Characteristic Classification Description Image
Mine age Fresh mine is white and a black trail of frass is visible
Medium mine is mostly white, but with some browning and frass is less distinct
Old mine is mostly brown and frass is mostly indistinct
Presence of larva­­­ Larva removed a healthy larva was present and excised from the mine
Dead larva the remains of a dead larva were present within the mine
Empty no remains of a larva were present within the mine