Worms in Grapes

Grape Berry Moth

• The grape berry moth can be found in nearly all locations east of the Rocky Mountains in the United States, and feed on both wild and cultivated grapes. When the larva first hatches, it is white with a brown head. As it matures, it turns green and then purple, reaching 10 millimeters in size. The larvae create white webs that surrounds clusters of grapes and feed on the stems, leaves and berries, eventually burrowing inside the grapes.

Grapeleaf Skeletonizer

• Grapeleaf skeletonizers range throughout the majority of the United States wine-producing areas and can defoliate entire grape vines. The larvae are yellow with black spots or bands, and feed in large groups, usually side by side in a row. Grape leaves that have been infected by the insect will have a brown, "skeletonized" appearance. The Granulosis virus is a biological method that is commonly used to control this pest.

Grape Root Worms

• The grape root worm can be found from the eastern coast to the Midwest and Texas. The larvae have a creamy white appearance with dark brown heads. They hatch from eggs laid under the bark of the vine and eat the small roots of the plant, creating pits in the larger roots. The adults emerge in early to mid-summer and leave chain-like feeding marks on the grape plants.

Sawfly Larvae

• Sawfly larvae feed on the grape plant at night and can be difficult to spot during the day. They start feeding on the undersides of leaves, creating skeletonized leaf tissue, and eventually bore holes into the leaves. There are several species of sawflies that can affect grapes.