How to identify and get rid of grapeleaf skeletonizer

If you are the proud owner of a grapevine growing in your backyard, then grapeleaf skeletonizers can be pretty annoying. However, for the rest of us, this metallic blue moth can be a fascinating find.

Grapeleaf skeletonizers are striking moths, but they are also beautiful caterpillars. Females lay their eggs on grapevines, Virginia creeper, raccoon grape, and other vines in the grape family. The eggs hatch into these black and yellow caterpillars that can defoliate a grapevine. They often line up side by side underneath the leaf, eating only the leaf tissue between the veins.

Grapeleaf skeletonizers are most easily identified by the damage they cause to grapevines. The larvae feed in groups, stripping away the green tissue of the leaves and leaving only the veins, creating a “skeletonized” appearance. The larvae themselves are bright yellow with black bands and covered in short hairs.

The adults are dark metallic blue with a reddish-orange collar around their heads.

How big are grapeleaf skeletonizers?

The larvae can grow up to about 3/4 of an inch long, while the adult moths have a wingspan of about 1 inch.

Grapeleaf skeletonizers are most commonly found in the western and southwestern United States, particularly in grape-growing regions. They are commonly found underneath leaves similar to plant bugs.

Grapeleaf skeletonizers are only a minor pest in grapes. However, if you find yourself with an abundance of these caterpillars on your grapevines, you may want to take action. You can manage a grapeleaf skeletonizer problem by:

• Handpicking: Regularly inspect your grapevines and remove any larvae you find by hand.
• Pruning: Remove and destroy any infested leaves or parts of the plant to reduce the larval population.
• Encouraging natural predators: Birds, predatory insects, and parasitic wasps can help control grapeleaf skeletonizer populations naturally.
• Using row covers: Protect your grapevines with row covers to prevent adult moths from laying eggs on the leaves.