Full depth mines
Full depth mines are easily recognisable because, when held against the light, they are transparant, without a green tinge – at the place of te mine all parenchyma has been eaten away.
“Full depth” is not beautiful English, but it is the best phrase available. The Dutch “voldiep” is certainly no better. The German equivalent is “beiderseitig”.
Mompha terminella on Enchanter’s Nightshade: full depth mine
Lyonetia clerkella on Cherry: full depth mine
Most sawfly larvae eat both layers of the parenchyma, but leave some remnants alone. This happens mostly in young larvae, like in Fenusa pumila, but a species like Metallus pumilus does so throughout its larval life. These mines, as long as they are fresh, partially or entirely have a greenish hue.
Fenusa pumila on Birch: more or less full depth mine