Ireland

The cabbage seedpod weevil

Ceutorhynchus assimilis

Description

Adult weevils are ash-grey and approximately 3 to 4 mm (1/6 inch) long. They have a prominent curved snout that is typical of most weevils. Larvae are white and grub-like, without legs or eyes. Soon after hatching, the larvae begin feeding within the pods on developing seeds.

Crop damage from cabbage seedpod weevil can occur in several ways. When flower buds develop on canola plants, adults feed on the buds, causing bud-blasting and reduced yield potential in dry years, when the ability of plants to compensate is limited. Larvae feed within developing pods with each larva consuming about five seeds during its development. Although this amount represents only 15 to 20 per cent of the total yield of a particular pod, these pods are predisposed to premature shattering.