What is eating the leaves on my apple trees?

Question:

Something is eating the apple trees. They have bloomed, but the leaves are being attacked. Can you help determine what is eating them/how to get them to stop?

Answer:

Jonathan Foster, Home Horticulture Outreach Professional

There are numerous pests that can chew on apple leaves, and without other identifying clues it’s tough to say. Your photos definitely look more insect-related than mammal, so I’m wondering if you’ve noticed caterpillars of any kind on the tree. I will send a long a few links with things you can scout for among the foliage, and if you spot anything we can identify it and recommend an intervention. Be sure to check at various points through the day, from sunrise to after dark, as different pests may be active at different times.

Univ of MN Extension page on apple leaf problems

UMaine Cooperative Extension “Home Apple Orchard Pest Management Overview”

North Dakota State Univ Extension “Diagnosing Apple Tree Leaves with Holes or Webbing”

And because our new reality in Maine is living with the brown tail moth and its problematic caterpillars, I will mention it as a possible culprit, as apple is a favorite food.

Good luck, and happy gardening.