Catalogue, distribution, taxonomic notes, and conservation of the Western Palearctic endemic hunchback beetles (Tenebrionidae, Misolampus)

Abstract Hunchback darkling beetles of the Ibero-Maghrebian genus Misolampus Latreille, 1807 (Tenebrionidae, Stenochiinae) encompass six species: M. gibbulus (Herbst, 1799), M. goudotii Guérin-Méneville, 1834, M. lusitanicus Brême, 1842, M. ramburii Brême, 1842, M. scabricollis Graells, 1849, and M. subglaber Rosenhauer, 1856. Previously known distribution ranges of the species were delineated using many old records, the persistence of such populations being questionable under the current situation of global biodiversity loss. Additionally, the status of geographically isolated populations of the genus have been the subject of taxonomic controversy. An exhaustive bibliographical revision and field search was undertaken, and the Misolampus collection of the Museo Nacional de Ciencias Naturales (MNCN-CSIC) was revised. The aims are to (i) provide an updated geographic distribution range for the species of Misolampus; (ii) to determine the taxonomic status of controversial populations; (iii) to provide a catalogue for Misolampus; and (iv) to discuss the conservation status of these saproxylic beetles. As a result, a catalogue including synonymies and type localities, geographical records, diagnoses, and information on natural history for all species of Misolampus is presented. The results reveal that the distribution ranges of the species of Misolampus have not undergone a reduction in the last century, and indicate the presence of the genus in areas where it had never been recorded before. The morphological variability of M. goudotii drove the proposal of different taxa that are here formally synonymised as follows: M. goudotii Guérin-Méneville, 1834 = M. erichsoni Vauloger de Beaupré, 1900, syn. nov. = M. peyerimhoffi Antoine, 1926, syn. nov.


Introduction
Species identification is an essential process for almost all biodiversity studies and can constitute a major constraint for conservation evaluation and legislation due to the inherent difficulty of identifying many of the groups, the long time needed for processing the samples, and the extensive taxonomic experience that this process requires (Gauld et al. 2000;Guerra-García et al. 2008;Wheeler 2013;de Oliveira et al. 2020;Saoud 2020). Meeting this goal for megadiverse groups such as insects is often arduous considering the vast number of species that must be identified and the limited number of taxonomists, which make correct identification a very time-consuming process (De Carvalho et al. 2005;Evenhuis 2007;Wheeler 2008;Moore 2011;Yang et al. 2015). It is therefore necessary to create easy-to-use identification tools, such as visually enhanced guides, to overcome the difficulties involved in the identification process (Kirchoff et al. 2011). Easy-to-use tools are also a key instrument for biodiversity study and conservation, since they can be used by both specialists and non-specialists and their implementation improves outcome, thereby facilitating decision-making for conservation actions (Norton et al. 2000;Yang et al. 2015;Rosas-Ramos et al. 2019).
Tenebrionidae is one of the most species-rich families of beetles, with approximately 20,000 species worldwide and many more taxa yet to be described (Bousquet et al. 2018). The large number of species, combined with the high morphological diversity that this family exhibits (Matthews et al. 2010), can hinder species identification of tenebrionids. Thus, providing easy-to-use, photographically illustrated identification tools can greatly facilitate data acquisition on this group of beetles (e.g., Matthews and Bouchard 2008;Pérez-Vera and Ávila 2012). The problem represented by the local absence of taxonomists and lack of adequate identification tools for non-specialists, is often reflected in a general lack of appropriate identifications, use of not-actualised names, or worst, inclusion of misidentified specimens in scientific collections or databases (Vilgalys 2003;Guerra-García et al. 2008;Kholia and Fraser-Jenkins 2011;Shea et al. 2011). This situation renders Tenebrionidae collections of little use for any scientific purpose, as it can be easily recognised by their poor representation in biodiversity databases (e.g., GBIF -Gaiji et al. 2013). One example of this problem is represented by the saproxylic hunchback darkling beetles of the genus Misolampus Latreille, 1807, paradoxically one of the better studied genera of Tenebrionidae at taxonomic and phylogenetic levels in the Western Palearctic Region (Palmer 1998;Palmer and Cambefort 2000).
Despite database records shortfall, the distribution ranges of the species of Misolampus are relatively well known (Palmer 1998). Nevertheless, a few new eccentric geographical records have recently been published, suggesting that the distribution areas might be larger than what is currently recognised (Ibáñez Orrico 2002;Pérez and López-Colón 2010;Novoa et al. 2014). Regretfully, many of the specimens used to delineate the distribution areas of the species were collected between 50 and 100 years ago (Palmer 1998). The continuity of those populations through time, under the current scenario of drastic increase in land-use and climate change is, however, questionable (Vanwalleghem et al. 2017), all the more so given the saproxylic nature of these species, which often can lead to conservation issues (García-López et al. 2016).
In the light of these considerations, first, we aimed to provide an updated geographic distribution range for all the species of Misolampus, to evaluate their persistence in the areas where they were reported. For this purpose, we undertook a thorough bibliographical revision, an exhaustive field search, and we revised the Misolampus collection of the Museo Nacional de Ciencias Naturales (MNCN-CSIC) in Madrid (Spain). Secondly, and as a result of the field data collection, we aimed to determine the taxonomic status of geographically isolated populations of the genus, including those that have been the subject of taxonomic controversy (Reitter 1917;Español 1949;París García et al. 2011). Thirdly, with all that information, we aimed to provide an easy to use, photographically illustrated catalogue for Misolampus, and to discuss the potential threats and conservation status of the species of the genus.

