The type of leaves they eat depends on the specific moth species they will eventually become. For example:
* Some inchworms feed on oak leaves.
* Others prefer maple leaves.
* Some may specialize in fruit trees.
So, while they do eat leaves, you'll need to know the specific type of inchworm to determine what type of leaves it eats.
If you are curious about a particular inchworm, try searching for it online with a description or picture, and you may be able to find its dietary preferences.