Updating the geographic distribution of the protected hermit beetle Osmoderma italicum (Coleoptera: Scarabaeidae: Cetoniinae) in southern Italy

Osmoderma italicum Sparacio (2000) is a rare and localized saproxylic beetle (sometimes considered a subspecies of the widespread western European Osmoderma eremita Scopoli, 1783), currently known from a limited number of sites in southern Italy. Classified as Endangered according to The International Union for Conservation of Nature (IUCN) criteria B2ab(i,ii,iii); D, and listed under Annexes II and IV of the EU Habitats Directive, it is primarily associated with mature and old-growth forests that provide essential microhabitats such as hollow trees and decaying wood. This study presents an updated assessment of the O. italicum geographical distribution, ecological preferences, and altitudinal range in southern Italy, with a particular focus on the region of Calabria. The results indicate a broad but fragmented altitudinal distribution and highlight key habitat associations with tree species such as Fagus sylvatica, Quercus cerris, Q. petraea subsp. austrotyrrhenica, Q. pubescens, Castanea sativa, Alnus cordata, and Pinus heldreichii subsp. leucodermis. Citizen science data, combined with field surveys and Natura 2000 records, have contributed significantly to refining the known range of this taxon. Despite recent advances in data availability, critical knowledge gaps remain, particularly regarding population dynamics and habitat connectivity. We discuss current threats to the taxon and propose a set of conservation actions, including the protection of old-growth forest remnants, the promotion of deadwood retention in managed forests, and the integration of citizen science into long-term monitoring frameworks.