Blue leaf-rolling weevil

The blue leaf-rolling weevil (Temnocerus coeruleus) is a small beetle belonging to the family Attelabidae within the order Coleoptera. It is a recognized pest in temperate fruit orchards, characterized by a distinct metallic blue or greenish-blue coloration, and is known for its specialized feeding habits on reproductive parts of trees.

This pest primarily infests members of the Rosaceae family, including apple, pear, cherry, plum, and hawthorn trees. The weevil causes direct damage to buds, blossoms, and young fruitlets, which can significantly reduce the potential yield and impact the overall vitality of the orchard throughout the growing season.

The biological cycle begins in the spring when overwintering adults emerge from the soil as temperatures rise. After a period of feeding on emerging foliage and buds, the females deposit eggs into the fruitlets or petioles. They specifically girdle the stems, causing the tissue to wither and eventually drop, which creates an optimal environment for larval development.

Damage is often identified by the presence of scorched, wilting fruitlets or foliage still attached to the branches. The larvae develop inside these fallen or damaged materials. If not controlled, the continuous feeding activity can lead to premature fruit drop and may invite secondary infections by pathogens, further worsening the health of the tree.

Integrated pest management is essential for effective control. Cultural practices such as regular cultivation of the soil around the base of trees help disrupt the pupal stage. Additionally, meticulous sanitation—specifically the removal and destruction of infested fallen fruit—is critical. In cases of high population density, targeted application of contact or systemic insecticides during the pre-blossom stage is recommended.