Vine

Man Eaters are rooted in place, so the job is covering ground rather than waiting for spawns. Find a run of caves at roughly the same depth in the underground jungle, join them with one long horizontal tunnel, and lay two rows of platforms down it. Sprinting that circuit puts you past far more of them per minute than wandering does. Hornets that show up can be knocked upward, since they cannot come back down through platforms.

They accumulate faster than you can spend them. Every recipe that calls for them wants only a few, while the same trips hand you stingers and jungle spores that go into far more. Once your recipes are covered, the leftovers are vendor trash and not worth a chest slot.