mealybug \meal"y*bug`\, mealy bug \mealy bug\
(m[=e]l"[y^]*b[u^]g`), n. (Zool.),
Any of several homopteran scale insects (as, {Coccus
adonidum}, and related species of the families
{Pseudococcidae} and {Eriococcidae}), that cover themselves
with a white powderlike or cottony wax secretion. They are
common plant-eating pests in hothouses and are also
destructive of fruit trees.
[1913 Webster + WordNet 1.5]