Clay-coloured weevil

The Clay-coloured weevil (Otiorhynchus clavipes) is a member of the Curculionidae family, known for being a destructive pest in orchards, gardens, and greenhouses. This species is primarily nocturnal, making it difficult to observe during daylight hours when growers usually inspect their plants.

This pest has a wide host range, including various fruit trees, small fruits like strawberries and raspberries, and ornamental shrubs. The adult weevils cause visible damage by feeding on leaves and buds, while the soil-dwelling larvae are responsible for often fatal damage to the root systems of the plants.

The life cycle is primarily underground. Eggs are deposited in the soil near the host plant. Once hatched, the larvae consume roots, which inhibits nutrient uptake. After completing their development, they pupate in the soil before emerging as adults to feed on the foliage above ground and begin the cycle again.

Characteristic damage includes scalloped edges on leaves, which is a hallmark of many weevil species. Heavy infestations of larvae can lead to stunted growth, yellowing foliage, and the total collapse of the plant due to root destruction, particularly affecting nursery stock and young, vulnerable transplants.

Effective control requires an integrated approach. Cultural practices such as maintaining clean cultivation and rotating crops help minimize populations. Chemical control involves applying insecticides to the soil or foliage, often timed for night-time application when adults are active, or using biological agents like predatory nematodes to target the larvae.

• Monitoring for nocturnal feeding activity.
• Using sticky barriers on tree trunks to trap adults.
• Incorporating beneficial nematodes into the soil.
• Removing and destroying heavily infested plants.