Monitoring of three Saproxylic Beetles (Cerambyx cerdo, Osmoderma eremita, Rosalia alpina) in South Tyrol: Population Status and Habitat Management.

In this study we present the results of monitoring several important populations ofthree protected saproxylic beetles: Cerambyx cerdo, Osmoderma eremita, and Rosaliaalpina. These three species are of special interest since their occurrence denotes thepresence of old trees and near natural forests.Cerambyx cerdo and Osmoderma eremita were monitored at one site with species-specificstandardised sampling techniques (visual survey transects, pheromone, and bait traps).Capture-mark-recapture techniques were employed. However, the low number ofrecaptures did not allow for a reliable estimate of population size for these species.Furthermore, additional new occurrences were confirmed, expanding the local knowndistribution.Finally, a target monitoring on a newly discovered population of Rosalia alpina involvedsurveys of newly placed beech logs and the surrounding natural habitats. This monitoringresulted in 79 individuals counted with 21 recaptures. Using the individualpatternson the elytra, an open population model for capture–mark–recapture (POPANanalysis) was used to estimate a local population of 171 adult individuals.This study sums up the methods, results and conclusions of coordinated surveys andmonitoring of saproxylic beetles from 2023 to 2025 and underlines the need and potentialfor long-term monitoring to inform targeted habitat management and conservation.