THE CARABIDAE (INSECTA: COLEOPTERA) OF THE UPPER SALIENTES VALLEY (LEÓN, NORTHERN SPAIN): FAUNA, CHOROLOGY, AND TAXONOMIC NOTES

Introduction[Up]

Almost two centuries have passed since the first Iberian catalogues of Carabidae were made (‍Rambur, 1837-‍1838; ‍Cardona y Orfila, 1872; ‍Pantel, 1888; ‍Champion, 1898; among others) and, since then, the faunistic and chorological knowledge of this family of Coleoptera has increased substantially. The first global vision of carabidological knowledge in Spain is due to Graells (‍1858), and in Portugal to Putzeys (‍1874) and Paulino de Oliveira (‍1894). Later, De la Fuente (‍1918-1921) provided the first annotated catalogue on the Carabidae of Spain and, years later, elaborated identification keys for the Peninsular cincindelids and carabids known to date (‍De la Fuente, 1927). Although many entomologists continued to provide data on Iberian Carabidae, it is fair to recognize the decisive contribution of Claude Jeanne who, with his multiple explorations in Spain and Portugal, greatly expanded the knowledge of this group of beetles up to the present (‍Tamisier, 2017). He expanded the chorological records of numerous species, cited many others for the first time in the Iberian Peninsula,and described a high number of new taxa, most of them endemic to this territory. The synthesis of a large part of the results of his work was recorded in an Iberian catalogue (‍Jeanne & Zaballos, 1986) that was a reference for any study on Iberian carabids. This catalogue was followed by others in a dynamic of taxonomic and chorological expansion, as well as a systematic update (‍Zaballos & Jeanne, 1994; ‍Serrano, 2003, ‍2013), including synthetic electronic versions with a different approach to the previous ones (‍Serrano, 2020). In this context, studies on carabid fauna from large peninsular regions were also carried out (‍Herrera & Arricibita, 1990; ‍Ortuño & Toribio, 1996; ‍Ortuño & Marcos, 2003; ‍Campos & Novoa, 2006; ‍Aguiar & Serrano, 2013; ‍López-Pérez et al., 2014; ‍Toribio & Ramos-Abuín, 2018; ‍Serrano et al., 2021; among others), mountainous areas (‍Mateu & Colás, 1954; ‍Novoa, 1975, ‍1979; ‍Palanca, 1980; ‍Gimeno, 1984; ‍Zaballos, 1984, ‍1994; ‍Alonso et al., 1987; ‍Arribas, 1994; ‍Andújar et al., 2000; ‍Ruiz Tapiador & Zaballos, 2001, among others) and various natural spaces such as wetlands and hydrographic basins (‍Vives & Vives, 1978, ‍1986; ‍Serrano, 1983; ‍Cárdenas, 1985; ‍Zaballos, 1986; ‍Ortiz et al., 1989; ‍Serrano et al., 1990; ‍Vázquez et al., 1991; ‍Ortuño & Marcos, 1997; ‍Andújar et al., 2001; ‍Ortuño et al., 2004; among others), thus contributing to broaden the faunistic knowledge of the Iberian Carabidae, and enriching the catalogues that followed.

This study falls in line with the faunistic works already mentioned in its goal to offer the most complete set of data possible on an area of special interest, potentially revealing aspects of the uniqueness of the enclave and thus adding relevant knowledge to the Iberian carabid fauna. In this context, he Salientes Valley and its surrounding mountains, offer an especially interesting study area due to a combination of the influence of the nearby Cantabrian Mountains paired with an ongoing process of geographical isolation, especially since the Pliocene. The limited connection and disconnection of the free pass with the northern Cantabrian reliefs is closely linked to the recent history of the Sil River. The ascending erosion of this river has been carving the upper basin of the Luna River and changing the crossing point (from west to east) between both zones: initially (Pliocene) at about 1,600 m between Cueto del Oso (1,904 m) and Cuerno (1,932 m), and currently far to the east, around Puente de las Palomas (1,220 m) (‍García de Celis, 1997; ‍Alfonso-Gómez 2003). This circumstance makes this valley an area of great interest, especially due to its colonization by species from the Cantabrian range corridor. The relative isolation from the Cantabrian Mountains means that its biota, although related, differs notably. A non-trivial example is the absence of the beech (Fagus sylvatica L.) and an important cohort of accompanying species. Being further south of the Cantabrian Mountains and sheltered from oceanic influence, the climate is much sunnier and more continental, which means drier weather and more extreme temperatures (‍Walker, 2002). On the other hand, the Salientes Valley is a remote area, far from the travelling paths of the entomologists who studied the Cantabrian carabid fauna in the 19^th and 20^th centuries, and therefore, like much of the north of the Montes de León, is still a very poorly known place.

