The Osmoderma species complex is here treated as five separate species (barnabita, eremita, cristinae, italica and lassallei), following Audisio et al. (2007, 2008). Distribution limits of these different forms remain poorly resolved, but for the purpose of these assessments, we follow the approximate distribution limits outlined in Audisio et al. (2007, 2008). There is ongoing debate as to whether or not these forms constitute valid species, but for the purpose of this assessment, we are assessing each form separately, following Bezděk (2016).

This obligate saproxylic species is bound to veteran hollow broad-leaved trees, mainly beeches and oaks, has a small extent of occurrence (EOO) of about 2,000 km² and potential area of occupancy (AOO) below 500 km². The population is considered severely fragmented into three parts considering the low dispersal ability of Osmoderma cristinae. Its AOO and habitat extent and quality are suspected to be declining as is, in general, the number of veteran trees with hollows. Moreover, regeneration of potentially suitable trees across the species' range is very slow with a progressing age gap: once the existing veteran trees have died, there will be no replacements in most areas. Even if efforts are made now to replant appropriate tree species, there may still be a gap of about a century during which time there would be very little suitable habitat available. Action is urgently needed to protect and appropriately manage existing veteran trees, as well as to ensure that suitable habitat continues to be available in future. Surveys and monitoring for this species are highly recommended and an action plan to be developed. The species is therefore assessed as Endangered under criterion B.

This species is only known from three sites in the Nebrodi Mountains and the Madonie Mountains of northern Sicily, Italy (Stoch 2003, Audisio et al. 2007, 2008; Bezděk 2016). Taxonomic status of this species has been recently confirmed both morphologically and genetically (Zauli et al. 2016). The potential EOO is about 2,000 km² considering the available habitat. Based on the estimated area of suitable habitat where this species has been recorded and can potentially be found, the potential AOO has been estimated below 500 km². The known localities correspond to three locations, each of them independently affected by the main threat of decline of the habitat extent and quality driven by forest fires and unsuitable forest management.

The population has not been quantitatively studied but it is considered to be very small and relatively stable. Osmoderma cristinae is known to develop only in a handful or veteran trees located in three separated sites with no habitat continuity between them, therefore it is severely fragmented considering the low dispersal abilities of this species.

This obligate saproxylic species inhabits old-growth broad-leaved woodlands in mountainous areas, although no information is available on the degree of canopy closure required. Larvae develop in large volumes of wood mould primarily derived from natural fungal decay of the dead heartwood in cavities at base of hollow living trees, mainly Fagus sylvatica and Quercus spp., usually their trunks and main boughs (Bellavista and Sparacio 2019, Sparacio and Viviano 2019).

This species is dependent on veteran hollow broad-leaved trees which are in continuous decline, including in the Madonie and Nebrodi mountains of Sicily. The main overall threat to this species is decline in extent and quality of the habitat caused by forest fires and logging. The restricted area occupied comprises a limited population size with reduced habitat availability, bird predation, fires, and unsuitable local techniques of forest management (Audisio et al. 2007). Illegal collection of specimens is also an ongoing threat to this species (Audisio et al. 2014). There is a decreasing number of hollow veteran trees in forest ecosystems usually caused by large- or small-scale commercial management. Increasing fragmentation of old-growth forests and lack of connection amongst the habitat trees is likely an ongoing threat. Exploitation from forestry is often a key immediate issue, but equally damaging are long-term changes in tree aging structure and an age-gap.

It is used for scientific research and monitoring. It appears in the international trade and is threatened by uncontrolled collecting of adults (Audisio et al. 2014).

It occurs in regional parks, e.g., Parco delle Nebrodi and Parco delle Madonie, although this does not necessarily guarantee effective protection of inhabited trees or appropriate habitat management. It is included in the Annexes II and IV of the European Habitats Directive (Trizzino et al. 2013) and Annex II of the Bern Convention, under the Osmoderma eremita complex. It is listed as Endangered B1ab(i,ii,iii)+2ab(i,ii,iii) in the Italian Red List of saproxylic beetles (Carpaneto et al. 2015). Action is urgently needed to protect and appropriately manage existing veteran trees, such as сщтештгу traditional pollarding, as well as to ensure that suitable habitat continuity to be available in future. Surveys and monitoring, as well as developing an action plan for this species are highly recommended.