Osmoderma eremita ( Coleoptera , Scarabaeidae , Cetoniinae ) in Europe

Osmoderma eremita (Coleoptera, Scarabaeidae, Cetoniinae) in Europe.— Research, monitoring and development of preservation strategies for threatened species are often limited by national borders even though a global perspective would be more appropriate. In this study, we collected data on the occurrence of a threatened beetle, Osmoderma eremita, associated with tree hollows in 2,142 localities from 33 countries in Europe where it is or has been present. The larvae develop in tree hollows and very few observations of larvae have been observed in dead logs on the ground. As long as there is a suitable tree hollow, it appears that O. eremita may use any tree species. Oaks (Quercus spp.) are the trees mainly used by O. eremita, followed by lime (Tilia spp.), willow (Salix spp.), beech (Fagus sylvatica) and fruit trees (Prunus spp., Pyrus spp., Malus domestica). O. eremita is still found in some remnants of natural forest, but is mainly observed on land that has long been used by man, such as pasture woodlands, hunting parks, avenues, city parks and trees around agricultural fields and along streams. The occurrence of O. eremita seems to have decreased in all European countries. Relatively high densities of O. eremita localities occur in Central Europe (northern Italy, Austria, Czechia, southern Poland and eastern Germany), some parts of Northern Europe (south–eastern Sweden, Latvia) and France. In some regions in north–western Europe, the species is extinct or may occur at some single sites (Norway, Danish mainland, The Netherlands, Belgium, north–eastern France). There are few data from south–eastern Europe. Many local extinctions of O. eremita are to be expected in the near future, especially in regions with recent habitat loss and fragmentation. O. eremita is useful as an indicator and umbrella species for the preservation of the entire invertebrate community associated with hollow trees in Europe. A preservation plan for O. eremita should include three aspects that are of general importance in nature conservation in Europe today: (1) preservation of remnants of natural forests with old, broad–leaved trees, (2) preservation and restoration of habitats related to traditional agricultural landscapes and (3) preservation of remaining "islands" of nature in urban areas.


Introduction
In temperate and Mediterranean regions of Europe, old trees are now scarce and many species dependent on this habitat seem to be confined to small remnants with no possibility for dispersal between the populations (e.g.Harding & Rose, 1986;Speight, 1989).This is because old-growth deciduous forests have declined to a very small proportion of their original extent (Hannah et al., 1995).Up until the nineteenth century, old trees were also widespread in pasture woodlands and wooded meadows, but abandoned management and changes of land use have severely reduced these habitats (e.g.Nilsson, 1997;Kirby & Watkins, 1998).
When trees age, hollows with wood mould often form in the trunks.Wood mould is loose wood colonised by fungi, often with remains from bird nests and insects.Trunk hollows with wood mould harbour a specialised fauna mainly consisting of beetles, flies, mites, pseudoscorpions and ants.Many invertebrate species associated with hollow trees are threatened (e.g.Ehnström & Waldén, 1986;Warren & Key, 1991), and therefore the protection of this fauna should be an important goal for nature conservation in Europe.
A strategy for nature conservation should be based on knowledge about which sites should be given priority.Which habitat types are most valuable for invertebrates living in tree hollows?How are these habitats distributed in Europe?As neither time, economical resources or taxonomic expertise are available to carry out detailed surveys of saproxylic invertebrates throughout Europe, we need to find surrogates that provide clues about the conservation values but are easier to survey.One possibility is to measure the amount of habitat (in this case, large or hollow trees), while another is to survey indicator species.Surveys of old trees have been conducted with different protocols in Britain (e.g.Clifton, 2000) and Sweden (e.g.Hultengren & Nitare, 1999;Ranius et al., 2001).Lists with saproxylic insects that may be used as indicators have been compiled by Speight (1989), Rundlöf & Nilsson (1995) and Nilsson et al. (2001).One weak point with these surrogates is that they have usually been developed based on personal experience from a restricted region; the lists of indicator species and suggested methods to survey old trees are adopted to the researcher's study area, and do not necessarily suit the whole of Europe.Another problem is that to count all hollow and large trees (as in Ranius et al., 2001) or to survey presence or absence of tens of saproxylic insect species (as in Rundlöf & Nilsson, 1995;Nilsson et al., 2001) is expensive and timeconsuming.It will therefore take a long time until there are sufficient data of this kind to allow comparisons between different parts of Europe.
A simple measure of conservation values could be achieved by collecting data about the presence of a single species.One beetle species, Osmoderma eremita (Scopoli, 1763;Coleoptera: Cetoniidae), has been more studied in ecological research than any other invertebrate species associated with tree hollows (see Ranius, 2002b, for a review).This species has a high priority according to the European Union's Habitats Directive (Luce, 1996), and has therefore been surveyed in many countries in recent years.It is also listed by the Bern convention.A study in south-eastern Sweden showed that in sites with tree hollows, those with O. eremita present have a higher species richness of other threatened beetle species associated with tree hollows (Ranius, 2002a).The fact that this species is easy to survey also improves its suitability as an indicator species (Ranius & Jansson, 2002).
In this paper we compile data on the occurrence of O. eremita in Europe.It is written by 28 co-authors each responsible for one or more European countries.Information has been compiled from museums and private collections, literature and field surveys.The paper is based on a private initiative, based on the belief that entomology and nature conservation would do better with stronger co-operation between conservationists from all European countries.

Taxonomy
Osmoderma species occur in northern America, Europe, Turkey, south-eastern Siberia, north-eastern China, Korea and Japan (Shaffrath, 2003a).Taxonomists's opinions differ about the forms of Osmoderma in Europe.According to Tauzin (1994aTauzin ( , 1994bTauzin ( , 1996Tauzin ( , 2002)), there are two Osmoderma species in Europe: O. eremita (Scopoli) in Western Europe and O. lassallei Baraud & Tauzin in Eastern Europe.Sparacio (1994) described a third species, O. cristinae, endemic for Sicily.Later, Krell (1996) treated these three European forms of Osmoderma as different subspecies of O. eremita.However, in a recent review of the European Osmoderma, Sparacio (2001) considered again both O. lassallei and O. cristinae as distinct species, and described a fourth possible separate species of this complex, O. italica (recently emended O. italicum by Audisio et al., 2003), considered endemic to the southern mainland of Italy.A new, but partly questionable, nomenclatorial and taxonomic scenario of the European Osmaderma was finally recently introduced by Gusakov (2002).An ongoing genetic study by P. Audisio and coll., based on comparison of mtDNA genes sequences, will probably provide greater insight in the taxonomy of the species complex.For simplicity, in this paper we do not distinguish between Osmoderma forms, but provisionally apply the name O. eremita to all Osmoderma in Europe.

