Impressed weevil

The impressed weevil (Otiorhynchus impressiventris) is a significant pest belonging to the order Coleoptera and the family Curculionidae. Known for its cryptic behavior, this beetle poses a substantial threat to commercial fruit production, nurseries, and ornamental gardening by attacking both underground and aerial parts of host plants.

Host plants include a variety of species, most notably strawberries, raspberries, vines, and numerous fruit trees. The larvae are primarily root feeders, causing damage that often results in the stunted growth or death of the host. In contrast, the adult weevils feed on the foliage, typically consuming the edges of leaves and creating characteristic notches.

The biological cycle of this species involves overwintering as larvae within the soil profile. As temperatures rise in spring, the larvae resume feeding on root systems before pupating in earthen cells. Adult emergence typically occurs in late spring or early summer. These adults are nocturnal, which makes their detection and control during the daylight hours more challenging for growers.

Economic damage is twofold: foliage consumption by adults reduces the photosynthetic capacity of the plant, while severe root pruning by larvae disrupts water and nutrient uptake. If left unmanaged, infestation levels can reach critical thresholds, particularly in perennial crops where the soil remains undisturbed for several years, providing an ideal environment for population buildup.

Integrated Pest Management (IPM) strategies are essential for effective control of this weevil. Successful management programs typically incorporate the following practices:

• Mechanical cultivation of soil during the pupation stage to destroy larval chambers.
• Application of soil-applied insecticides during periods of peak larval activity.
• Use of nocturnal foliar sprays to target adult weevils as they emerge to feed.
• Implementation of biological control agents, such as entomopathogenic nematodes.
• Maintaining clean fields by removing weed hosts that harbor the adult populations.