With this study it is expected to expand the faunistic knowledge of this remote valley, contributing for the first time to this area an extensive list of Carabidae species. At the same time it is expected to identify some of its faunal singularities dictated by the presence or absence of certain taxa.

Material and methods[Up]

This study is based on four entomological sampling campaigns carried out during three consecutive years: 1^st campaign (06, 07, 08, 09, 10, 11-VIII-2019); 2^nd campaign (04, 05, 06, 07, 08-VIII-2020); 3^rd campaign (24, 25, 26, 27, 28, 29-VI-2021) and 4^th campaign (29, 30, 31-VII-2021, 01, 02, 03-VIII-2021). Campaign involvement was as follows: first, second and fourth campaigns: V.M. Ortuño & O. Arribas leg.; third: V.M. Ortuño & E. Andrés leg. Sampling was done by active capture, by pitfall traps baited with vinegar, and by sifting leaf litter and soil with Winkler devices. 61 localities were sampled (Table 1) covering a large part of the upper Salientes Valley and its surrounding mountains (Fig. 1). All collected specimens were prepared following entomological protocols and are kept in the VMO-UAH collection (Vicente M. Ortuño, Department of Life Sciences of Alcalá University, Madrid, Spain) except the Carabinae, which are kept in the Oscar Arribas collection (Soria, Spain). In most species, male identification was completed by studying the aedeagus, which in some cases were included in DMHF (dimethyl hydantoin formaldehyde) resin on transparent acetate sheets.

The taxonomic and nomenclatural criteria used are those included in the latest Iberian Carabidae catalogues (see ‍Serrano, 2013, ‍2020) with few modifications, and biogeographical analysis is carried out by assigning the same chorological types that appear in the last one (‍Serrano, 2020). A specimen of Microlestes Schmidt-Goebel, 1846 could not be identified to a specific level, so it was not possible to assign it a biogeographical category. In this work, we include the Cicindelidae as a subfamily of the Carabidae, although the last Iberian catalogue (‍Serrano, 2020) treats this group as a family close to Carabidae (following ‍Duran & Gough, 2020). For Carabus nomenclature we follow the latest Deuve monograph (‍2021).

The study area is located in an intermediate alignment between the main Cordillera Cantábrica and south of Montes de Leon: 42º53’ to 43º01’. The most conspicuous peaks are Nevadín (2,082 m), Tambarón (2,102 m), Catoute (2,111 m) and Valdiglesias (2,136 m). They are among the most extensive and complex orographic assemblages of the Cordillera (‍García de Celis, 1997).

This area is constituted by palaeozoic materials of the Asturoccidental Leonesa Zone, one of the great units in which the Iberian Hercynian Massif is divided. The oldest strata (Precambrian) are from the Villalba Serie (very friable slates –from Nevadín, Puerto del Portillín, etc.–); Lower Cambrian rocks are grouped in the Cándama Formation (microconglomerates, sandstones, slates, and white tabled quartzites –Tambarón, Molar–). Above is the Fm. Vegadeo (marbles, marbled limestones, and solid dolomites very narrow ditches in the Tambarón area) from the Middle Cambrian. And on top of both is the Los Cabos Series (white quartzites alternated with sandstones and quartzites) from the Upper Cambrian to Lower Ordovician (Valdiglesias, Robeza, Catoute, Arcos del Agua, Suspirón). Finally, above all of them is the Luarca Series with solid black slates from the Middle Ordovician (‍Matas, 1982). Hercynian Orogeny followed by Alpine Orogeny folded the area mainly with NW-SE and NE-SW faults, uplifting these mountain ranges from surrounding areas such as the Bierzo graben. The last touches to the area were due to Quaternary glaciation. During the Upper Pleistocene, most of the valleys housed glacial tongues below 900 m a.s.l. (‍García de Celis, 1997).