Life history
Normally, the adults of O. eremita are found from July to September, but in some regions (Germany, Slovenia and Italy) there have been several observations in June and even a few in April and May (Stegner, 2002;Schaffrath, 2003a;P. Audisio, pers. obs.;G. Carpaneto, pers. obs.;A. Pirnat, pers. obs.).
The adults normally die in autumn; nevertheless, a hibernating adult female has once been found in January in the forest of Fontainebleau, France (Tauzin, 1994b).When rearing the species in the laboratory, Tauzin (1994b) observed adult males to have a lifetime of 10-20 days, while females lived for more than 90 days.Schaffrath (2003a) fed isolated males which reached lifetimes of 90 days.In a field study in Sweden, males and females seemed to have the same life-time, with a maximum of about one month (Ranius, 2001).
During a research project conducted over several years in Sweden, O. eremita was only found active at daytime (T.Ranius, pers. obs.), while in Russia, active adults have also been observed at dusk and night time (N.Nikitsky, pers. obs.) and in Germany and France at dawn (Schaffrath, 2003a;Stegner, 2002).Flying individuals have mainly been seen in the early afternoon on warm, sunny days.
According to Luce (1996), O. eremita females lay 20-80 eggs.When Jönsson (2003) reared the beetle in the laboratory, he searched for larvae one-two months after the eggs were laid, and found 12-18 larvae produced by each female.Egg incubation lasts 14-20 days: initially the eggs are dull white, they then become yellowish and redouble their size, up to a diameter of 5 mm.First instar larvae have a length of 6 mm, but at complete development they can reach 60 mm and have a weight of more than 12 g (Schaffrath, 2003a).Before metamorphosis, the larvae construct an oval cocoon made of their excrements and wood mould (Tauzin, 1994b).From laboratory studies, we know that cocoons are made in autumn (September), but metamorphosis takes place in the following spring (May-June) (Tauzin, 1994b).However, in Italy, D. Baratelli (pers. comm.)observed that two larvae found in February developed into adults in April and May of the same year.
In laboratory and field studies in Poland, Pawłowski (1961) found the generation time to be three or four years.The larval feeding period was between 65 and 93 weeks.Feeding activity took place when the average daily temperature exceeded 13°C, which means that in Poland the larvae are active about 30 weeks per year.Developing time and hibernation depend on the temperature of the wood mould, which varies between years and localities.In Germany, Russia and Latvia, the development time in the field is also usually either three or four years (Nikitsky et al., 1996;Schaffrath, 2003a;D. Telnov, pers. obs.).
The population size varies widely between trees (Ranius, 2001).In an area in southeastern Sweden there were, on average, 11 adult beetles per hollow oak and year (Ranius, 2001), and a similar population size per tree has been reported from Hallands Väderö, southwestern Sweden (Jönsson, 2003).At both these sites, there were almost 100 adult beetles per year in some trees.Circumstantial records suggest that the population size per tree is of the same magnitude in other parts of Europe.For instance, in chestnut and willow trees in Lovero Valtellino (Lombardia, Italy) normally 5 to 30, but sometimes more, individuals per tree were observed (P.Audisio, pers. obs.).Also in Latvia, oaks and lime trees have been found harbouring populations of the same magnitude (D.Telnov & F. Savich, pers. obs.).Schaffrath (2003b) counted the larvae and cocoons in three oaks and one beech in Germany and found 30-120 individuals, which implied that there was about one larva per litre of wood mould.In France, Prunier (1999) counted the larvae in the trunk of an old oak from 1 to 7 m from the ground and found more than 150 larvae.
Males of O. eremita emit a characteristic odour that French entomologists have called "odeur de prune" (= odour of plums) or "odeur de cuir de Russie" (= odour of Russian hide) (Tauzin, 1994b).German entomologists have called the beetle "Aprikosenkäfer" because it smells like apricots (Eisenach, 1883), even though "Eremit" and "Juchtenkäfer" (from Juchtenleder = Russian hide) are more commonly used names.The odour can be perceived by humans several metres from the beetle.Chemical analyses have revealed that the males emit the same compound (a decalactone) that is emitted by apricots and plums, and that the compound works as a pheromone that attracts female O. eremita (Larsson et al., 2003).
Only on a few occasions have O. eremita adults been seen feeding.In Croatia, B. Gjurašin has collected O. eremita adults on flowers (Leucanthemum sp. and Viburnum sp.) on two occasions, and in Spain, there has been a sighting on flowers of Sambucus nigra (L.O. Aguado, pers.obs.).From Germany, M. Bahn (Schnitter in litt.) has reported two specimens from umbelliferous plants.Schaffrath (2003a) has collected a few reports of observations from flowers and sap flows.In Poland, Russia and Estonia, the beetle has been observed feeding on sap flows (Tenenbaum, 1913;Pawłowski, 1961;N. Nikitsky, pers. comm.;I. Süda, pers. obs.).Entomologists frequently search this source for insects although only a few O. eremita individuals have been encountered, suggesting that O. eremita visit these habitats only rarely.P. Szwałko (unpublished data) has once observed a female O. eremita feeding on a ripe yellow plum (Prunus sp.).In the laboratory, Schaffrath (2003b) has found that adult beetles feed on bananas and apples.

Habitat requirements
Most findings of O. eremita have been made in hollow but still living, standing trees.The beetle has also been found in dead, standing trees, but probably such trees are often unsuitable because they are too dry.On some occasions (for instance, we know one tree in Sweden, one in Poland, three in Latvia and one in Estonia), living adults or larvae have been found in downed tree trunks.A few times, the species have been found in old stubs (Latvia: D. Telnov, pers.obs.; Russia: N. Nikitsky, pers. obs.;Germany: Stegner, 2002).At many localities, hollows suitable for O. eremita occur only in very large trees, but at other sites the species has also been found at relatively thin, slow-growing trees.For instance, the species has been found in Sweden in a hollow oak (Q.robur), growing on a hill, with a diameter of 22 cm (Ranius & Nilsson, 1997), in central Italy in a beech (Fagus sylvatica) with a diameter of 25 cm (P.Audisio, pers. obs.), and in Germany in a hornbeam (Carpinus betulus) of 25 cm diameter (J.Stegner, pers. obs.).We believe that most oak trees with the beetle present are 150-400 years, while trees of rapid-growing species may often harbour O. eremita when they are younger; poplars (Populus spp.) and willow trees (Salix spp.) may harbour O. eremita when they are only a few decades old (Schaffrath, 2003a).The beetle inhabits fruit trees that are 80-100 years old (Stegner, 2002).Pollarded oaks in France harbour O. eremita when they are only 70-140 years (V.Vignon, pers. obs.).Also in Latvia, the species has been found in many seemingly younger oaks, especially in urban habitats (D.Telnov, pers. obs.).
The species mainly inhabits trunk hollows containing large amounts of wood mould.This has been shown in studies in pasture oaklands in Sweden (Ranius, 2000;Hedin & Mellbrand, 2003).Observations from chestnuts, willows and oaks in Italy confirm this (P.Audisio, pers. obs.).Also Luce (1995) found that hollows of an intermediate to large size were used by O. eremita to a higher extent than smaller hollows.Moreover, the body size of the adult beetles has been found to be larger in trees with more wood mould (Hedin & Smith, 2003).O. eremita inhabits trees with entrance holes situated a few (2-5) metres from the ground more frequently than those with holes near the ground (Hedin & Mellbrand, 2003).However, the beetle occurs over a wide range of heights; it has been found in several tree hollows situated 15-25 m from the ground (V.Vignon, P. Orabi & J.-M.Luce, pers.obs.) but on some occasions also at or even below the ground level (Prunier, 1999;V. Vignon, pers. obs.).
The larvae usually dig between the wood mould and the internal wall of the trunk hollow (Palm, 1959;Pawłowski, 1961;D. Baratelli, pers. comm.).There, they eat the wall and increase the tree hollow and the amount of wood mould.Often the frass from O. eremita larvae is a dominating part of the tree hollow content.In this way O. eremita may improve the habitat for other species living in tree hollows (Ranius, 2002a).Elater ferrugineus L. and other click beetles, Tenebrio spp.and alleculids such as Prionychus spp.are beetle species that often occur together with O. eremita [reported from France (Brustel , 2001), Denmark (Martin, 1993), Germany (Schaffrath, 2003b), Poland (Pawłowski, 1961) and Sweden (Ranius, 2002a)].The most important predator on O. eremita larvae is probably the larvae of the click beetle Elater ferrugineus (Schaffrath, 2003b).Other enemies are less known.Vertebrates predating on O. eremita have only occasionally been reported.However, in Kozienice Forest (central Poland), several adults of O. eremita have been preys of the roller Coracias garrulus L. (Rębiś, 1998).Mites and nematodes are other possible enemies, which so far have only beeen described anecdotally.Larvae infested by mites (deutonymphs of Gamasina), collected in winter (southern Poland) in a hollow stump of alder, died in the laboratory during the following summer killed by these mites (Szwałko, pers. obs.).There is one record of larvae infested by a nematod (Martin, 1993).Protaetia lugubris (Herbst) is a Scarabaeid beetle that seems to have similar habitat requirements as O. eremita (Luce, 1995), and therefore it has been suggested that they may be competitors (Ranius, 2002c).
Most localities today occur on land that has been used by man for a long time.Only in some regions, such as Spain, southern Italy and the Balkans, more or less natural forests are reported to be the major habitat of O. eremita.Perhaps the beetle is to a higher extent associated with man-made, more open habitats in Northern Europe (even though the beetle may occur in shaded situations also in Scandinavia), but occurs in denser forests further south.This could be a compensation for the climate (cf.Thomas, 1993); in regions with colder climate the species tends to avoid the most shaded situations (Ranius & Nilsson, 1997), while in regions with warm and dry climate, free-standing trees perhaps tend to be too dry.However, it is difficult to achieve hard evidence for this hypothesis.
In Scandinavia, pasture woodlands and deer parks with broadleaved trees are the most important habitat.Also in Germany, the largest O. eremita localities are on land that has been used for grazing or hunting (Schaffrath, 2003b).
The species inhabits urban habitats such as parks and alleys.For instance in Banska Bystrica (Franc, 1997), Strasbourg, Rome, Florence, Dresden, Leipzig, Salzburg, and Kaunas, O. eremita occurs in the city centres.In several regions, such as Hungary, Slovakia, some parts of Russia and south-eastern Germany, the O. eremita localities are concentrated to floodplain areas, where the habitat may be forests or smaller woods in agricultural land.Old orchards may be important habitats, especially in central Europe (e.g.Eastern Germany, Austria and Slovenia).
In some regions, the beetle mainly uses pollarded trees.Pollarding implies that tree branches are repeatedly cut in order to increase the productivity of wickers, poles and fuel-wood.In parts of France, there are extensive networks of hedgerows where O. eremita inhabits pollarded oaks.In the intensively cultivated Po river basin of northern Italy, pollarded willows along riversides are the most important habitat for O. eremita.Abandoned practice of pollarding constitutes a threat to O. eremita in these areas.

