Here's something that I havent seen before. What causes this? Mosaic virus? Its on a Pristine Apple tree on M111 that I planted this spring. A couple leafs have fallen off.
This is an insect issue, not a disease. It looks a lot like the damage generated by pear slugs (sawfly larvae), which on occasion will munch an apple, cherry, plum or other member of the rose family although pears are their fave.
Thanks, that's good to know, I'll be able to treat it