Materials and methods
Field work to locate Misolampus was carried out by members of the research team for two periods, a non-intensive period from 1982 to 2000 in which specimens were collected, georeferenced, and dry-mounted for their morphological study, and a more intensive period from 2001 to 2013, with additional collections in 2019-2020, aimed to detect changes in populations previously known from records dating from the 19 th and 20 th centuries. Field data collection was carried out along most of the areas where the presence of the genus was documented (Spain, Portugal, and Morocco). Information on the location of previously known populations was obtained by undertaking an exhaustive bibliographic revision and by reviewing the Misolampus collection held at the MNCN (Museo Nacional de Ciencias Naturales, Madrid, Spain).
We studied 1304 specimens representing all known taxa of Misolampus (812 collected before 1945, and 492 collected after 1982). Of those, 355 specimens are preserved in ethanol, and 949 specimens dry-mounted (Table 1), all forming part of the entomological collections of the Museo Nacional de Ciencias Naturales (MNCN-CSIC, Madrid). The list of examined specimens is included in the corresponding paragraph of the species catalogue. Collectors are specified when different from authors or members of the research team; collector name is indicated for old collections only when printed in the labels; "ex." or "exx." is used to abbreviate "specimen" or "specimens".
Unresolved taxonomic issues, such as the validity of subspecies within the North African taxon, the specific assignation of the populations from Algarve (Reitter 1917;Español 1949), and taxonomic status of the isolated population from Ifni (Morocco) (París , were addressed by comparing these problematic populations with specimens from near type localities, or from areas of undisputed taxonomy. Distribution maps based on current data represent the extent of occurrence of each species following a relaxed modification of IUCN criteria (IUCN 2012). We performed species distribution models (SDMs) to obtain the potential distribution of each species (Kamiński et al. 2017). We used Maximum entropy algorithm (MaxEnt) (Elith et al. 2006(Elith et al. , 2011 and the set of WorldClim v 2.0 environmental variables, with a resolution of 30 s (~ 1 km) (Fick and Hijmans 2017). The SDMs were modelled considering the studied specimens as presences and generating pseudo-absences fol- Table 1. Specimens of Misolampus studied. Number of specimens by preservation mode (ethanol or dry-mounted) and date of collection (before 1945 or after 1982). The total number of specimens of each species is also provided.

Species
Before 1945  lowing Gil-Tapetado et al. (2018). This methodology creates a preliminary presenceonly coverage model based on the maximum and minimum values of each variable. Areas with environmental values that fall out of the maximum and minimum range were considered liable to be pseudo-absences. This is considered as a more reliable approach than generating pseudo-absences entirely at random. SDMs were run 50 times, with random test percentage set to 25 and "subsample" as the sampling technique. The model was validated by estimating the area under the curve (AUC) value (Fielding and Bell 1997 To obtain morphological data, dry-mounted specimens were examined under a stereomicroscopy. Specimen length was measured in dorsal view as the distance between the anterior margin of the pronotum and the elytral apex (ignoring elytral convexity). The head was excluded from measurement since it is usually directed ventrally. Maximum width was measured as the distance between the outer edges of the elytra at approximately three-fourths of the elytral length, also in dorsal view. Photographs of live specimens were taken with a Nikon digital camera. Extended depth-of-focus images of dry-mounted specimens, were taken on a Leica M165C stereo-microscope, with a digital camera Leica DFC450, using the LAS X software from Leica Microsystems.  40°17'29.7"N, 04°21'11.9"W, 4-I-2009: 5 exx.; Villalba: 1 ex.

Species
Diagnosis. Total length 6.6-12 mm (Reitter 1917;Español 1949;López-Pérez 2014a). Easily recognisable by its general shiny appearance and small size. Misolampus gibbulus presents acutely protruding prothoracic anterior angles, strong pronotal punctation, deep, and densely covering most of its surface; elytra with well-marked deeply excavated striae, with large and deep punctation, and shiny interstriae intervals often with additional series of punctures ( Fig. 1A-D). Female genitalia figured by Palmer (1998). The species presents marked variability on the development and depth of the elytral and pronotal sculpture. Pronotal punctation is usually less developed, and elytral striae shallower, not so excavated, in populations of southwestern Portugal (Faro district) (see taxonomic discussion).
Our new records considerably expand the known distribution of M. gibbulus. In addition to previously published data, we add new records for the district of Évora and Portalegre in Portugal, and from the provinces of Ávila, Badajoz, and Toledo in Spain; together with numerous localities for some provinces represented by a few records, such as Cáceres, Ciudad Real, and Madrid. With the addition of these records, the distribution of M. gibbulus seems to be more or less continuous along the southern slopes of the Sistema Central: from Cáceres and Ávila to Madrid, along both slopes of Montes de Toledo and Sierra Morena, and in a more or less extended area in southern Portugal, from Évora to Serra de Monchique in the Algarve region. The Guadalquivir river basin seems to conform the southeastern distribution limit for the species (Fig. 2A). The potential distribution map identifies southwestern Iberia as a high suitable area for the species occurrence, together with some areas where the species does not occur: the Betic Mountain ranges, the Balearic Islands, and northern Africa (Fig. 2B).
