Grape Curculio: Appearance, Territory, Damage and Life Cycle

Latin Name: Craponius Inaequalis

Appearance: The grape curculio, Craponius Inaequalis, is a species of minute seed weevil in the beetle family Curculionidae. It is native to North America. Grape curculio adults are 3 mm length and 2.5 mm broad reddish-black snout weevils. Larvae are legless, yellowish-white, and have brown heads.

Hosts Plants: Grapes

Territory: North America

Damage Insect Cause: Adults feed on grape foliage, leaving a distinctive zig-zag pattern on the undersides of leaves and fruit petioles. They also cause fruit damage by puncturing berries with their snouts before depositing eggs. Larvae inflict significant harm by feeding on pulp and seeds inside the berries. Curculio density can be reduced by good orchard cleanliness, including a thorough clean-up of leaf debris and rotting berries beneath the vines. Insecticides must be sprayed anytime insects or damage are present.

Life History and Habits: Adults overwinter in ground debris in and near vineyards. They emerge from hibernation in the spring and attack the fruit approximately 25 days later. Each female will oviposit in one to fourteen berries every day, and egg laying will last an average of 78 days. Larvae graze for 12 days before emerging from the berries to pupate in the earth. Pupae have a lifespan of 19 days. Adults appear in late summer and feed on grape leaves. These adults hibernate. Each year, one generation is born.