What's eating my grape 'frontenac'?

Grape 'Frontenac' is a vigorous cold-hardy red wine grape with good disease resistance. Key pests are grape berry moth larvae boring into clusters, Japanese beetle adults skeletonising leaves, and spotted wing drosophila in ripe fruit. Deer and rabbits target young canes in harsh winters. Grape berry moth is the most consistent annual pest.

Webbed, frass-covered clusters; larval boring into berries triggers Botrytis and bunch rots. Degree-day spray timing with Bt or spinosad at each egg-hatch generation. Remove old bark; sanitation reduces overwintering pupae. Mating disruption in blocks >2 acres.

Interveinal skeletonisation from June–August; vines can lose 30–40% leaf area in heavy years. Hand-pick or use pyrethroid sprays at threshold (more than 3 beetles per cluster or leaf). Avoid bag traps near vines.

Thin-skinned berries infested from veraison; rapid secondary breakdown. Spinosad or malathion application from first adult trap catch; harvest at optimal brix without delay.

Bark gnawed off canes at snow level in winter; girdled canes die back to the ground. Wrap canes with spiral tree guards or hardware cloth to snow-depth + 6 inches; remove covers in spring.