Notes on natural history. Misolampus gibbulus is a low altitude species, ranging from 4 to 1278 m a.s.l., although 81% of the populations recorded are located below 800 m of altitude. Geological substrates are very diverse across its distribution area, but mostly siliceous, including sandstones, gneisses, granites, and schists, which generate acid soils (see Vera 2004;Oliveira andQuesada 2019a, 2019b). It occupies mainly the meso-Mediterranean thermoclimatic belt and, to a lesser extent, the thermo -(at the southermost portion of its range) and supra-Mediterranean (on a narrow northern strip), with ombrotypes from dry to humid (Rivas-Martínez 1987;Rivas-Martínez et al. 2002;Rivas-Martínez 2007). It is found over an extensive variety of forest and subforestry habitats, including both coniferous (Pinus L.) and broadleaved trees (Quercus L., Fraxinus L.), and also dense shrublands of Cistus L. ("jarales"), Retama Raf. and Cytisus Desf. ("retamares") ( Fig. 1E, F). The species also occupies areas densely reforested with native and non-native Pinus and Eucalyptus L'Hér. (Cabral 1983), as well as open man-modified agroforestry systems ("dehesas" of Quercus) and montane agrosystems with olive and chestnuts trees (Olea europaea L. and Castanea sativa Mill.) (see Ladero 1987;Valle 2003;Costa Tenorio et al. 2005).
Misolampus gibbulus is commonly found under bark or within decomposing dead logs and stumps of pines (mainly of Pinus pinea L. and Pinus sylvestris L.), including reforested areas (especially Pinus pinaster Aiton), where they appear to be particularly common. It is also found in dead or old trunks of perennial or deciduous oaks (Quercus ilex L., Quercus suber L., Quercus pyrenaica Willd. and Quercus faginea Lam.), under the dry layers that cover roots and thick stems of Cistus ladanifer L. and Cistus laurifolius L., and at the base of brooms, mainly Cytisus scoparius (L.) Link and Retama sphaerocarpa (L.) Boiss. Occasionally found under loose bark or at the base, among decaying wood of standing Eucalyptus trees, and also in rotten Eucalyptus stumps (Cabral 1983;López-Pérez 2014a;pers. obs.). Sometimes found also under stones in open areas, near forest or shrub patches. Almost all these habitat locations are coincident to those described by López-Pérez (2014a) for the province of Huelva. Its food source is unknown (as in the other species of the genus), although Barreda (2018) pointed out mistakenly that it is a moss eater (quoting Español 1949 andBujalance de Miguel 2015); nevertheless, Español (1954b) commented that the species of Misolampus are saprophagous, without further specification.
Misolampus gibbulus has been found in microsympatry with M. scabricollis along western Sierra Morena (Huelva), northern Extremadura (Cáceres), Montes de Toledo (Toledo) (Fig. 1E), and southern slopes of the Sistema Central (Madrid, Ávila, Toledo), and with M. subglaber at the eastern end of Sierra Morena (Jaén) (pers. obs.). Adults can be found across most of the year (Cárdenas Talaverón and Bujalance de Miguel 1985; López-Pérez 2014a; Barreda 2018) but according to our observations they are more easily encountered during the wetter months (October to May).

Misolampus goudotii Guérin-Méneville, 1834
Misolampus goudotii Guérin-Méneville, 1834: 28. Terra typica: "trouvée à Tanger... ...à trois lieues de Tanger, sur les bords d'une rivière, dans le tronc d'un olivier." Vauloger de Beaupré (1900), Reitter (1917), Antoine (1949), and Español (1949) among others, wrote the species name with a single final -i. Solier (1848)    Diagnosis. With a total length from 10 to 14 mm, this is the largest species of the genus (Vauloger de Beaupré 1900;Reitter 1917;Antoine 1926;Español 1949). This species is well characterised and isolated within the genus Misolampus by the following traits: fore angles of the prothorax not protruding, almost rounded, forming an obtuse angle at apex; lateral surface of pronotum shallowly rugose, with the rugosity progressively erased towards the dorsal areas that appear smoother, propleural punctation fine and often erased; elytra with longitudinal series of small elongated tubercles, more apparent on the sides of the posterior half of the elytra (Español 1949(Español , 1954aPalmer 1998) (Fig. 3A-C). Female genitalia figured by Palmer (1998). Specimens from the Balearic Islands have been studied karyologically Petipierre 1986, 1989;Juan et al. 1993;Pons et al. 1993;Pons 2004), presenting a chromosome number of 20 (2n) Petitpierre 1986, 1989). There is marked geographical variability on the sculpture and shape of pronotum and propleurae, and on the development of elytral tubercles (Vauloger de Beaupré 1900; Antoine 1949; Español 1954a) ( Fig. 3A-C). Specimens from northern Morocco (excluding the Tingitane Peninsula), Algeria and the Balearic Islands, present a well-developed and evident elytral tuberculation that may form rugose ridges (Fig. 3A). On the other extreme, elytral tubercles are reduced in the Rif and Atlas populations (Fig. 3B), to become almost completely absent in the specimens from Sidi Ifni (Fig. 3C). Pronotum sculpture is formed by fine spaced punctures intermixed with granules, much denser on the sides in the Balearic Islands population (Fig. 3A); pronotal rugose areas are more marked and extended in the specimens from the High Atlas (Fig. 3B), and formed by sparse punctation, without granulose areas, in the specimens from Ifni (Fig. 3C). The anterior edge of the pronotum, in the Rif and Balearic populations, is straight at the middle, while it appears convex in the populations from the High Atlas (Antoine 1949). The geographic distribution of this variability has been the subject of taxonomic discussion resulting in the proposal of different taxa, here formally synonymised (see synonymic list, and taxonomic discussion).
