The important wingless weevils in the UK are members of the beetle group belonging to the genus Otiorhynchus. Within this genus, at least three are important pests of soft fruit in the UK. They are the vine weevil (Otiorhynchus sulcatus), a clay-colored weevil (O. singular) and the strawberry weevil (O. ovatus).
The first two weevils are particularly important in northern Britain. There have been recent reports of exotic wingless weevils being found in several parts of the UK (Barclay MVL, The Coleopterist 12(2): 41-56, 2003). Otiorhynchus armadillo and O. salicicola are two European wingless weevils that have become established in Britain.
One species, O. armadillo, is a known pest of raspberry in northern Italy and is a cause for concern. Fortunately, as yet, there are no reports of this weevil in commercial raspberry plantations in the UK. The image above shows adult vine weevil (Left) and clay-colored weevil (Right). (Click on image to enlarge).
The vine weevil (Otiorhynchus sulcatus) is a known pest of raspberry in most temperate parts of the world. In the Pacific North-Western States of the USA, it is a major contaminant of machine-harvested raspberry.
In the UK, they are an increasing problem in raspberry crops. Increasing vine weevil numbers over the past 30 years have been attributed to a reduction in the number of insecticides available for control and an increase in container potted plants and polythene mulches.
The image on left is an adult female vine weevil on a raspberry leaf (click on image to enlarge)
Adult vine weevils have been reported to feed on more than 100 different plant species. The insects feed on leaves in a characteristic notching pattern. Larvae of the vine weevil attack plant root, which decreases plant development and production. Many plant species die when attacked by vine weevil larvae.
In soft fruit, raspberry plants can tolerate moderate infestation whilst low numbers of larvae can kill young strawberry and blackcurrant plants. In raspberry, adult weevils shelter in the foliage during the day and can be dislodged during harvest resulting in contaminated crops.