Metapopulation ecology
In a study in Sweden, the occupancy rate of O. eremita per tree was positively correlated with the number of hollow trees per stand (Ranius, 2000;fig. 2).The positive correlation is consistent with what metapopulation ecologists refer to as Levin's rule (Hanski & Gilpin, 1997).Ecological studies of O. eremita support the view that each tree possibly sustains a local population and that the populations in stands together form a metapopulation (Ranius, 2002b).For instance, the species has been found to have a restricted dispersal (Ranius & Hedin, 2001;Hedin et al., 2003), and the population fluctuations in individual trees take place asynchronously (Ranius, 2001).
A survey of an area in southeastern Sweden revealed that O. eremita still occurs in almost all larger stands, but the occupancy pattern did not indicate any connectivity between stands (Ranius, 2000).This could be because the density of hollow oaks historically has been much higher than today.Over the last two centuries, old oaks have severely declined in Sweden (Eliasson & Nilsson, 2002;Hedin, 2003).Thus, most hollow tree stands were probably colonized by O. eremita long ago and, lately, the beetle has been confined to small stands without connectivity.
In the area surveyed in southeastern Sweden, O. eremita was systematically absent from single trees and very small stands, probably because of extinctions from these stands (Ranius, 2002c).This is consistent with the underlying reasoning of the minimum viable metapopulation size (MVM) concept (Hanski et al., 1996).MVM is an estimate of the minimum number of interacting local populations (in this case hollow trees inhabited by O. eremita) that is necessary for long-term survival of a metapopulation.Computer simulations of O. eremita show that its metapopulation dynamics are slow, in the sense that it may take centuries from the decrease of the number of hollow trees until the small O. eremita population finally become extinct (Ranius & Hedin, 2004).Therefore, in many smaller stands which still harbour a population today, we should not expect O. eremita to be able to survive in the long run (Ranius & Hedin, 2004).

Survey methods
As O. eremita rarely leave the tree hollows, the species must be actively searched for.Where no surveys targeting O. eremita have been conducted, we should expect that many localities with O. eremita remain unknown.
The most efficient methods to survey O. eremita are pitfall trapping (Ranius, 2001;fig. 3) and searching for larvae (Martin, 2002) or remains of adult beetles and excrements in the wood mould (Ranius & Jansson, 2002).Pitfall trapping is carried out during late summer (July-August), when the adults are active.If the traps are emptied at least every second day and the beetles are released, the method is not destructive.By marking, releasing and recapturing the adults, population sizes may be calculated (Ranius, 2001).Martin (2002) has searched for larvae in the wood mould.This is preferably done in late autumn when the larvae occur higher up in the wood mould and are easier to find than at other times of the year.Ranius & Jansson (2002) have searched for remains (pronotum, elytra and heads) of adult beetles and excrements from larvae in a certain amount of wood mould from each tree.In Eastern Germany, excrements have been searched for at trunk-bases and many new occurences were found in this way (Stegner, 2002).Several Scarabaeid species have similar excrements, however, the shape and size make it possible to determine O. eremita excrements (Stegner, 2002).These methods can be used throughout the year and are appropriate when large areas should be systematically surveyed.As excrements and remains of adults may persist for many years, their presence does not ascertain that there is presently a living population in the tree.For this reason it is useful to combine the methods with pitfall trapping: first excrements and remains of beetles are searched for, and then pitfall traps are set only in those trees where excrements or remains of beetles have been found.This is a much more efficient way to search for localities with living adults in comparison to solely using pitfall traps.
Another method to record the presence of the species is to smell for the unmistakable scent of the species.This should be done in July or August, on warm days or afternoons.It is usually necessary to be very near the entrance hole, but sometimes it is possible to smell the beetles from a distance of up to tens of metres.
Window trapping is not an appropriate method to survey O. eremita (Ranius & Jansson, 2002).Hand-collecting of adult beetles is possible, but  because the beetles rarely leave the tree hollows, it is not very efficient.O. eremita does not seem to be attracted by baits such as red wine and molasses, normally used for cetonid beetles.
Known localities with O. eremita may be monitored, either by studying the beetle population itself or by studying its habitat.The beetle population may be monitored by pitfall trapping.The field work must be done at the correct period (which differs between years), pitfall traps must be set in a sufficiently number of trees, and the data must be statistically analysed (Ranius, ).The habitat may be monitored by revisiting the localities, checking that the inhabited trees are alive and not suffering from competition of neighbouring trees or any other threat.This is much cheaper than monitoring the beetle population, and may generate advice about which management measures are needed.The potential to get new hollow trees in the future should also be evaluated and planned for.Both these kinds of monitoring may be conducted, for instance, every five years.

Occurrence in individual countries
The occurrence of O. eremita in each country where it occurs (fig.4) is described below.Lists with localities (those mapped in the figures) are given in the Appendix.Updated information about projects dealing with O. eremita are available at the web site www.eremit.net.

Albania (fig. 5)
Most records are from the northern part of Albania.The only information obtained regarding host tree concerns an adult found in Tamara on a beech (Fagus sylvatica) (W.Schwienbacher, pers.com.).The species has been found both in lowland (Shkodër) and mountain areas (Maja e Ragamit, Maja e Poliçanit).

Austria (fig. 6)
O. eremita is regarded as a highly endangered species (Franz & Zelenka, 1994).However, it has been recorded from more than one hundred localities dispersed over a wide part of Austria.The distribution has its centre on the thermically advantaged Eastern Lowland and extends to the inner-alpine Low Mountain Range, 800-1,000 m a.s.l.Previously, the species was found in wood and parkland landscapes managed with a low intensity, but today the species is restricted to old fruit plantations, trees along paths and streams, and at estates and animal parks with protected woodland.Some of the localities are large and only managed with a low intensity by humans.The inhabiting O. eremita populations therefore probably have a low extinction risk here.Such localities are the parks of Laxenburg (B.Dries & J. Roppel, pers.comm.) and Purgstall (F.Ressl, pers.comm.) in Lower Austria, the Lainzer Tiergarten in Vienna (Zabransky, 1998), and the old fruit plantations in the smallholdings in Upper Austria and in the western parts of Styria (Kreissl, 1974;Mitter, 2001).Oak (Quercus spp.), willow (Salix spp.) and lime trees (Tilia spp.) are the most important tree species, whereas beech (Fagus sylvatica), ash (Fraxinus excelsior), elm (Ulmus glabra) and birch (Betula spp.) are more rarely used.Apple (Malus spp.) and pear (Pyrus spp.) orchards seem to be important habitats in some areas.Occasionally O. eremita has been reported from introduced tree species such as horse chestnut (Aesculus hippocastanum), black poplar (Populus nigra var.pyramidalis) and false acacia (Robinia pseudoacacia).
Our present knowledge on the distribution of O. eremita is mainly due to coincidential collecting.Reports for many localities are old and the species may have become extinct due to habitat loss.
During the last few years, several new localities with O. eremita have been discovered.One locality is the park of Priluki in the Minsk district.This is an ancient park with old lime, ash and oak trees.There are many similar parks in Belarus where O. eremita would possibly be found if the species was surveyed.

