癭蜂[tamabachi] gall wasp (any insect of family Cynipidae)
虫癭[chuuei] gall (abnormal plant growth formed by insects)

癭蝿[tamabae] gall midge (any insect of family Cecidomyiidae)

ランブル鞭毛虫[ranburubenmouchuu] giardia (flagellate protozoan)
ランブル鞭毛虫症[ranburubenmouchuushou] giardiasis
いも虫[imomushi] hornworm (caterpillar of a hawk moth)
益虫[ekichuu] useful insect
円虫類[enchuurui] round worms

夏虫[natsumushi] summer insect
蛔虫[kaichuu] roundworm (Ascaris lumbricoides)
害虫[gaichuu] harmful insect
鈎虫[kouchuu] hookworm
寄生虫[kiseichuu] parasite