The studied materials include recent and old records of populations from the Balearic Islands (Mallorca and Menorca) and from the Moroccan regions of Meknès-Tafilalet, Souss-Massa-Drâa, Tanger-Tétouan, and Taza-Al Hoceima-Taounate. Recent data are available from all four regions, with a large number of localities from the Rif, and less numerous in the Middle and High Atlas. Among these records, we emphasise the re-dis- covery of the population from the province of Sidi Ifni, in January-2020, 85 years after its original finding, by F. Martínez de la Escalera in 1934and 1935). The latter is a singular population, apparently isolated in the arid mountains near Ifni; its closest known population is located in the Western High Atlas, ca. 250 km to the northeast (Fig. 4A). The potential distribution map locates high suitable areas for this species along the mountain ranges of northwestern Africa, the coastal and mountain areas in the Tingitane peninsula, and along the coast of Rabat-Salé-Kénitra region. It also identifies areas where the species does not occur as high suitable, including sothwestern Iberia, the Balearic Islands and Sardinia. The Ifni population is located in a very fragmented area of high suitability, suggesting a possible Pleistocene relict status for this population (Fig. 4B).
Notes on natural history. Misolampus goudotii is widely distributed over northwestern Africa, though restricted to mountain ranges and adjacent areas: Rif, Middle Atlas, western High Atlas, Beni Snassen mountains, southwestern foothills of the Anti-Atlas (Morocco) and Tellian Atlas (Algerie) (Fig. 4). Altitudinal range in the Maghreb from 2 to 2064 m a.s.l., with 70.5% of records above 800 m of altitude (62% above 1000 m). In the Balearic Islands its altitudinal range is lower, between 15 and 718 m a.s.l., but the species is found mainly in areas of mountainous topography (e.g., Serra de Tramuntana in Mallorca). It inhabits a wide range of geological substrates, both acid and basic, from plutonic and metamorphic types to calcareous and dolomitic rocks (see Michard 1976;Vera 2004;Oliveira andQuesada 2019a, 2019b). Misolampus goudotii is a euryecious species that occurs at infra-, thermo-, meso-and supra-Mediterranean thermoclimatic belts, in regions with ombrotypes from arid to hyperhumid (Benabid 1985;Rivas-Martínez 1987;Le Houerou 1989;Rivas-Martínez et al. 2002;Rivas-Martínez 2007;Sebbar et al. 2013 Benabid 1982Benabid , 1984Benabid , 1985Benabid and Fennane 1994;Bolòs 1997;Charco 1999;Benabid 2000;Taleb and Fennane 2019). It also occurs in areas reforested with pines (pers. obs.) (Fig. 3D, E). The population of Ifni inhabits mountains (620-1225 m of altitude) at the infra-Mediterranean thermoclimatic belt, probably affected by the proximity to the Atlantic Ocean and consequently by the presence of some degree of cryptic precipitation (Géhu and Biondi 1998). The vegetation of the area is dominated by open forest of Argania spinosa (L.) Skeels, with sparse cactiform and arbustive Euphorbia L. (Médail and Quézel 1999;Ruiz and García-París 2015), and large areas covered by formerly cultivated Opuntia Mill (Fig. 3F).
In the Moroccan Rif, M. goudotii is often encountered under bark, inside fallen logs or stumps, and at the base of dead old oaks (perennial: Q. ilex, Q. suber; deciduous: Q. canariensis, Q. faginea and Q. pyrenaica), arbutus trees (Arbutus unedo L.), wild olive trees (O. europaea var. sylvestris), pines (P. nigra, P. pinaster, P. halepensis), firs (Abies maroccana), and cedars (Cedrus atlantica), as already reported partially by Vauloger de Beaupré (1900), Cobos (1955Cobos ( , 1961, and Benyahia et al. (2015Benyahia et al. ( , 2016. They can also be found under bark of standing dead trees (A. maroccana, C. atlantica, Q. suber, Q. pyrenaica). In the Middle and High Atlas, it is usually found under bark and inside large decaying logs of Q. ilex (Antoine 1926), but also in old decomposing logs of P. nigra and C. atlantica. Mouna and Arahou (1986) collected the species on thuya (Tetraclinis articulata) in the Korifla Valley (northwestern Morocco). Sidi Ifni specimens were found within crevices in old dead logs of Argania spinosa, almost buried on the ground of a steep slope (Fig. 3F). Nearby standing dead trunks were occupied by Nesotes tuberculipennis villarubiai (Español, 1943) as described by Nabozhenko (2015). In Algeria, they have been found under bark of fallen pines (Vauloger de Beaupré 1900). In Menorca, it has been found in oak forests of Q. ilex, under bark or under stones and leaf litter (Cardona Orfila 1875), and in Mallorca it is frequent in decaying wood of fallen pines (P. pinea) and old oaks (Q. ilex) (Fig. 3D).