Belgium (fig. 8)
The last confirmed record of O. eremita in Belgium dates back to 1944, and the species has therefore been regarded as regionally extinct.However, a recent record has been reported from the valley of "la Berwinne" (near Visé).O. eremita has been recorded from 15 localities in three different provinces: Brabant (central Belgium), Limburg (eastern Belgium) and Luik (southeastern Belgium).It has been found in old trees in woodlands (mainly oak (Quercus robur)), river-sides, pastures (mainly willows (Salix spp.)), and orchards (apple (Malus domestica), cherry, prune (Prunus spp.) and pear trees (Pyrus spp.) (Janssens, 1960).O. eremita in Belgium is classified as endangered and is protected.
Belgium has a long history of forest fragmentation and remaining forests have been intensively managed, with a huge impact on fauna and flora (described by Desender et al., 1999).Especially in the northern part of Belgium (Flanders), forests have totally disappeared (e.g.Tack & Hermy, 1998), while in Wallonia, natural forests have been converted to intensively managed tree plantations.Old trees have been removed, and are still being removed, not only from forests but also from agricultural areas.As a result, the chance for beetles dependent on tree hollows to persist has severely decreased.
No survey specifically targeting O. eremita or any other saproxylic insects has been conducted during the last few decades other than two recent surveys of saproxylic beetles in a few forests (Versteirt et al., 2000;Heirbaut et al., 2002).Old localities where the species has been found have not been revisited for the study of O. eremita.

Bosnia and Herzegovina (fig. 9)
There are old records of O. eremita from a wide range of Bosnia-Herzegovina.The altitudinal range is from 50 (Mostar) to 1,350 m a.s.l.(Igman and Treskavica).
Localities with the species present are almost certainly still widespread throughout the country.However, owing to the civil war, it seems no surveys have been conducted over the last few years.

Bulgaria (fig. 5)
In Bulgaria, O. eremita has been recorded from the large mountain area of Stara Planina (which extends in the centre of the country from W to E), from the southwestern mountains (Rila and Pirin Mts.) and from the Black Sea coast.Nüssler (1986) has reported the species from locality 1,400 m a.s.l.We know the habitat only for two single specimens: one has been flying in an orchard (M.Mazur, pers.comm.) and another collected in "xerothermic scrub" (E.Migliaccio, pers.comm.).

Croatia (fig. 9)
In Croatia, O. eremita has a broad range, but is rare.There are records from 31 localities, made between 1892 and 2000.O. eremita is not a protected species but some localities with O. eremita are protected areas (such as Mt.Velebit, Mt.Učka, Mt.Papuk, Mt.Medvednica, Žumberak and Plitvice).No surveys focusing on O. eremita have ever been conducted in Croatia.

Czechia (fig. 6)
O. eremita is local and rare in the Czech republic; in the Red Data Book of the Czech and Slovak Republics it is regarded as endangered (Škapec, 1992).Most of the O. eremita localities are situated in southern and eastern Bohemia and mostsouthern and north-eastern Moravia, but there are a few localities also in other parts of Czechia.
Numerous suitable habitats have been lost during the last fifty years.Nevertheless, some habitats, for instance, parks near castles and alleys, have been preserved as isolated fragments with local O. eremita populations still present.Some O. eremita populations inhabit preserved lowland   forests with large broadleaved trees, especially in southern Moravia.Many populations seem to be small and isolated, so the risk of local extinctions in many cases is probably high.Another endangering factor in Czechia is the ongoing removal of "unhealthy" hollow trees, especially in anthropogenic habitats which host the majority of the O. eremita populations.
The distribution of O. eremita is relatively well known, with over 500 findings from about 200 localities.This is due to a high number of entomologists in the Czech Republic; the species has never been systematically surveyed.
The first published survey of distribution of O. eremita in Czechia was a grid map by Jelínek (1992).More recently, Kollar (2000) summarized O. eremita records.During the last two years, mapping has been conducted within the scope of NATURA 2000.A more detailed survey is in preparation by K. Chobot.

Denmark (fig. 10)
O. eremita is rare in Denmark, and has only been found on Eastern Jutland (Jylland) and the islands Zealand (Sjaelland), Lolland, and Falster (Martin, 2000).It seems to have become rarer in Zealand over the last 100 years, and has probably disappeared from Jutland, whereas its presence in several localities on Lolland have been discovered during the last few decades.There are records from 28 localities.However, when these were recently revisited, the species were only found in 9 of them, even though hollow trees are still present at all localities.O. eremita was searched for in every tree whenever possible.However, some entrance holes were too small or situated too high to reach by ladder.At the largest locality (Bognaes Storskov, Zealand) O. eremita was found in 16 trees, while at the other localities the species was found in 2-10 trees.This means that the survival of the O. eremita in Denmark is uncertain in the very near future as the populations are small and very isolated.
The species has been found breeding in several different deciduous trees, and once also in a conifer tree: silver fir (Abies alba).The most important habitat is privately-owned deer parks or forests situated near old estates and manors.There, the species occurs mainly in oak (Quercus robur) beech (Fagus sylvatica), and ash (Fraxinus excelsior).Outside the forests, it has especially been found in avenue trees: lime (Tilia cordata), elm (Ulmus glabra) and horse chestnut (Aesculus hippocastanum).
Specimens from 28 localities were registered, when museums and private collection were re-viewed in 1990-1991.These 28 localities were surveyed, and living specimens were found at 10 localities (Martin, 1993).When these ten localities were inventoried in 1999 (Martin, 2002), O. eremita was found in 61 hollow trees (46 oaks (Quercus robur), 10 beeches (F.sylvatica), 3 horse chestnuts (A.hippocastanum) and 2 ashes (F.excelsior)).Of these trees, 49 were alive, although several later fell during a hurricane in December 1999.Estonia (fig. 11) Until recent years, O. eremita was known in Estonia only from an undated record from Tartu, probably originating from the 19 th century.In 1995, the species was found in an oak in a wooded meadow in Koiva woodland in southern Estonia.The beetles have since been found there repeatedly, once feeding on a flow of oak sap.A cocoon including remains of an adult has also been found in a hollow maple (Acer platanoides) stub in an avenue at Koikküla, a village situated nearby (Süda, 1998(Süda, , 2003)).
Starting in 1999, the Estonian Seminatural Community Conservation Association performed socalled bush clearing in the woodland.The aesthetic aspect was over-emphasized in the work and a large amount of dead or broken trees were burnt or removed, including large oak trees (Süda, 2003).Despite this, O. eremita is still present at woodlands along the Koiva river, although the number of suitable trees is small.
The existing population and possible new populations were searched for in 2000-2002 within the Estonian NATURA 2000 program.Despite the extensive search, no new records of O. eremita were recorded, although suitable habitats can be found at other places in Estonia, e.g. on Saaremaa Island.

Finland (fig. 11)
O. eremita is only known from one locality in Finland: the island of Ruissalo (Runsala) in Turku.This is however a large locality; in an area of about 5 x 2 km, living specimens have been found in 117 trees, remains from adults occurred in 62 trees, and excrements were found in another 155 trees (Landvik, 2000).

