I have a large (20+ ft tall) sweet bay laurel tree in my backyard. I recently noticed a majority of the leaves have extremely tiny, shiny brown/black bumps on them.
From my research it seems like it may be scale, but I haven't seen any examples online of scale being so tiny. There is also no sticky residue/honeydew present, the bumps only appear on the tops of the leaves (not on undersides or stems), and they are virtually impossible to remove! I've tried scrubbing with a toothbrush, rubbing with a qtip dipped in rubbing alcohol, even soaking a leaf overnight to kill/soften the bumps and then scrub - nothing works. The only thing that does work is scraping them off, but even then they are stuck so hard I often rip the leaf in the process.
If anyone has any idea what these are I would be grateful. If they are scale, then how on earth would I treat them without being able to remove them? I'd like to avoid using anything harsh or systemic as I do use the (non-bumpy) leaves for cooking.
The tree is in zone 8 (Vancouver, BC) and is about 20-25 years old. Thanks!