What's Eating My Grapes?
A grapevine feeds insects in June, birds in August, and everything else in between. Sort the leaf-eaters from the fruit thieves and the season gets manageable.
The usual suspects
Japanese beetles
The signs: Leaves skeletonized to brown lace across the top of the canopy in midsummer.
What it looks like: Metallic green-and-copper beetles massed on sun-lit foliage.
What to do: Morning knockdowns into soapy water; established vines tolerate startling amounts of leaf lace, so don't panic-spray.
Grape berry moth
The signs: Berries webbed together with silk, purpling early, with a small larva and frass inside; entry holes where berries touch.
What it looks like: A small caterpillar working inside clusters — the vineyard's signature pest east of the Rockies.
What to do: Remove and trash webbed berries and infested clusters as found; clean up leaf litter under vines where they overwinter.
Birds
The signs: Whole clusters stripped or pecked as sugar peaks, veraison to harvest.
What it looks like: Flocks time it better than a refractometer.
What to do: Net the fruit zone or bag prized clusters with organza bags at coloring.
Raccoons and opossums
The signs: Low clusters torn off, canes pulled down, fruit strewn — night work.
What it looks like: Whole-cluster removal beyond any bird's ambition.
What to do: Electric strand along the fruit wire before ripening; harvest low clusters first.
Grape phylloxera
The signs: Warty pea-sized galls on the undersides of leaves.
What it looks like: A tiny aphid relative inside the galls; American vines and hybrids mostly shrug it off.
What to do: On established American-rooted vines, leaf galls are cosmetic — remove heavily galled leaves and move on.
Wasps and hornets
The signs: Ripe berries hollowed to skins, wasps working the cluster.
What it looks like: They usually enlarge damage birds or moths started.
What to do: Harvest promptly at ripeness, remove damaged berries, and hang traps away from (not in) the vines.
When it's not a pest at all
Berries that shrivel into hard black mummies with tan leaf spots are black rot, the East's defining grape disease — sanitation and sprays, not traps. White powdery film is powdery mildew.
Or just point your phone at it
Snap a photo of the leaf, the bug, or the droppings, and Harold — the advisor built into Homestead Paradise — names what he sees, tells you friend or foe, and what he'd do next. Honest when he's unsure, and careful where it counts.
Put Harold's Eyes on it — free 14-day trial