France (fig. 8)
In France, more than 300 localities with O. eremita are known.Thus, O. eremita is widely distributed in France, but most existing sites are relatively remote from each other, leaving wide empty spaces, particularly in forest regions.The species seems to have decreased severely, especially in the northern part of the country.In the southern part of France, there are probably still many localities that have not been discovered (J.-M.Luce, pers. comm.)(Garrigue & Magdalou, 2000) and the Forest of Sare (Pyrénées Atlantiques) (Van Meer, 1999); and (6) religious sites, such as the beech grove on the pilgrim site of the Sainte-Baume (Var Department) in the Provence region.
In contrast with these isolated forest habitats, there are often many more hollow trees in hedge-row networks where O. eremita exists.There, the species mainly inhabit old, pollarded oaks.Examples of such networks are, for instance: (1) in the north of the Aveyron Department in an area of more than 500 km²; (2) in Bourbonnais in the Allier and Cher Departments in an area about 2,000 km²; and (3) in the west part of France in an area about 30,000 km², in the Ille-and-Vilaine, Indre-and-Loire, Loire-Atlantique, Maine-and-Loire, Morbihan, Mayenne, Orme and Sarthe Departments (Vignon & Orabi, 2003a, 2003b).
Before land consolidation (in the sixties), O. eremita occurred probably continuously in landscapes with hedgerow networks.Today, the hedgerow networks have become more fragmented.
A pollarded oak grows relatively fast; a tree with a diameter of 50 cm is normally between 70 to 120 years old (Brin, 1999), and such a tree may harbour O. eremita.Pollarded trees over 300 years old are very rare, and trees over 140 years seem to die relatively fast.Very old, dying trees are normally cut down to be used as firewood, partly for aesthetic reasons.
Only a few sites have been subject to detailed surveys of hollow trees and O. eremita.When trees were mapped in the forest of Massanne, there were on average 60 hollow trees per hectare.The occupancy rate of O. eremita was about 6% (Garrigue & Magdalou, 2000).Two hedgerow network regions in the western part of France, that may form the largest locality for O. eremita in France, have also been surveyed.In an 8,500 hectares site in the Sarthe Department, one hollow tree per hectare was found.Even in this fragmented site, O. eremita was present.In the Orne Department, a hedgerow network was found to have 5 hollow trees per hectare in an area of 5,000 hectares.The highest density observed in hedgerow networks is 10 hollow trees per hectare in 200 hectares which have never been subjected to land consolidation (J.-F.Asmodé & V. Vignon, pers. obs.).O. eremita occurs in 2 to 20 % of the hollow trees in different parts of the hedgerow network in the Sarthe and Orne Departments (J.-F.Asmodé & V. Vignon, pers.obs.).A higher occupancy rate, 26%, has been observed in a hedgerow network in the Aveyron Department (Brustel, pers. comm.).
The low occupancy rate in the hedgerow networks implies that there is a long distance between trees harbouring O. eremita.Therefore, the habitat fragmentation is at many places probably too high for long-term survival of the species.We assume that in more than 80% of the localities where O. eremita is present today, there is a substantial risk of extinction within 50 to 100 years.A study of a Carabid beetle in a hedgerow network indicated that its current distribution was better correlated with characteristics of the landscape 50 years ago than the present situation (Petit & Burel, 1998).Perhaps the situation is similar in O. eremita, and in which case we should expect local extinctions in the future due to the habitat destruction over the last few decades.
At many sites, there are no younger trees to take over the role as hollow trees in the future.As it will take a long time before new hollow trees are generated, survival of insects in hollow trees is possible only as long as the present old trees are preserved.
The hedgerow networks, which constitute the most important habitat for O. eremita, have been subject to severe fragmentation since the 1960's.The decrease in numbers of hollow trees is not only due to the reduction of hedgerows, but also to the lower density of trees in the hedgerows.Today, the hollow trees are very old, and renewal of the habitat is difficult.The traditional practice of pollarding trees has been abandoned because it no longer serves any economic function.This development is also a consequence of the agricultural policy favouring intensive farming of cereals, for example, rather than cattle rearing and horse-breeding.
Forests with high densities of hollow trees are small and rare.It takes longer for hollows to form in forest trees than in pollarded trees.Therefore, the renewal of hollow trees in forests is in many cases difficult.Planning for the maintenance and the renewal of hollow trees has to be conducted in cooperation with administrators of the countryside and foresters.

Germany (fig. 6)
More than 1,000 records of O. eremita (both recent and historical) are known from Germany.They are mainly from lower regions (less than 400 m a.s.l.) (Schaffrath, 2003b).O. eremita occurs in all federal states in Germany.According to Schaffrath (2003b), there are at present 111 localities with O. eremita.However, investigations in recent years have resulted in a growing additional number (see Stegner, 2002;Ringel et al., 2003).The highest density of localities are in parts of Baden-Württemberg and Hessen and Niedersachsen and in Eastern Germany (Mecklenburg-Vorpommern, Brandenburg, Sachsen-Anhalt, Sachsen).In Mecklenburg, Brandenburg, Berlin and Baden-Württemberg, the localities are often wide, open forests.In Sachsen and Sachsen-Anhalt, O. eremita is widespread, especially in great flood plain areas around Elbe, Mulde and Saale which contain remnants of old forests and pasture lands.O. eremita also occurs in landscape parks, orchards (especially known in Sachsen) or historical pond regions, where oaks have been planted around the ponds (Stegner, 2002).On the outskirts of villages there are often pollarded trees, especially willows, that may be used by the beetle.In cities, sometimes even in the city centres, O. eremita regularly live in alleys, city parks and cemeteries.The most important trees are oak (Quercus spp.) and lime-trees (Tilia spp.), followed by willows (Salix spp.), beech (Fagus sylvatica) fruit trees (Malus spp., Prunus spp.) and ash (Fraxinus excelsior).
Changes in land use, both in agriculture land and in forests which affect O. eremita, took place in Western Germany several decades earlier than in the East (Schaffrath, 2003b).Old-growth forests have been cut down, and forests with lime trees, oaks, hornbeams and beeches have been replaced by conifer plantations.Where deciduous forests remain, trees are usually cut down long before tree hollows can be generated.In pasture landscapes and parks, free-standing trees have become scarcer for several reasons, for instance due to ceased removal of underwood (Vera, 2000).On agricultural fields and in alleys trees have been removed.Besides, a wide relinquishing of old fruit plantations has led to a massive lost of suitable habitats in Western Germany (Stegner, 2002).A problem, which today is mainly "eastern", is the loss of large trees due to the development of housing and trade areas and new highways (Saxony: Lorenz, 2001;Schaffrath, 2003b).For instance, many trees with O. eremita were lost due to the building of an automobile factory in Dresden.
In Germany, the conservation of O. eremita should be ensured by the Federal Nature Protection Act, but due to the safety regulations based on civil law, liability laws and insurance laws, hollow trees in cities and villages are often cut much earlier than necessary.Possible safeguards for trees are rarely considered.Many localities with O. eremita are included in NATURA 2000 sites (according to EU's Habitats Directive), but especially trees in towns are usually not included in such sites.This means that some important localities for O. eremita in Germany do not have any site protection by NATURA 2000 (Schaffrath, 2003b;Stegner, 2002).
Many findings in Germany occur in isolated trees or very small stands where it is unlikely the species will be able to survive in the long term.In the 19 th century, O. eremita was probably common all over Germany (Horion, 1958).In the 1950s, Horion (1958) described the beetle as "...only local and not common; in the west and southwest a rarity...".Schaffrath (2003b) published the first grid-based distribution map for Germany, based on historical and recent records available from museums and private collections.A coordinate-based map of Sachsen (Saxony) was published by Stegner (2002) and is continued under www.eremit.net.A grid-based map of Mecklenburg-Vorpommern was published by Ringel et al. (2003). .Last record 1950-1989; .Last record in 1990 or later. .Último registro de 1990 o posterior.According to a new focus of nature protection on O. eremita, numerous investigations have recently been accomplished, collecting a lot of new data.The preparation of management plans for NATURA 2000 sites in the next few years as well as the demand for monitoring by Habitats Directive will give us even better knowledge about the occurrence of this species.

Great Britain
O. eremita does not occur in Great Britain (Alexander, 2002).

Greece (fig. 5)
O. eremita seems to be widespread in Greece, but not common.It has been found from the low hills of the Peloponnese (Elis) to 1,700 m a.s.l.(Katara Pass).Most findings have been made in mountain forests of beech (Fagus sylvatica), chestnut (Castanea sativa), and Grecian fir (Abies cephalonica) (G.Gobbi, A. Liberto & D. Baiocchi, pers comm.).In Thessaly, the species occurs in beech, oak, and willows in the deciduous forests of Mount Ossa and Mount Olympus, between 100 and 1,200 m a.s.l.(Dutru in Tauzin, 1994b).Hungary (fig.6) Endrödi (1956) stated that O. eremita was rare in Hungary, but distributed throughout the whole country.This was confirmed when we went through insect collections.Most findings are from floodplain areas, mostly in willow trees (Salix spp.).However, the species also occurs at other places, for instance on Kékes, the highest mountain peak in Hungary.
O. eremita is on the National Biodiversity Monitoring Program (Merkl & Kovács, 1997) as a relevant species when monitoring very old trees or forests.However, so far no detailed studies have been conducted on the species in Hungary.
Along the Aterno river valley (Pile and Preturo) and the Peligna river valley (Sulmona), as well as at the springs of Pescara river (Popoli), O. eremita occurs mainly in woods of white willow Salix alba (Marotta et al., 1997).Also in Pianura Padana (Po Valley), a large and intensively cultivated lowland, O. eremita is mainly found in planted willows.Further south, the distribution of O. eremita ranges from the remnants of evergreen Mediterranean forests, which stretch along the Tyrrhenian coast up to the belt of montane beech forest.Several O. eremita localities are in the submontane and low montane belt of central and southern Apennines, while others are in beech forests of Abruzzo, Basilicata and Calabria.Along the central Tyrrhenian coast, the species has only been found in two adjacent natural reserves: Castelfusano and Castelporziano, both situated 20-30 km from Rome.Despite intensive search, O. eremita has never been found in the Circeo National Park, which includes large areas of forests with old trees.
During the last few decades, several records of O. eremita have been made in old trees (mainly oaks) situated in parks or avenues in urban areas (e.g.Florence and Rome).An example of such a locality is "Villa Borghese", a historical park situated in the centre of Rome, where the beetles live in old holm oaks (Quercus ilex).At such places the old hollow trees are threatened due to conflicts with public safety.
We have more information about the species from northern Italy, due to the large number of entomologists there.Surveys focused on O. eremita have been carried out only recently and are still in progress (P.Audisio and G. Carpaneto in Central Italy and A. Ballerio and D. Baratelli in northern Italy).

