Guidelines for the monitoring of Osmoderma eremita and closely related species

Abstract

Osmoderma eremita (Scopoli, 1763) is a saproxylic scarab beetle protected by the Habitats Directive in the European Union. The present paper is part of a special issue on monitoring of saproxylic beetles protected in Europe and starts with a revision of the current knowledge on systematics, ecology, ethology and conservation of O. eremita and its allied species, followed by experimental tests of different methods for monitoring its populations. Two methods were compared in several localities of central Italy: (1) the widely used pitfall traps into tree cavities and (2) black cross windows traps baited with a specific pheromone produced by male beetles. The first method, often used in northern and central Europe, did not give acceptable results in Italy probably because of the scarcity of veteran trees with large hollows. It could only be used successfully in areas where: 1) tree hollows were abundant, large enough and with sufficient amounts of wood mould for planting pitfall traps and 2) the team is composed of several operators in order to ensure the checking of at least 150 traps every two days during the whole period of mating activities (15 July-25 August). The second method, consisting of hanging 30 black cross window traps during the mating period and checking them every two days, turned out to be better for capturing a significant number of individuals but cannot be used every year because of the possible disturbance on mating activities of the species. CONSERVATION IN PRACTICE Launched to accelerate biodiversity conservation A peer-reviewed open-access journalEmanuela Maurizi et al. / Nature Conservation 20: 79-128 (2017) 80

Mapping analysis of saproxylic Natura 2000 beetles (Coleoptera) from the Prigoria-Bengeşti Protected Area (ROSCI0359) in Gorj County (Romania)

“…Most of the adult individuals remain within a few hundreds of metres of their natal tree (Chiari et al, 2013). The main threats recognised are the decreasing number of hollow old trees in forests, fragmentation of old-growth forests and lack of connection amongst the habitat trees (Chiari et al, 2013;Maurizi et al, 2017).…”

Analyses of occurrence data of protected insect species collected by citizens in Italy

“…The species is presented in detail (biology, ecology and monitoring methods) by Maurizi et al (2017).…”

Training of a dog for the monitoring of Osmoderma eremita

“…All of these characteristics fit well with the O. eremita study case. Indeed, without the aid of a dog, most of the sampling methods commonly used to detect (and monitor) the hermit beetles involve wood mould sampling (Ranius et al 2005, Chiari et al 2014) and passive or active traps (Ranius 2001, Svensson and Larsson 2008, Chiari et al 2013, Maurizi et al 2017, which are characterised by the disadvantages listed above. Locating larvae inside trunks using wood mould sampling is the main method which allows the identification of breeding sites of hermit beetles and other saproxylic insects.…”

“…This species is associated with old hollow broad-leaved trees in mature forest ecosystems, as well as outside closed forests (e.g. pasture woodlands) (Ranius et al 2005, Giangregorio et al 2015, Maurizi et al 2017.…”

“…Searching for larvae has some additional advantages as adults have a short period of activity (Maurizi et al 2017) and population size of adults fluctuates during the activity period and in correlation with environmental factors. In contrast, larvae are always present inside hollow trees during their development which lasts about 3 years.…”