クロゲンの幼虫がハリガネムシ食べてたよ

Reiya WATANABE (2019) Field observation of predation on a horsehair worm (Gordioida: Chordodidae) by a diving beetle larva Cybister brevis Aubé
(Coleoptera: Dytiscidae). Entomological Science, early view.

いかにも美味しくなさそう。