Adult specimens are often found in aggregations. We found aggregations of approximately 15 specimens close together in a single large rotting pine log in Mallorca. We also found aggregations of M. goudotii together with Helops insignis maroccanus (Fairmaire, 1873) (Tenebrionidae, Helopinae) under bark of dead trees of Q. suber, A. maroccana and C. atlantica in the Rif Mountains. Whitehead (1993) relates the finding on two occasions of groups of individuals between the annual rings of dead pines (P. halepensis) in active colonies of ants of the genus Messor Forel, 1890 and of the species Monomorium bicolor Emery, 1877 (probably another species of Monomorium Mayr, 1855, since the invasive M. bicolor is not present in Balearic Islands; Salata et al. 2019).
Adults are present all year round, but they are more commonly seen in winter and spring in middle and low elevations (Vauloger de Beaupré 1900;Español 1967;pers. obs.), and in summer at higher altitude (Antoine 1926), however, Moragues (1889) mentioned collections during the summer in Mallorca. Blue dots correspond to the species records, including both recent and old, as well as previously published data. The population from Ifni remains isolated from the main distribution range, by a distance of ca. 250 km B potential geographic distribution of Misolampus goudotii: Red indicates high suitable areas, and blue, areas of low suitability. Species distribution model was generated using MaxEnt v 3.4.1 (Elith et al. 2006) and the set of WorldClim v 2.0 (Fick and Hijmans 2017) environmental variables.
The material we studied includes recent representation from the provinces of León and Ourense in Spain, and from the Porto district in Portugal. To date, the species is only known from ten localities (Fig. 6A). The potential distribution map locates high suitable areas for this species mainly in the northwestern region of the Iberian Peninsula (Fig. 6B).
Adults are usually found at the base of trees, under bark, under stones or in leaf litter of forests (Español 1956;Español and Comas 1981), but also under stones in mountain shrub-lands (pers. obs.). It has also been found in densely reforested areas with P. pinaster, and also in chestnut groves (C. sativa). It has not been recorded in sympatry with any other species of Misolampus, but it has been found in company of Coelometopus clypeatus (Germar, 1813) (Tenebrionidae, Cnodalonini) (Español and Comas 1981). According to the limited available data, adults seem to be present all year round.
Materials studied by us include specimens from all previously reported areas except Mallorca (not searched for). Records are recent for all localities except for those from the Murcia region (Sierra Espuña). The potential distribution map (Fig. 8B) shows that highly suitable areas are primarily located in the coasts and mountain ranges of the south of Almería, Granada, and Málaga and the northwest of Mallorca island, coinciding with the recorded presence of the species. The northwestern coast of the Iberian Peninsula and the mountain ranges of Northwestern Africa are also pointed as areas of high suitability.
Commonly found under bark or inside dead logs and stumps of pines (P. halepensis, P. pinaster and P. nigra), and oaks (Q. ilex), or under stones in forests and shrublands. Occasionally found under the lose bark of standing live isolated Eucalyptus trees. In the island of Mallorca, it has been found in oak forests (Q. ilex), under bark or under stones and leaf litter (Español 1949(Español , 1954a. Adults can be found in autumn, winter, and spring, with no records in the summer months of August and September.
Geographic distribution. Endemism of Portugal and Spain (Löbl et al. 2008) (Fig. 10). Bibliographic records are scarce, covering a large portion of the centre and western areas of the Iberian Peninsula, including Aveiro, Bragança, Alto Douro, and Guarda in Portugal, and the provinces of Ávila, Cáceres, Huelva, Madrid, Ourense, and Segovia in Spain (Graells 1849(Graells , 1851a(Graells , 1851bSeidlitz 1867;Paulino de Oliveira 1894;Reitter 1917;De la Fuente 1934-1935Español 1949;López-Pérez 2014a;Novoa et al. 2014). Published records of M. scabricollis from Sierra Espuña (von Heyden 1884), Murcia (De la Fuente 1934-1935 and Sierra de Alcaraz (Reitter 1917) are erroneous and probably correspond to M. subglaber. Misolampus scabricollis is widely distributed throughout the main mountain ranges of the central and western areas of the Iberian Peninsula (Sistema Central, Sierra de Gata, Sierra de Guadalupe, Montes de León, Montes de Toledo, eastern Sierra Morena, Serra da Estrêla), with an apparently isolated population in the western extreme of Sierra Morena (Sierra de Aracena, province of Huelva) separated ca. 240 km from the eastern population of this same mountain system (Fig. 10A).
All previously existing records except those of Huelva and Ourense, correspond to data published more than 70 years ago. The material studied or collected by us, includes records from all provinces of Spain previously reported in the literature, except from Ourense, with the addition of new records from Castelo Branco and Portalegre in Portugal, and from the provinces of Burgos, Ciudad Real, Guadalajara, Salamanca, Toledo, and Zamora in Spain. All these new records correspond to recent observations, together with old ones for Ciudad Real and Salamanca. The potential distribution map for this species (Fig. 10B) locates the main high suitable areas in central and western regions and along mountain ranges of the Iberian Peninsula. The SDM does not consider the isolated population of Sierra de Aracena as present in a high suitability area.
