What's eating my chardonnay grape?

Chardonnay vines face grape berry moth that destroys fruit from inside, Japanese beetle that skeletonises foliage, and leafhoppers that stipple leaves and reduce photosynthesis. Powdery mildew often follows pest stress. Deer and birds also damage vines and fruit. Good canopy management and early-season scouting are essential.

Early larvae kill flower clusters; later generations bore into berries, causing shrivelling, secondary rot, and significant crop loss. Use degree-day models or pheromone traps to time sprays; apply Bacillus thuringiensis (Bt) or spinosad at egg-hatch; remove dropped berries from under vines.

Adults skeletonise leaves by eating tissue between veins, leaving a lacy brown appearance; clusters of beetles feed together. Hand-pick beetles into soapy water in the morning; use kaolin clay as a deterrent; avoid mass-pheromone traps which draw more beetles to the area.

Nymphs and adults stipple leaf surfaces white or pale yellow, reducing photosynthesis; cast skins on leaf undersides are a key diagnostic sign. Encourage natural enemies (parasitic wasps); remove weedy ground cover that hosts overwintering adults; insecticidal soap on leaf undersides if populations are high.

Peck ripening berries, accelerating rot and reducing harvest; damage is often worst on perimeter vines. Drape fine-mesh bird netting over the canopy just before veraison (colour change); tie securely at the base.