(A) Pteroptyx cf. valida (Olivier, 1883) larva, which was probably at its fifth instar, attacking Plectostoma laidlawi (Sykes, 1902) by shell-apertural entry. (B) Pteroptyx tener (Olivier, 1907) larva, which was probably at its fifth instar, attacking Plectostoma fraternum (Smith, 1905) by shell-apertural entry. (C) Atopos slug attacking Plectostoma concinnum (Fulton, 1901) by shell-drilling. (D) Atopos slug proboscis (marked with red outline) that was used for shell-drilling (the proboscis was not fully extended). (E) A drill hole on the shell of Plectostoma concinnum (Fulton, 1901) made by Atopos. (F) The appearance of the margin around the drill hole.