Q.Hi. We are wondering what this “disease” is on the leaves of one of our apple trees?
As the leaf gets more “covered” it starts to curl up – as in the final photo. They don’t appear to be moving, so we didn’t think they are aphids – but have no clue!!! Thank you for any help you can provide.
This appears to be a heavy Aphid infestation.
Neem Oil is a good treatment.
Follow packaging directions for application. I would recommend treating every 3 days for 2 weeks.