Vine Weevil
Vine Weevil Facts
Common name: Vine Weevil.
Scientific name: Otiorhynchus Sulcatus.
Vine Weevil feed on some fruits and ornamental plants; particularly any grown in pots and containers.
Vine Weevils are active from spring to late summer with grubs being active from summer to spring.
Symptoms include:
- Adult Vine Weevils notch leaf margins (edges)
- Grubs eat the roots
Weevils are a group of several families of beetles in the superfamily Curculionoidea, there are more than 500 species in the UK.
Non-Chemical Treatments can include:
- Pick off adults in the evenings, shake off shrubs and check in pots and containers; underneath too
- Add sticky barriers to prevent access
- Encourage predators like frogs, birds and ground beetles
- Remove larvae/eggs from the soil
The Vine Weevil is native to Northern Europe but was seen in North America as early as 1835 so it has now spread around many parts of the world. It has a few weaknesses in its lifecycle and the recent popularity of growing plants in pots has enabled it to flourish.
About Vine Weevils
Vine Weevil Lifecycle
Black vine weevils develop through four life stages; egg, larva, pupa, and adult. Overwintering is primarily as late instars (older larvae) or prepupae. A few may overwinter as adults. Weevils overwintering as late instars pupate in late winter through to spring.
Adult Weevils emerge in spring and feed on the foliage of host plants, mostly nocturnal. Adults do not fly, but may walk to new plantings from nearby infested plants, ornamentals, and unmanaged vegetation. Peak adult populations and leaf chewing occur in summer and early autumn.
Female Weevils feed for several weeks before laying eggs. About 4 weeks after adults emerge and begin eating the foliage, eggs are laid in soil near the base of plants. A single female can lay as many as 500 eggs. Eggs hatch into larvae that develop through 6, increasingly larger instars as they feed underground over a period of 8 to 10 months. There is generally 1 generation per year.
Vine weevils (Otiorhyncus Sulcatus) are brown-black insects, approximately 1cm long, with jointed antennae and pale-brown flecks on their backs. Like aphids, the females do not need males to reproduce, so it only takes one Weevil to start an infestation. The larvae are plump, off-white and maggot-like, up to 9mm long. They are usually seen curled in a C-shape, with brown heads and no legs.
There are other similar Weevils that do much the same sort of damage. Clay-coloured Weevils (O. Singularis) eat leaves, and their maggots gnaw the roots and bark of woody plants. They are hard to distinguish from Vine Weevils, but they are dealt with in the same way.