According to our observations, M. scabricollis is usually found inside dead and decaying tree trunks, or under bark, usually in standing or lying pine logs, oaks, and chestnut trees. These observations are coincident with the few disperse available data on the habitat of this species (Graells 1851a(Graells , 1851bLópez-Pérez 2014a). Areas covered by dense bushes of Q. pyrenaica and Q. ilex (recovering after fires or logging) are also frequently used by this species. Misolampus scabricollis can also be found in areas reforested with pines, and under stones, small pieces of wood, or inside tight clusters of branches, in shrub areas dominated by Cytisus scoparius, C. oromediterraneus, and less frequently by Cistus ladanifer (Fig. 9C-F). They are usually more easily found on logs and under stones at the edge of dense forests, but they can also be found deep inside the forest or in nearby grasslands. This species is usually found forming small groups of 2-21 specimens in a single log. Graells (1851aGraells ( , 1851b reported groups of five or six specimens per log in the Guadarrama Mountains. According to Graells (1851aGraells ( , 1851b, when disturbed they pretend to be dead (thanatosis) and expel an unpleasant light odour.
Misolampus scabricollis has been found in microsympatry with M. gibbulus along western Sierra Morena (Huelva), northern Extremadura (Cáceres), Montes de Toledo (Toledo) and southern slopes of the Sistema Central (Madrid, Ávila, Toledo) (Fig. 1E), however, M. scabricollis is usually found at higher altitudes than M. gibbulus. Adults can be found across most of the year, but are more easily encountered during the wetter, colder, months (October to May). It is often found in company of Coelometopus clypeatus in old chestnut trunks.

Misolampus subglaber Rosenhauer, 1856
Misolampus subglaber Rosenhauer, 1856: 204. Terra typica: "in der Sierra de Ronda". Diagnosis. Total length 10-12 mm (Reitter 1917;Español 1949). Species clearly characterised by the combination of the following traits: smooth silky appearance; antennae graceful, reaching the base of pronotum; pronotal punctation very fine and sparse on the disc, somewhat stronger and denser to the sides; elytral punctation very fine and irregular, not forming longitudinal series of points or striae (Reitter 1917;Español 1949;Palmer 1998) (Fig. 11A, B). Female genitalia figured by Palmer (1998). The species has been studied karyologically and presents 2n = 20 chromosomes (Palmer and Petitpierre 1997). Morphological variability within this species seems limited to the depth and density of pronotal punctation, and it does not appear geographically structured.
The material studied or collected by us includes specimens from all provinces reported in the literature, except from Valencia. In addition, we studied material from the provinces of Córdoba, Ciudad Real and Cuenca; specimens of Ciudad Real and Cuenca are represented by recent collections (2012). According to these data, M. subglaber is located in the Betic Mountain range (Sierras del Campo de Gibraltar, Serranía de Ronda, Sierra Nevada, Sierras de Tejeda and Almijara, Sierra de Cazorla, Sierra de  Alcaraz, Sierra de Cartagena), eastern and central Sierra Morena mountain range, and two apparently isolated populations in the Southern Iberian mountain range (Serranía de Cuenca and Sierra de Malacara, separated between them by ca. 150 km). There is a gap of records in the arid regions of the southeastern end of Spain, throughout the provinces of Almería and southern Murcia, including the eastern half of Sierra Nevada and Sierra de Filabres. The record from Cartagena, Murcia (Reitter 1917), requires further confirmation (Fig. 12A). The potential distribution map identifies the Betic Mountain ranges as the most suitable area for the species. The coastal areas of Almería, Granada, and Málaga provinces are however not included as very suitable. The southern Iberian Plateau and the northwestern African mountain ranges are also suggested as areas of high suitability for the species occurrence (Fig. 12B).
The general distribution area occupied by M. subglaber (Fig. 12) is largely coincident with that of M. ramburii (Fig. 8), however they have not been found in microsympatry, a possible indication of ecological segregation between them. Adults are mainly active in fall, winter and spring, but can be found all year round (pers. obs.). Large larvae and pupae have been observed at the end of August in Valencia (Ibañez Orrico 2002).
Identification key for adult specimens of the genus Misolampus (modified from Español 1949) 1 Elytra with series of deep to shallow punctures forming strongly to almost erased, excavated striae; additional series of punctures often present on the elytral intervals (Fig. 14A, B). Small size ( Elytra with shallow to almost erased striae, often showing longitudinal series of more or less developed elongated tubercles, or sometimes shallow fossae on the interstriae, better marked on the second half of the elytra and on the sides (Fig. 14D). Medium size (10-14 mm), long antennae (Fig. 3)  Pronotum sculpture formed by deep to shallow, dense or sparse, never confluent, well-defined punctures which cover all the pronotal surface, including the lateral sides, which can present somewhat more confused punctation, but not forming rugose areas (Fig. 16B). Elytra covered by dense punctures somewhat confused or partially erased at the disc. Pronotum sculpture formed by deep, dense, well-defined punctation. Antennae relatively short, not reaching the base of pronotum (Fig. 5). Small size ( Accordingly, Antoine (1949), followed by Español (1949Español ( , 1954a, considered that the morphological traits used to separate the three described North African taxa were insufficient, and treated them as subspecies (M. g. goudotii, M. g. erichsoni, and M. g. peyerimhoffi). Español (1953Español ( , 1967 went further, and suggested that M. g. erichsoni should be included in the synonymy of M. goudotii, while Kocher (1958) indicated that all three taxa were just local varieties of a unique taxon. However, the criterion of Español (1953Español ( , 1967 and Kocher (1958) was not followed by subsequent authors (Löbl et al. 2008). Meanwhile, the morphological variability implied by Martínez de la Escalera and Vauloger identifications (in litt.), raises further problems for the characterisation of North African populations as subspecies.
