First record of the bark beetle Hylastes cunicularius Erichson, 1836 (Coleoptera: Curculionidae: Scolytinae) reproducing successfully in Iceland

Bark beetles (Curculionidae: Scolytinae) are among the most damaging pests in forest ecosystems worldwide, but have never been previously recorded in the Icelandic natural environment. We investigated the presence of bark beetles by using pitfall traps in one area (Mógilsá) and searched for potential damage signs in three other forested areas (Heiðmörk, Fossvogsdalur and Öskjuhlíð) in the Reykjavík region over the summers of 2024 and 2025. Bark beetles and signs of them were found in all four forest areas investigated. A total of 159 individuals (adults, larvae, and pupae) were collected. DNA analysis confirmed species identity to be Hylastes cunicularius. A total of 72 adults were captured in pitfall traps throughout the season, with peaks in May 2025 and June 2024. Larval galleries and pupae in Picea logs confirmed successful reproduction and establishment of the species. H. cunicularius establishment in Iceland raises concerns about potential ecological and economic effects, especially in young conifer stands. Ongoing monitoring in other nearby conifer-dominated forests is recommended to evaluate population growth, potential spread, and related risks to Icelandic forests.