What are Leaf Rollers
Leaf rollers are small greenish to green/brown caterpillars (moth larvae) that feed on leaves, buds and fruit, they're the worm in your apple (Or 1/2 worm as the case may be). They are a common problem on fruit trees and ornamental trees , occasionally on vegetable garden plants, but rarely. Some of the more prevalent and bothersome varieties include red banded leaf roller, fruit tree leaf roller, oblique banded leaf roller, variegated leaf roller, omnivorous leaf roller. Leaf rollers larvae feed on both fruit and foliage. Foliar injury is generally not a major concern.
Larvae may seal leaf surfaces together and live between them or fold leaves together and live in the folds. Larvae also feed within berries and fruit as the worm in your apple, and may not be noticed until harvest time, or at consumption. Young larvae feed on unfolded leaves. Older larvae fold the leaves in half and hold them in place with webbing. Damage results from the larvae feeding within the folded, rolled or webbed leaves, causing them to turn brown and die.
Monitoring should begin early. Look for folded or rolled leaves among the plants. The leaves may be discolored or show some feeding damage such as small holes in the leaves. Pick the rolled leaves carefully and examine for leaf roller larvae. If the rolled leaves do not have any larvae present, it is too late to control the larvae.