Characters initially used for separation of the North African taxa were: pronotal punctation, shape of the anterior margin of the pronotum, shape and sculpture of the propleurae, and width of the second interstria on the elytra (Vauloger de Beaupré 1900;Antoine 1949;Español 1954a). A close examination of the specimens studied by Vauloger and Escalera (see materials and methods) reveals that some of the Rif specimens present intermediate traits between the specimens of the Tingitane Peninsula (Tanger, western Rif ) and those from the Middle and High Atlas (Fig. 3B). At the same time, specimens from Ifni (Fig. 3C), roughly located at the coastal western end of the Anti-Atlas mountains, are more similar morphologically to the specimens from the Rif than to those geographically closer from the High Atlas.
Morphological similarity between specimens located in geographically isolated areas, separated by hundreds of kilometres, reflects that the morphological diversity documented across populations, lies within the phenotypic variability of a single evolutionary entity, rather than being a consequence of ancient isolation processes (Montori et al. 2008;Gonçalves et al. 2009). Alternatively, the observed morphological diversity could be consequence of a rapid response to recent geographic isolation of local populations subjected to local strong selective pressures (Velo-Antón et al. 2007). These hypotheses could be tested by genetic analyses, since the phylogeographic outcome of these two processes would be markedly different in each case: Geographically unstructured nuclear marker networks, accounting for the lack of geographic structure at the morphological level, with or without deep mtDNA lineage differentiation in the first case (Recuero and García-París 2011); or alternatively, geographically congruent nuclear and mtDNA marker phylogeographic patterns, with recent, shallow, multiple mtDNA lineage differentiation, accounting for the recency of the isolation processes, not enough to allow sorting out morphological differences, in the second case (Vörös et al. 2006;Rodríguez-Flores et al. 2017). However, none of these processes is consistent with the recognition of independent evolutionary units within North African Misolampus, and therefore we consider necessary to synonymise all three subspecies (M. goudotii Guérin-Méneville, 1834 = M. erichsoni Vauloger de Beaupré, 1900, syn. nov. = M. peyerimhoffi Antoine, 1926, syn. nov.), retaining thus a single North African species: M. goudotii Guérin-Méneville, 1834. The morphological similarity between the Balearic specimens and the Eastern Moroccan and Algerian ones drove Palmer and Cambefort (2000) to consider a very recent origin for the Balearic populations, possibly as a consequence of human-mediated dispersal.
There has been some confusion in the identification of specimens of Misolampus from southern Portugal (Serra de Monchique). Specimens from that region often present not strongly marked elytral striae, and relatively smooth thoracic impressions (Fig. 1A, B), resembling M. ramburii (Fig. 7A, B). However, a close examination of the Serra de Monchique specimens (Foia, Monchique, São Marcos da Serra) indicates that based on all other characters (mainly, prothorax morphology, and pronotal punctation), they correspond to M. gibbulus. The morphological differentiation shown by the population of M. gibbulus from Serra de Monchique with respect to other populations of the species, is quite marked, and led Reitter (1917), Paulino de Oliveira (1894) and De la Fuente (1934-1935 to mention erroneously the presence of M. ramburii in Serra de Monchique. A similar situation occurs within M. ramburii. Specimens from populations of Granada (Sierras de Contraviesa and Huétor) have smoother pronotal sculpture, and less marked, almost absent elytral striae (Fig. 7B), while specimens from Almería show stronger sculpturing in elytra and pronotum, with elytral striae, marked by a series of aligned punctation, faint, but visible (Fig. 7A). This contrasting variation is probably the reason Español (1963) reported an unidentified species of Misolampus from the Sierra de Contraviesa. Lack of elytral striae made these specimens key to M. subglaber, M. lusitanicus, or M. scabricollis using Reitter's (1917) identification table, but other characters, including pronotal structure, allow for an easy separation.
These evident patterns of morphological differentiation within M. ramburii, M. gibbulus, and M. goudotii may reflect a relatively recent history of isolation across populations, probably consequence of the existence of multiple isolated Pleistocene refugia (Abellán and Svenning 2014), as proposed for other flightless Iberian Coleoptera (Sánchez-Vialas et al. 2020). In any case, these hypotheses require phylogeographic analyses to be properly tested.

Historical population continuity and current conservation status
Species of Misolampus have often been considered to present allopatric or, at most, parapatric distributions (Palmer 1998;Palmer and Cambefort 2000). However, old records of Misolampus are, in most species, scarce and unevenly distributed. Indeed, by filling large gaps where no records were present, the newly gathered specimens allow for a better understanding of the distribution patterns of all species.
