Clay Coloured Weevil
(Otiorhynchus singularis)
Green Immigrant Leaf Weevil
(Polydrusus sericeus)
Strawberry Root Weevil
(Otiorhynchus ovatus)
Rough Strawberry Root Weevil
(Otiorhynchus rugosostriatus)
Black Vine Weevil
(Otiorhynchus sulcatus)
Obscure Weevil
(Sciopithes obscurus)
Damage: Larvae feed and girdle the roots and crown causing mature plants to decline. Young plants may be killed. Adult weevils feed on foliage resulting in ‘notching’, however, this does not usually affect the plant.
Insect: Adult weevils are wingless and have narrow snouts. They range in size from 5-12 mm, depending on species. Black vine weevil adults are the largest and can be up to 12 mm long. Rough strawberry root weevils are 8-10 mm long. Clay coloured and Obscure weevils are 7-9 mm long. The smallest is the Strawberry root weevil at 5-7 mm long. Each species is distinctly coloured. Green immigrant leaf weevil is shiny green and can fly.
Adult weevils climb the bushes to feed at night. During the day they rest near the soil surface and will play dead when disturbed. Clay coloured weevil adults chew buds, strip bark and girdle one year old wood from March to May. Leaf notching from June to September is normally caused by Black vine and Obscure weevil adults. Strawberry and Rough strawberry weevils tend to be more active in spring and fall, and remain protected in the soil during the hot summer months. Adult of Green immigrant leaf weevil make small feeding notches on newer leaves both high and low on the plant, and are active in fields during the day and evening. Larvae are up to 12 mm long, white with tan heads, and are found near the crown or roots of blueberry bushes. Larvae do not have legs, but are somewhat mobile in soil. Larvae hatch from July-September and spend the winter in the soil. Eggs are laid from spring to fall, with the peak occurring July-August.