Latvia (fig. 11)
O. eremita is known throughout Latvia, but most of the populations are small and isolated.Today more than 302 findings are known from 83 localities.95% of the localities have been discovered during the last four years.This species is protected in Latvia and included in the Red Data Book of Latvia (Spuris, 1998).
The species mainly inhabits old parks, avenues, old broad-leafed forests, and pasture woodlands (Spuris, 1998;Šternbergs, 1988;Telnov, 2001Telnov, , 2002;;Telnov & Kalninš, 2003).Sixty percent of all records are from agricultural and urban areas, mainly city parks and alleys.In forests, the species has only been observed in very old trees, while in agricultural and urban landscapes O. eremita often inhabits trees that seem to be comparatively younger.Lime tree (Tilia cordata), oak (Quercus robur) and maple (Acer platanoides) are the most important tree species (Telnov, 2001(Telnov, , 2002)).In forests, the localities are usually small (often 1-3 trees) and situated several kilometres from each other.Some old parks and avenues harbour tens of suitable trees.
The species is monitored since 2000 by revisiting localities and observing species presence/absence.The only extinctions observed so far have been the result of felling old trees regarded as dangerous in the city of Riga and other places.Because many populations are so small and isolated, the risk for local extinctions is high during the following few decades.
Data from literature and insect collections (museums and private) have been compiled.In the collections there were only about 55 specimens collected during the last 155 years.Field surveys have been conducted mostly during the last four years.

Lithuania (fig. 11)
In Lithuania, O. eremita is rare and regarded as vulnerable (Pileckis & Monsevičius, 1992) with most findings being from the central part of the country (Pileckis & Monsevičius, 1995).The species has been found in oak (Quercus spp.), maple (Acer platanoides) and ash (Fraxinus excelsior), both in parks and forests.There are only two localities, both near Kaunas, where O. eremita has been recorded several times: Kaunas Oakery (Azuolynas) Park (in the city center of Kaunas), where there are many oak and lime trees, and a mixed forest near Kaunas.No survey focused on O. eremita has ever been conducted in Lithuania.

Macedonia (fig. 5)
In the literature, we found one record of O. eremita from in Macedonia (Mikšić, 1955); it was from 1941.
The Netherlands (fig.8) O. eremita is considered extinct in the Netherlands.The last specimen was collected in 1946 in Wijnandsrade, in the extreme south of the country.The very few specimens in Dutch collections suggest that O. eremita has been extremely rare over the last 200 years.Most of the Netherlands has been deforested for centuries and localities with a long-term supply of decaying large trees have been particularly scarce since a long time ago.As a result, many saproxylic insects occurred in isolated populations and eventually became extinct.
No specific surveys focused on O. eremita have been conducted.Many skilled amateur coleopterists have been active there during the last century and it seems most unlikely that they have overlooked O. eremita during this time.

Norway (fig. 10)
Live specimens of O. eremita have not been found in Norway during the last 100 years.During the 19 th century, the species was noted from Drammen (Siebke, 1875) and Asker (Strand, 1960;Kvamme & Hågvar, 1985).There are no specimens from Drammen or Asker in the zoological museums of Norway today, but an adult specimen in the collection of Zoological Museum in Oslo is labelled "Ex.Coll.Norway.Einar Fischer" (Karsten Sund, pers. comm.).During the last few decades only fragments of adult specimens, probably of very old origin, have been found.They have all been collected in hollow oaks at a third locality, on Rauer Island near Fredrikstad (Strand, 1960;Zachariassen, 1981;Hanssen & Hansen, 1998).
Several collectors have searched for the species during the last twenty years, but the negative result has led to the assumption that the species has probably disappeared from Norway (Zachariassen, 1981(Zachariassen, , 1990;;Hanssen et al., 1985).On the Norwegian Red List (Anonymous, 1999) the species has been given the category "Extinct?".O. eremita was one of ten invertebrate species proposed for protection nation-wide according to the Nature Conservation Act (Anonymous, 1994).However, finally O. eremita was not protected according to this act, because it was assumed to be regionally extinct (Øystein Størkersen, Directorate for Nature Management, pers. comm.).
Suitable habitats for O. eremita, such as hollow trees of oak (Quercus robur), beech (Fagus sylvatica) and lime (Tilia cordata), occur mainly in the agriculture landscape in the county of Østfold and Vestfold.In addition, there are a few areas with stands of old oaks in woodland, especially in the hilly landscape around Lake Farrisvannet in Vestfold.The areas around Drammen and Asker are today, like all urban areas around the Oslofjord, heavily exploited and very few localities with hollow trees are left.
During the last decades, it is mainly huge oaks with great openings near the ground that have been investigated (Zachariassen, 1981;Hanssen et al., 1985;Hanssen & Hansen, 1998;Hanssen, 1999).Trees with entrance holes that are small or higher up are less studied in Norway and may possible contain undiscovered populations of O. eremita.

Poland (fig. 6)
The distribution area covers the whole of Poland, except for mountainous areas.The highest altitude where the species has been found is 885 m (Zakopane; Oleksa et al., 2003).In the east, where the species' occurrence is better known, it occurs in old trees in small groups along river banks, field roads, property borders, and sometimes in old orchards and parks.It has also been found relatively often in urban habitats such as old avenues, city parks and cementeries.In broadleaved and mixed forest, O. eremita is rare but probably still present in older stands and wood margins, especially at sites difficult to reach.When saproxylic beetles were inventoried in thirteen nature reserves of Upper Silesia (former Katowice Province), O. eremita was found in three reserves (Szafraniec & Szołtys, 1997;J. Michalcewicz, pers. comm.).In 10 x 10 km squares in the Niepołomice Forest (southern Poland), O. eremita was present in at least three out of six squares (P.Szwałko, pers. obs.).In northern Poland, an inventory from 1999-2003 between Elbląg, Iława, Susz, and the river Pasłęka (northern Poland), revealed that O. eremita occurred in 24 out of 37 investigated 10 x 10 km squares (A.Oleksa & R. Gawroński, unpubl. data).
Oak (Quercus robur) is the most important host tree for O. eremita in Poland.Willows (Salix spp.) and lime trees (Tilia spp.) are often used and, rarely, fruit trees or common alders (Alnus glutinosa) are used, while there are only single reports from beech (Fagus sylvatica), ash (Fraxinus excelsior) and horse chestnut (Aesculus hippocastanum) (Pawłowski, 1961).In the Niepołomice forest, cocoons containing remains of larvae and adults of O. eremita have been found in Scots pine (Pinus sylvestris) (Oleksa et al., 2003).
In the second half of 19 th century, O. eremita was probably still abundant and frequent in Poland.Contemporary authors (e.g.Letzner, 1871) reported it as being found relatively often.For that reason they did not list localities for O. eremita, in contrast with other beetle species that are more common today.O. eremita has lost most of its habitats today and is extinct in some areas (Szwałko, 1992b).The species is included in local and national red lists (Szwałko, 1992b;Pawłowski et al., 2002).Old trees have been removed in managed forests, along roads and in urban areas, regarded as a source of "pests and pathogenic fungi" or a danger for humans and vehicles.Many monumental trees, which are specially protected by law, have been "cured" by mechanical cleaning of the hollows and impregnating of the wood surface with pesticides (Szwałko, 1992a).Such methods of "conservation" have been restricted due to Polish implementation of the Bern Convention and EU's Habitat Directive.New forest management methods promote preservation of some old, especially hollow, trees wherever possible.Localities where the species still exists have already been or will be protected under the recently started NATURA 2000.On the other hand, in many managed forests (including some forest nature reserves) the wrongly understood "aesthetic mind" gives rise to further elimination of O. eremita habitats (Gutowski & Buchholz, 2000).As a result, other habitats, such as woods along fields, streams and lakes become more important for the survival of the species.
About 170 localities in Poland are known.Much of the information has originated from entomologists working mainly in the eastern part of Poland, which at least partly explains the lower density of findings from north-western Poland.To get a better picture of the whole situation in Poland, investigations in the western part of the country are desirable.

