Parasitized bokdrolle?

Parasitized bokdrolle?

Observation - Parasitized bokdrolle? - Southern Africa. Description: Who makes holes in bokdrolle? A dung fly of some sort? A nesting bee? Too small for a dung beetle? All holes were on bottom side (dark area was on ground - underneath). Topmost drolle dont have holes.

Who makes holes in bokdrolle? A dung fly of some sort? A nesting bee? Too small for a dung beetle?

All holes were on bottom side (dark area was on ground - underneath). Topmost drolle dont have holes.