Honestly, I have not worked over there a whole lot. That spearmint is my cousin's baby.
I'll check into that about the leafhopper, it sounds likely to me too. My other cousin was primarily concerned as to whether there was any danger to using the leaves for tea or in food.
She also said the spots didn't appear right away but showed up suddenly shortly after she potted this up. She has potted another mint from somewhere else right next to these and it does not have the white spots. I don't know if it is in the same container or separate.
*goes to google up sage leafhopper*
(I will try to get a shot of the leaves underside later on.)
