Lyon weevil

Taxonomic position: The Lyon weevil (Otiorhynchus lugdunensis) belongs to the order Coleoptera and the family Curculionidae. These beetles are characterized by their nocturnal behavior and the fact that their larvae develop in the soil, making them significant underground pests that are often difficult to detect until substantial damage has occurred.

Host plants: This pest is a polyphage, meaning it feeds on a wide range of plants. It commonly affects berry crops like strawberries and raspberries, as well as various fruit trees and ornamental perennials. Its larvae are particularly destructive in nurseries, where they feed on the root systems of young, sensitive plants, leading to severe economic losses.

Biology and life cycle: The life cycle involves a complete metamorphosis. Adult weevils are flightless and nocturnal, hiding in the soil or under debris during the day. Females lay eggs in the soil near the root zone. Upon hatching, the larvae live underground, passing through several instars while consuming roots and the bark of the root collar, ultimately pupating within small earthen cells in the ground.

Damage and harmfulness: Damage occurs both above and below ground. Adults create characteristic notches along the edges of leaves. The larvae, however, cause the most severe harm by feeding on rootlets and girdling the main roots. This damage prevents the plant from absorbing water and nutrients efficiently, leading to wilting, stunted growth, secondary root rot infections, and often death.

• Deep cultivation of soil to disrupt larval development and expose them to predators.
• Nighttime manual collection of adult beetles using a flashlight.
• Application of entomopathogenic nematodes or fungi as biological control agents.
• Use of systemic insecticides applied to the soil or foliage when monitoring indicates high populations.
• Maintaining good sanitation by removing weeds that may provide alternative food sources for the weevil.