Spruce bark tortrix

Systematic position: Cydia duplicana belongs to the order Lepidoptera and the family Tortricidae. It is recognized as a significant pest of coniferous trees, particularly spruce, known for its ability to damage the tree bark and cambium layers.

Host plants: The pest primarily targets Picea species (spruce), with Norway spruce being the most common host. The insect is typically found in mature stands or in plantations where trees have minor mechanical wounds, as it prefers to colonize areas with damaged bark.

Biology and life cycle: The species typically completes one generation per year. Adults emerge in late spring or early summer to mate and lay eggs. Larvae hatch and immediately bore into the bark, constructing galleries where they feed and overwinter. Pupation occurs within these galleries in the following spring before the emergence of the next generation of moths.

Damage and harm: The larval feeding activity destroys the cambium, which interferes with nutrient transport. Key symptoms include resin flow at the site of infestation, localized bark necrosis, and the yellowing or browning of needles on affected branches. Severe infestations can lead to top-kill or the death of the entire tree.

Control measures: Effective management relies on integrated approaches. Silvicultural practices, such as removing infested material and maintaining tree vigor, are paramount. Chemical control using systemic insecticides is generally reserved for nurseries or high-value landscapes and must be timed correctly according to monitoring data obtained from pheromone traps.