Rumania (fig. 5)
In Rumania, 27 localities with O. eremita are known.At ten of these, records have not been made since 1911 (Fleck, 1904(Fleck, -1906;;Petri, 1912), which can be explained by the low search effort.   .Last record in 1990 or later.O. eremita occurs, for instance, in oak or mixed forests along the Danube alluvial plain and in beech or hornbeam mixed forests at the foot of the Carpathians.In many forests, trees with hollows are often removed because they are considered a potential danger.

Russia (fig. 7)
In western Russia, O. eremita has been found in the zone of nemoral and boreo-nemoral forest, in 18 different regions and in 6 republics.The species occurs mainly in hollow oak trees (Quercus robur), and less frequently in willow (Salix spp.), aspen and poplar (Populus spp.), lime (Tilia cordata), ash (Fraxinus excelsior), apple (Malus spp.), pear (Pyrus communis) and elm (Ulmus laevis) trees.Larvae have occasionally been found to develop in stubs.
For most parts of Russia we have only limited knowledge about the species' occurrence, but more is known regarding a few regions, such as Chuvashiya.At least 70 specimens were observed in Chuvashiya between 1988 and 2002.The species occurs mainly in oak woods along the Volga banks, from the western to the eastern border of the republic, in floodland oak woods along the Sura and in oak woods in the central and eastcentral parts of Chuvashiya.The height ranges from 70-200 m a.s.l.O. eremita has almost never been found in those wide areas in southern and south-western Chuvashiya that are covered with mixed forests, and it has not been found in the steppes in the south-west and south-east.In floodland oak woods near the Sura River in the protected zone of the Prisursky State Nature Reserve, Alatyr district, it is relatively easy to observe the beetle in hollow trees, which occur abundantly there.
O. eremita is decreasing in Russia because old broad-leaved trees are cut down.Some local populations (e.g., in some parts of Cuvashiya and Udmurtiya) are more or less safe because they are in reserves or other areas where the trees are not being felled.In all unprotected areas, the species is vulnerable due to mass cutting of old oaks.The species has been included in the Red Data Book of the Russian Federation (Nikitsky, 1983(Nikitsky, , 2001)), USSR (Lopatin, 1984) and in some regional Red Data Books, e.g. of Bashkirsky ASSR (Boev et al., 1987), Tatarstan Republic (Muravickij & Kanitov, 1995), Moscow region (Kompantsev, 1998), Adygeya republic (Cherpakov & Bibin, 2000), Kirov region (Yuferev, 2001), Ryazan region (Ananyeva & Blinushov, 2001), Udmurtiya republic (Borisovsky, 2001), Leningrad region (Krivokhatsky, 2002), Mari El republic (Baldaev, 2002), and Stavropol region (Sigida, 2002).To preserve O. eremita and other species associated with ancient trees, regional branches of the Ministry of Natural Resources of Russia should restrict the permits to cut down old trees, especially oaks.Data from specimens in museums and private collections have been collected.In most of these localities, we know that O. eremita is still present.
Serbia and Montenegro (fig.5) O. eremita is known from twelve localities in Serbia and five in Montenegro, at an altitude of 70-1,140 m a.s.l.Ecological data are scarce, but we know that in the protected area of Kapaonik, at Šanac, an adult beetle was collected on an oak (Janković, 1972).

Slovakia (fig. 6)
As early as 50-70 years ago, O. eremita was reported to be declining in the present territory of the Czech and Slovak Republics (Fleischer, 1927(Fleischer, -1930;;Pfeffer et al., 1954).However, the beetle occurred at many sites in southern and central Slovakia and was locally not rare (Roubal, 1936).Since that time, nature in Slovakia has been modified by human activity, and changes in the landscape have mainly occurred in easily accessible lowlands and foothills.Numerous valuable habitats such as pasture woodlands, old trees growing in small groups, alleys and hedges as well as trees bordering rivers and streams have been lost.Nevertheless, this was not excessive compared to the rest of Europe (Zach, 2003); some habitats have been retained in the form of isolated fragments and local O. eremita populations have survived.
A distribution map of O. eremita was compiled by Jelínek (1992) using data from J. Roubal and L. Korbel and archive material from the Faunistic Section of the Czecho-Slovak Entomological Society.According to this map, there were 20 localities up to 1960.Most of them (16) were located in western, southern and central Slovakia.In the period 1960-1990, seven sites in southern and western Slovakia were recorded on a map, while there were no localities in central and eastern Slovakia.This might indicate a strong decrease in the number of O. eremita localities in Slovakia.However, when we compiled information about the present range of O. eremita, the beetle was recorded from more than 30 localities.Obviously, some of them were not included in the study by Jelínek (1992).The explanation for this can simply be that more information has been obtained since that time, although no one is currenty studying the beetle in detail.
O. eremita occurs mainly in the following habitats: (1) oak pasture woodlands with scattered groups of trees or solitary trees; (2) floodplain forests with large trees.It mainly breeds in large willows, poplars and oaks -the latter in drier situations; (3) parks and alleys; (4) abandoned orchards, today a very scarce habitat; (5) mixed oak and pine forests; and (6) forest edges with large trees growing on south-facing slopes.
The advantage of polyphagy for Slovakian forest beetles in general (Whitehead, 2000) is, in the case of O. eremita, eroded by the ongoing removal of dying and dead trees.Large dead trees are not often being replaced by younger ones.This will cause local extinctions of O. eremita populations.In town parks, tree hollows in "unhealthy" trees are cleaned, and this may destroy populations.In the Slovakian Red-List, the species is categorized as "endangered" (Holecová & Franc, 2001).
Further data may be available from museums and private collections.Co-operation with researchers involved in bat studies carried out in tree hollows may reveal new O. eremita localities.

Slovenia (fig. 9)
O. eremita was first described by Scopoli (1763) when he was a physician in Idrija (Eastern Slovenia).Since that time it has been mentioned in faunas of different regions of Slovenia as infrequent (Scopoli, 1763;Siegel, 1866;Brancsik, 1871;Martinek, 1875).It seems that the species is distributed all over Slovenia where suitable habitats are present.Old willows (Salix spp.) are reported as the most common finding place, but also oak (Quercus spp.) and fruit trees are mentioned as habitat for the species (Scopoli, 1763;Siegel, 1866;Brancsik, 1871;Martinek, 1875).In the collections there are many very old specimens, but recent records are few, suggesting that the species has decreased.The reason is probably the same as in the rest of Europe -old fruit orchards as well as other old trees have become much rarer.The species is considered endangered by the Slovenian Red List (Anonymous, 2002).O. eremita has never been surveyed systematically in Slovenia.

Spain (fig. 8)
O. eremita seems to be very rare in Spain.It has been found along a narrow band in the northern part of the country running from the Picos de Europa in the west to Montseny (Barcelona) in the east.Apparently suitable habitats are found further west from its known Spanish distribution area but the species has not been reported there.
The main habitat for O. eremita in Spain is humid deciduous forest.Most records come from beech (Fagus sylvatica) forest in the mountains of the Pyrenees or Picos de Europa.In Navarra it has been found in old forests of oak (Quercus robur and Q. humilis).
In most cases, adults have been found walking on old beech or oak trunks, in shaded and humid parts of the forest (Montada Brunet, 1946, San Martín et al., 2001;C. González, pers. comm.;G. Aguado & L. O. Aguado, pers. obs.).In a single case, an adult was found on an inflorescence of Sambucus nigra (Bahillo de la Puebla et al., 2002).The species seems to be absent from more anthropogenic environments such as bocages and urban parks.Adults have been observed mainly in the daytime but some captures have been obtained at night, using artificial light (San Martín et al., 2001).
In 1995-96, the information about all Spanish arthropods listed in the Habitat Directive of EU was gathered and distribution maps and available  .Último registro en 1990 o posterior.biological information on O. eremita were published (Galante & Verdú, 2000).However, no comprehensive revision of entomological collections seems to have been carried out.Since then, new records have been published that extend the Spanish distribution area to the West (Bahillo de la Puebla et al., 2002;Ugarte San Vicente & Ugarte Arrue, 2002) and South (San Martín et al., 2001).These new records suggest that the species has been overlooked in the past, due to inefficient sampling methods or low sampling effort.

