Synonyms for Gallfly (same or very similar meaning)
WordNet sense 1 (small solitary wasp that produces galls on oaks and other plants):
gall wasp, cynipid gall wasp, cynipid waspWordNet sense 2 (fragile mosquito-like flies that produce galls on plants):
gall midge, gall gnatFrom the ODE community, based on WordNetadd/edit