Black Vine Weevil
Otiorhynchus sulcatus
Black Vine Weevil, Snout Beetle, Kalander (Afr.), Snuitkewer (Afr.)
Otiorhynchus sulcatus 23-8-2007 20-10-41
by Opuntia. CC BY-SA 3.0
A Vine Weevil is a beetle that feeds off of a broad range of plants, both indoors and out; but these beetles have the biggest impact on container plants.
Adult beetles are most active in spring and summer eating leaves at night. The grubs are most active during autumn and winter, where they feed invasively on the plant roots.
If root infestations are particularly heavy, the plant will quickly lose vigour. Young plants in containers are most likely to die from a Vine Weevil infestation.
Traits

Grubs eat plant roots resulting in wilting plant death.

Vine weevil eggs are a source of food for soil-dwelling insects.
Appearance
Adults: The adult weevil is a dark black, matte colour and have fused wing covers so are unable to fly. They have six legs and two long antennas on their head. They're nocturnal, so they come out at night to feed on the outer parts of leaves. They have elongate heads, with a 'snout'.
Larvae: Small, slightly curved and are creamy-white with light brown heads that measure around 10mm in length. They are located on the roots.
Pupae: Currently unavailable.
Eggs: The eggs are so tiny you need a hand lens to see them.
Symptoms
You may see irregular notches in your leaf margins during the summer months.
Small, black beetles on leaves at night.
Sudden wilting of plants in autumn and winter.
Numerous creamy-white grubs around the roots of plants.
Activity
Nocturnal
Personality
Order
Coleoptera
Family
Curculionidae
Metamorphosis
Complete
Distribution
Central Europe, including the UK
Biological treatment
Unfortunately, few treatments can eliminate this pest because they burrow within the roots of host plants.
It's important to note that Weevils are nocturnal, so you're not going to catch them in the daytime. If you find irregular notches in the leaf margins, you may want to attempt a few evening torch checks.
Check on and under the leaves and fruits of plants.
It's thought that good housekeeping, such as practising: mulching, re-hilling, field sanitation, crop rotation and using clean planting material, can significantly reduce the severity of an infestation.
Pheromone traps can be used to monitor pest populations in the garden. Sticky barriers can also be effective around the base of ornamental plants and shrubs.
Likewise, diatomaceous earth dusted over leaves and around the bases of plants can kill Weevils. Be careful during application, as this stuff is nasty if inhaled and can be extremely irritable when in contact with the eyes.
Nematodes can be used and introduced to the soils of your plants, and you can buy these from some garden centres or online. You can use them in both containers or open ground. By using nematodes such as Steinernema kraussei, you can help to reduce any grubs that are in the soil. These should be applied from August to early September for the best results, as larvae will be smaller in size and not have caused too much damage already. Always read instructions before application.
Chemical treatment
Currently unavailable
Attracts
Ornamental plants and fruit plants, in particular vines, Primula, Rhododendron, Heuchera, Cyclamen and strawberries.
Primula
Primula spp.
Coral Flower
Heuchera spp.
Hosta
Hosta spp.
Strawberry
Fragaria spp.
Cyclamen
Cyclamen spp.
Rhododendron
Rhododendron spp.
Astilbe
Astilbe arendsii 'Astary'
Common Camellia
Camellia japonica
Bachelor's Buttons
Craspedia uniflora
Garden Rhubarb
Rheum × hybridum
European Gooseberry
Ribes uva-crispa
Redcurrant
Ribes rubrum
Blackcurrant
Ribes nigrum
White-Spathed Jack In The Pulpit
Arisaema candidissimum
Compact Winged Spindle Tree
Euonymus alatus 'Compactus'
Varigated Box Elder 'Elegans'
Acer negundo 'Elegans'
English Yew
Taxus baccata
Calico Bush
Kalmia latifolia 'Freckles'
Geelblom
Cineraria saxifraga
Lilac
Syringa vulgaris
Auricula
Primula auricula
Evergreen Bittersweet
Euonymus fortunei
Repels
Place any grubs found on perches for garden birds to feast.