Our data show some level of sympatry among several species pairs (i.e., M. gibbulus -M. scabricollis, M. ramburii -M. subglaber), even with cases of microsympatric distribution. These levels of sympatry among ecologically similar, phylogenetically closely related taxa are not common because of demographic processes such as competitive exclusion (Hardin 1960;Waters et al. 2013). Assuming the existence of ecological niche overlap among species pairs of Misolampus, areas of sympatric distribution can be explained by simultaneous colonisation from their respective glacial refugia, rapidly spreading into areas with favourable habitats while population densities are still very low, allowing for the establishment of two species (Recuero and García-París 2011;Escoriza et al. 2016;Yackulic 2017). In this way, areas traditionally considered glacial refugia in the Iberian Peninsula (e.g., southern Portugal, Atlantic Coasts of Galicia and Northern Portugal, southeastern Spain) Sánchez-Montes et al. 2018), where population sizes would have remained high, and thus favouring processes as competitive exclusion, are typically inhabited by a single species of Misolampus. The species distribution models show that the species of Misolampus present almost complementary potential distributions, supporting the hypothesis that current sympatry areas are the result of recent contact among taxa. The map including highest suitability areas (suitability > 0.7) for all the Iberian species combined (Fig. 13), shows that most of the high suitable areas do not overlap. Species suitable areas remain mainly restricted to the following regions: M. gibbulus in the southwest, M. lusitanicus in the northwest, M. ramburii in the southern coasts, M. scabricollis over the northern Iberian Plateau, and M. subglaber in the southeastern areas of the Iberian Plateau and along the Betic Mountains.
Additionally, our results indicate the presence of the genus in geographical areas where it had never been recorded. The absence of Misolampus from most part of the Sistema Ibérico mountain chain is particularly striking, considering the huge extension of favourable forest habitats. The recent finding of M. subglaber in the province of Cuenca, as well as the published record from the province of Valencia (Ibañez Orrico 2002), suggests that further populations could be discovered with more intensive sampling, at least in the southern parts of the Sistema Ibérico. Similarly, our records of M. scabricollis from the provinces of Burgos and Guadalajara are relatively close to the Sistema Ibérico mountains, where the species could be present, but still undetected. Similar cases of long undetected presence of arthropod species in the Sistema Ibérico have been recently published (Valladares et al. 2000;Pérez-Onteniente et al. 2015;Ruiz 2015;Recuero and Rodríguez-Flores 2019).
Field data collection, although essential, has the disadvantage of being limited across space, time and taxa, which can constitute a constraint for biodiversity monitoring and conservation (Kuussaari et al. 2009;Meineke et al. 2019). Lack of information on changes in biodiversity through time and on the direction of these changes can make it difficult to identify and counteract negative impacts derived from disturbances (Magurran et al. 2010). However, scientific collections hold in a single location an    2020). These collections provide data on taxon distributions over a vast time, offering a unique perspective on species response to habitat loss and fragmentation, land use intensification or climate change, thus providing critical information to reconstruct species decline and develop conservation strategies (Ponder et al. 2001;Suarez and Tsutsui 2004;Grixti et al. 2009;Doadrio et al. 2019).
The way scientific collections were gathered and the form in which they have been preserved, offer a vast array of possibilities for past-present comparisons in this era of biodiversity loss (Short et al. 2018). Large entomological collections are often formed by the addition of multiple smaller collections (Cambefort 2006;Doadrio et al. 2019). Each taxonomist's collection is a summary of the general biodiversity knowledge at the time, for each of their groups of study. In this sense, scientific collections represent temporal windows opened to a now unreachable past biodiversity, and access to them should be essential and promoted (Mantle et al. 2012;Short et al. 2018).
The saproxylic nature of Misolampus calls into question their conservation status, since saproxylic beetles have been identified as a highly threatened animal assemblage due to habitat loss derived from logging and the decline of veteran trees throughout the landscape (Davies et al. 2008;Ricarte et al. 2009;Nieto and Alexandre 2010;Marcos García and Galante 2013;García-López et al. 2016;García et al. 2018). Despite the potential threats to which the species of Misolampus can be subjected to, their current level of threat has not been evaluated within the frame of the regional IUCN Red List of Mediterranean saproxylic beetles .
However, our comparison of historical data with recent records to assess the current population trends of the species of Misolampus, reveals that their distribution ranges show no reduction in the last century, since these species currently persist in most areas of historical occurrence. This fact, combined with the addition of new recent records for some of the species, enables us to state that, from a general perspective, the species of Misolampus are not in decline, but rather seem to exhibit an adequate conservation status. This status could be further guaranteed, because the distribution range of all species of Misolampus include numerous protected areas (National and Natural Parks, Natura 2000 protected areas; see https://www.miteco.gob.es/es/biodiversidad/servicios/banco-datos-naturaleza/informacion-disponible/ENP.aspx), which could ensure to some extent the long-term persistence of these saproxylic beetles, if combined with the implementation of adequate agroforestry practices, consistent with the general strategies of saproxylic arthropods conservation from the Mediterranean forests ecosystems (Sánchez Martínez et al. 2012;Marcos García and Galante 2013;García et al. 2018).
Considering the habitat specificity of Misolampus, disjunct distribution records such as Ifni for M. goudotii (Fig. 4), or Cuenca and Valencia for M. subglaber (Fig. 12), can involve threats for the species conservation, derived from local population extinctions, which can be irrevocable in the case of isolated populations. However, disjunct distributions might be not only the result of a reduction of the species range (Teixeira et al. 2018), but also a consequence of recent expansion (Mas-Peinado et al. 2015). Distinguishing between these two situations is highly relevant when evaluating the conservation status of a given species (Hampe and Petit 2005).