Pine weevil

The pine weevil (Pissodes cembrae) is a significant forest pest belonging to the Curculionidae family within the order Coleoptera. This species is notorious for causing substantial damage to coniferous forests, primarily affecting the growth and vitality of young and middle-aged stands.

This pest mainly infests various species of the Pinaceae family, with a clear preference for stone pines (cembra), Scots pine, larch, and occasionally spruce. It is particularly drawn to trees that are already physiologically stressed by drought, soil compaction, or previous defoliation, though healthy stands can also be colonized during population outbreaks.

The life cycle of Pissodes cembrae involves four distinct stages: egg, larva, pupa, and adult. Adults typically emerge in the spring to feed on the bark of young twigs, causing localized damage. Females then deposit eggs into the bark of trunks or thick branches, where the emerging larvae feed on the cambium and inner bark, effectively girdling the tree.

Infestation symptoms include small round entrance holes in the bark, accompanied by resin bleeding (resinosis). As the larvae consume the phloem, the tree’s nutrient supply is disrupted, leading to crown yellowing, wilting, and eventually dieback. Large-scale infestations can cause the death of entire stands, leading to significant economic losses in silviculture.

Integrated pest management (IPM) is essential for controlling this beetle. Key strategies include the prompt removal and destruction of infested timber to prevent the emergence of new adults, the use of trap trees, and regular monitoring using pheromone traps. In high-value ornamental or nursery settings, targeted applications of systemic or contact insecticides during the adult flight period can provide effective suppression.