What's eating my canadice grape?

Canadice is a seedless table grape susceptible to Japanese beetle, grape berry moth, and spotted wing drosophila, which damages the thin-skinned berries near harvest. Birds are a serious and consistent threat to ripe clusters. Grape phylloxera affects roots but American Vitis labrusca rootstocks have some natural resistance. Bird netting is non-negotiable for a decent harvest.

Entire clusters stripped or individual berries pecked and hollowed; damage accelerates rapidly once birds locate ripe fruit. Cover vines with fine-mesh bird netting well before berries color; use reflective tape or predator decoys as supplementary deterrents.

Skeletonized leaves with only veins remaining; adults aggregate heavily on grapevines from late June into August. Hand-pick into soapy water each morning; apply neem oil or pyrethrin; introduce milky spore (Paenibacillus popilliae) to lawn soil for long-term grub control.

Larvae bore into developing berries, causing shriveling and entry points for bunch rot; infested berries have small entry holes and webbing. Apply Bt kurstaki or spinosad at egg hatch (monitored with degree-day models); use pheromone mating disruption in larger plantings; remove mummified fruit.

Females lay eggs inside ripening thin-skinned berries; larvae cause berry collapse and secondary fungal rot near harvest. Monitor with cider vinegar + dish soap traps; harvest promptly at ripeness; apply spinosad early morning before beneficial insects are active.