Abstract

Saproxylic beetles are sensitive indicators of forest integrity, and many can be efficiently sampled using synthetic pheromone lures, yet the joint roles of local habitat and broad-­scale geography in structuring beetle communities attracted to pheromone-­baited traps remain unclear. We deployed a six-­component cerambycid pheromone blend and an Elater ferrugineus (Linnaeus, 1758) (Coleoptera: Elateridae) pheromone lure in funnel traps at 39 forest sites spanning approximately 600 km north–south and approximately 400 km east–west in southern Sweden during 2023–2024. Traps captured 1791 individuals of 58 species, including seven Swedish Red-­listed taxa and Tetropium fuscum (Fabricius, 1787) (Coleoptera: Cerambycidae), a quarantine target in North America. Negative binomial models, applied to 21 species (present at ≥ 5 sites), revealed that forest-­cover effects were frequently contingent on geography: five species showed latitude × forest interactions, and two showed longitude × forest interactions; positive forest effects were generally strongest in the south and diminished or reversed northward; longitudinal patterns were species-­specific. Latitude or longitude alone explained abundance patterns in six further species, whereas forest cover had a stand-­alone effect in only one species. Pheromone-­baited trapping of multiple beetle species therefore provides an efficient dual-­purpose tool, simultaneously informing Red List assessments and early pest detection, whilst demonstrating that the conservation benefits of increasing forest cover depend on the regional climate context.

Keywords

biosecurity, Cerambycidae, chemical ecology, dead wood, Elateridae, forest ecology, Red List

Fulltext

Landscape and Geography Determine Saproxylic Beetle Captures in Pheromone-­Baited Traps