Sweden (fig. 10)
The highest concentration of known O. eremita localities in the world occurs in south-eastern Sweden.O. eremita occurs only in the southern part of Sweden, up to the northern limit for oak pastures.The main habitat is pasture woodlands with old oaks, especially near castles, estates and churches (Ranius, 2000).There are also some records from parks, avenues and deciduous forests (Antonsson et al., 2003).Oak (Quercus robur) is by far the most important tree species.Especially in the very south of Sweden, O. eremita has also been found in several other tree species, such as beech (Fagus sylvatica), ash (Fraxinus excelsior), lime (Tilia chordata), common alder (Alnus glutinosa) and horse chestnut (Aesculus hippocastanum) (Antonsson et al., 2003).
Old oaks were very common in the Swedish agricultural landscape until 200 years ago, but for a few decades in the early 19 th century, farmers removed hundreds of thousands of old oaks from their land (Eliasson & Nilsson, 2002).It was mainly on land owned by the nobility where oaks were left.Today, ceased grazing is a severe threat to the oaks on pasture woodlands, mainly because the old trees suffer from competition and shading from the younger ones.Forest regrowth also changes the microclimate in the trees and many saproxylic beetles suffer from this (Ranius & Jansson, 2000).About 30% of the localities are protected as nature reserves, and it is mainly the largest localities that are protected (Antonsson et al., 2003).The majority of localities are small, with only a few suitable trees situated more than one kilometre from other localities.At these sites the risk for local extinctions during the following decades is substantial.There are, however, a few localities with more than 100 suitable trees (e.g.Bjärka-Säby, Sturefors and Hallands Väderö).At these sites, measures are taken to preserve the hollow tree habitat.Therefore the extinction risk for O. eremita at a national level is probably low.However, there is still no long-term planning to maintain or increase the amount of habitat when the hollow trees present today become too old.
Ten years ago, 25 localities with O. eremita were known, while currently this figure is 270, if a locality is defined as a site with records of living adults, larvae, fragments of adult body parts, or excrements situated at least 1 km from other localities.In a recent paper, data were compiled from field inventories conducted in 1993-2003 (Antonsson et al., 2003).Totally, pitfall traps had been used at 401 localities and wood mould sampling at 104 localities.O. eremita was found at about 30% of these localities.All larger Swedish museum collections have been gone through (Antonsson et al., 2003).Research on the ecology of the beetle has been conducted (e.g.Ranius, 2002b).

Switzerland (fig. 9)
During the last few decades, all but one record of O. eremita in Switzerland are from the town of Solothurn.There, the species has been found in lime trees (Tilia spp.) in alleys and in a park near a castle (Vögeli, 2002).There are still many old trees in alleys and parks in the locality, but some are threatened due to conflicts with public safety.One recent record is from the region of Brusio, near the Italian border, where there are hollow willows (Salix spp.) and chestnut trees (Castanea sativa) (P.Audisio, pers.obs.).
There are several old records from other localities in Switzerland (Allenspach, 1970).In the early 20 th century the species was described as "rare, although present throughout the lowlands of Switzerland" (Stierlin, 1900).Data on the specimens in Switzerland's museums and many private collections have been collected.There were no more than 80 specimens collected in Switzerland during the last 150 years.No inventories focused on O. eremita have ever been conducted.Turkey (fig.5) We only know one record of O. eremita from Turkey: in 1994, Dr. Sobotan found the beetle in Keșan, in the European part of Turkey.

Conclusions: the future for O. eremita
In this study, we have collected records of O. eremita from 2,142 localities in Europe (fig.4).However, O. eremita has probably already become extinct from many of these; the beetle has been found since 1990 only at 919 of the localities.Out of these 919, at 79 only excrements have been found and at 96 only remains from dead beetles have been found.For these 175 localities we can not rule out the possibility that the species has already become extinct.On the other hand, there are many unknown localities that have yet to be discovered.Everywhere in Europe it seems that the majority of localities with O. eremita are small and isolated.For that reason we should expect many local extinctions in the future, even though the hollow trees that are left will be protected.This is especially the case in regions where habitat loss and fragmentation have occurred recently (for instance in France, Eastern Germany, Slovakia and Czechia); in Sweden, where the main loss of suitable trees occurred in the 19 th century, O. eremita has already disappeared from some, but not all, of the smaller sites (fig.2).In some countries (such as Denmark), all localities are small and the risk for regional extinction is considerable.In other countries (e.g.France, Sweden, Latvia and Austria) there are also a few larger localities where O. eremita may also survive in the long term if the sites are properly managed.
O. eremita still occurs in almost all European countries but is absent from the boreal region, the British Isles and most of the Iberian peninsula.O. eremita seem to have decreased in all European countries.Relatively high densities of localities occur in Central Europe (northern Italy, Austria, eastern Germany, Czechia and southern Poland), some parts of Northern Europe (south-eastern Sweden, Latvia) and France.Perhaps there are also many localities in the Balkans, but searching efforts have been very low there during the last few decades.In some regions in north-western Europe, the species has become extinct or may occur at a single locality (Norway, Danish mainland, the Netherlands, Belgium, north-eastern France).Bearing in mind the severe loss of old trees in Europe, it is perhaps surprising that O. eremita has not become extinct from larger regions.However, the species can survive in small relict populations over decades, and even if it is doomed to extinction it will take time before the species totally disappears from a region (Ranius, 2000).
O. eremita mainly occurs in habitats that have been used by man for a long time.However, there are also O. eremita localities in forests, such as in Spain, France, southern Italy, the Balkans, Slovakia and Germany.Many of the man-made habitats are destroyed due to changes in agriculture.In Sweden as an example, pasture woodland suffers from forest regrowth due to ceased management, while the abandoned pollarding of oaks in France makes it difficult to produce suitable new trees for O. eremita.The beetle can also obviously survive in urban areas, but in many cases there are conflicts with public safety.
Our compilation of data supports the view that O. eremita is useful as an indicator and umbrella species as everywhere it is confined to hollow treesa threatened habitat.There are a few observations of the beetle in stubs, but there is no indication that O. eremita populations could survive at localities with no tree hollows present.Moreover, the presence of O. eremita indicates a high species richness with many threatened species associated with old trees (Ranius, 2002a).The preservation of O. eremita involves three tasks that are of general importance for nature conservation in Europe today: (1) to preserve those small remnants of natural forest that still exist, (2) to preserve and restore habitats connected with historic agricultural landscapes and (3) to preserve any remaining small pieces of nature in urban areas.Thus, taking the measures needed to protect O. eremita will also contribute to solving many other current problems in nature conservation in Europe.Gronsveld (1907), Houthem (1904), Limmel (before 1892), Maastricht (1876-1903), Oud-Vroenhoven (before 1887), Valkenburg (1902), Wijnandsrade (1946).
Based on examination of the major Dutch private and museum collections.Also the faunistic literature was checked for additional data (Huijbregts, 2003).In total, 23 O. eremita specimens from 14 localities were collected between 1870 and 1946.

Fig. 1 .
Fig. 1.Typical trees harbouring Osmoderma eremita for different parts of Europe: A. Pollarded oaks in hedgerows in western France; B. Oaks in a historical pond-region in Eastern Germany; C. Pastured oak-land in southern Sweden; D. Beech forest in Germany, the tree harboured O. eremita before it was storm-felled; E.An alley with willow trees in a park in Germany.

Fig. 3 .
Fig. 3. Osmoderma eremita and a pitfall trap.The trap consists of a jar placed inside a hollow oak with the opening on the level with the wood mould surface.

Fig. 4 .
Fig. 4. Distribution of Osmoderma eremita in Europe: .Last record before 1950, or the time unknown;.Last record 1950-1989; .Last record in 1990 or later.Larger circles represent records in German federal states where we do not have data for the individual localities.

.
Most of the localities are not in forests but in agricultural landscapes.Forests with O. eremita are normally only small localities situated far (often more than 100 km) from each other.These forests have a different history, for instance: (1) old forests planted by Colbert in the 17 th century in the Forest of Bercé (Sarthe Department) and in the Forest of Tronçais (Allier Department); (2) forests conserved by the Barbizon School of Painters in the Fontainebleau forest during the 19 th century; (3) ancient castle parks (such as Forest of Compiègne in the Oise Department); (4) very old urban parks with old trees (for instance, Strasbourg and Mulhouse); (5) forests that have been grazed by cattle, for instance the Forest of Massane (Pyrénées Orientales)