Grey bud weevil

The Grey bud weevil (Sciaphobus squalidus) is a species of beetle belonging to the family Curculionidae. It is a specialized pest that causes significant economic damage to commercial orchards, particularly during the early spring when fruit trees begin their active growth cycle.

The host plants for this pest include a wide range of fruit-bearing trees, such as apples, pears, cherries, and plums. The beetles specifically target the buds during the swelling and green bud stages, feeding on the tender internal tissues, which is critical as these buds contain the future flower and leaf structures.

The biological cycle of the Grey bud weevil spans two years. During the larval stage, the insect resides in the soil, feeding on the roots of various herbaceous weeds. Once the adult beetles emerge in early spring, they migrate upward along the tree trunks to reach the canopy, where they begin their feeding process.

The economic impact of this infestation is severe. Because the beetles destroy buds before they open, trees can suffer from complete defoliation or total fruit loss. In cases of high population density, entire branches or even whole trees may be left without any fruit production, leading to significant yield reduction.

Integrated Pest Management (IPM) is essential for controlling this beetle. Cultural practices, such as autumn soil cultivation to expose larvae to natural enemies and weather conditions, are highly effective. During spring, monitoring the population by shaking branches over a sheet is advised, followed by chemical intervention if the economic threshold is reached.

• Regular monitoring of tree canopy in early spring.
• Installation of sticky bands on tree trunks.
• Application of contact insecticides during the early bud burst stage.
• Removal of ground vegetation to restrict larval food sources.