Black vine weevil

Otiorhynchus sulcatus

1. Identification

• Common name: Black vine weevil
• Scientific name: Otiorhynchus sulcatus Fabricius
• Order: Coleoptera
• Family: Curculionidae

2. Pest description

• Adults: Weevils 8–12 mm long, with a robust, black body bearing pale scales that form irregular patches; a short rostrum and geniculate antennae; unable to fly; nocturnal activity.
• Larvae: Apodous, whitish, with a curved body and a brown head; they develop in the soil, feeding on the roots.
• Pupae: Formed in the soil, in earthen chambers.
• Eggs: Laid in the soil, near the collar of the plants.

3. Main hosts

• Grapevine.
• Numerous ornamentals and shrubs, including Rhododendron spp., Camellia spp., Taxus spp., Azalea spp., Fragaria spp. and other cultivated species.
• An important polyphagous pest in nurseries and gardens.

4. Symptoms and damage

• Adults feed on the leaves, producing characteristic semicircular notches on the margins.
• Larvae feed on the roots, causing necrosis, loss of vigour and wilting.
• Young plants may die owing to the destruction of the root system.
• In grapevine, the most significant damage occurs in young or weakened plants.
• In ornamentals, it can cause significant losses in nurseries.

5. Biological cycle

• One generation per year, which may be prolonged in colder climates.
• Adults emerge in spring and summer, feeding on the leaves before egg-laying.
• Eggs laid in the soil; larvae develop over several months, feeding on the roots.
• Pupation in the soil; adults overwinter or remain inactive in shelters.
• Development favoured by moist soils and the presence of dense vegetation.

6. Monitoring

• Observation of semicircular notches on the leaves, typical of adult feeding.
• Inspection of the root system of weakened plants for the detection of larvae.
• Refuge traps (boards, cardboard rolls, foliage) with pheromone for the detection of nocturnal adults.
• Reinforced monitoring in nurseries, greenhouses and young plantations.

7. Management measures

• Cultural: Removal of debris and shelters; surface tillage of the soil to expose larvae and pupae; elimination of heavily affected plants; use of certified, healthy plants.
• Preventive: Reduction of excessive humidity; avoid high densities; regular inspection of ornamental and nursery plants; use of physical barriers or refuge traps to capture adults; avoid transplanting during periods of high adult activity.
• Integrated protection: Regular monitoring; intervention only when necessary; practices that reduce the survival of larvae in the soil and the presence of shelters for adults.

Bibliographic references

• EPPO Global Database – Otiorhynchus sulcatus.
• CABI Invasive Species Compendium – Otiorhynchus sulcatus.
• Moorhouse, E. R. et al. (1992). Biology and control of Otiorhynchus sulcatus.
• Alford, D. V. (2014). Pests of ornamental trees and shrubs.