel(os) unseen, invisible (a-a-6 + dêlos visible, clear) + NL -ges ‹ ?: unexplained by the name's originator) + -idae-id2]