Unexpectedly by its distance to the main Cantabrian Range, very extensive glaciers developed in this area due to the combination of abundant precipitation coming from the Atlantic Ocean and increasingly colder (more continental) conditions. Glaciers appeared on all the northern slopes of mountains surrounding Salientes and Salentinos valleys: the northern slopes of Nevadín (Sª del Coto), Tambarón, and to the West (peñas del Lago and Valdiglesias), and also in Catoute. Usually, glacier apparatuses in this area were more developed in valleys oriented to the East (as opposed to the Castilian Meseta, colder and with greater persistence of snow), while those oriented to the West had almost no glacier modelling. Salientes and Salentinos valleys were an exception, with glacier cirques on the highest parts of northern slopes that descend to 1,400 m a.s.l. in some places. Postglacier thaw in the area (Laguna de Villaseca, Laciana) has been dated from 34,000±1,400 years before the present (‍Jalut et al., 2004). The peaks were converted into “horns” by glacier erosion, whereas their connecting spurs still preserve rounded and extensive forms, locally called “lombos”. They were a few kilometers long and were located above 1,800 m, marking the paleoreliefs of the area. Around 1,500-1,600 m, another group of plains is on the middle slope. A third and final group of plain formsappears 200 m above the bottom of the valley.

Climate (and therefore the vegetation) is deeply conditioned by oceanic influence, as in other NW Iberian areas. This oceanic influence gradient in the case of Salientes Valley, from the upper valley (moister) to its lower parts (with increasing Mediterranean influence). Climate is Temperate-Humid in Koppen classification with 1,000–1,400 mm of average annual precipitation, 15–20 snowfall days per year, and an average temperature of 7.5º–10ºC. Detailed climate data can be found in IGN (‍1992) and Ninyerola et al. (‍2005). In general, this area is sunnier than the main Cordillera Cantábrica and it is generally well known that these mountains frequently offer sunshine when it rains or is cloudy in the main Cordillera Cantábrica (‍Walker, 2002; ‍Álvarez-Ruiz, 2011).

From a biogeographic perspective, the study area is located inside the Eurosiberian Region, specifically in the Orocantabric Province and the Laciano-Ancarense Sector (‍Rivas-Martínez, 1987). Pyrenean oak forests grow on acid substrates of the south-facing slopes of the Montane belt, whereas deciduous forests are better represented on the northern, generally wetter slopes (‍Blanco et al., 2005). Pyrenean oak forests are formed by Quercus pyrenaica Willd. frequently accompanied by holly (Ilex aquifolium L.), birch (Betula alba L.), hazel (Corylus avellana L.), ash (Fraxinus excelsior L.), and wild cherry (Prunus avium L.). These sub-humid forests comprise the Orocantabrian and Galician-Asturian mountain acidophilic series of Pyrenean oak: Linario triornithophorae-Querceto pyrenaicae sigmetum (‍Rivas-Martínez, 1987). The original structure of the forest has been lost by successive fellings and burning resulting in a sparse appearance, but with a highly developed understory (‍Blanco et al., 2005). Mixed forests are mainly composed of birch (Betula alba L.) with some sessile oaks (Quercus petraea (Mattuschka) Liebl.), holly(I. aquifolium L.) and maples (Acer pseudoplatanus L.). They are part of the acidophilic orocantabrian highland series of birch: Luzulo heriquesii-Betuleto celtibericae sigmetum (‍Rivas Martínez, 1987). Currently, birch trees are being regenerated due to their pioneering colonizing nature and a lower incidence of agricultural pressure (‍García de Celis et al., 2004). Valseco River valley presents a riverside forest formed by different species of Salix close to the shore. In a second strip, there are poplars (Populus nigra L.), ash (F. excelsior L.), and elms (Ulmus glabra Huds.). In the nearby areas of Salientes village, the riparian forest is altered due to its transformation into cultivation areas and cattle meadows (‍Ferreras & Arozena, 1987). On the Subalpine belt (above 1,800 m) dwarf junipers appear that belong to the subalpine orocantabric series of Juniperus nana (Junipero nanae-Vaccinieto uliginosi sigmetum). Along with J. nana, there are two species of blueberry, Vaccinium myrtillus L. and Vaccinium uliginosum L. (‍Rivas-Martínez, 1987) which constitute a nutritionalresource for the associated fauna. Around the top of Pico Valdiglesias (2,136 m) we find pastures of Festuca eskia DC., Agrostis tileni Nieto Fel. & Castrov., Luzula caespitosa Gay and other herbaceous plants adapted to strong winds and frosts, while wetter areas support Nardus stricta L. (‍Rivas-Martínez, 1987). It should also be mentioned that the scree vegetation is mainly composed of Cryptogramma crispa (L.) R. Br., Ranunculus parnassiifolius L. Rothm., and Spergula viscosa Lag. (‍Rivas-Martínez, 1987). Sphagnum peat bogs are also common in this area (‍Fernández-Prieto et al., 1987).

Results[Up]

Abundance and taxonomic representation

A total of 1,255 specimens were studied (Fig. 2), the majority, 85%, attributable to one of these two subfamilies: Harpalinae (54%) and Trechinae (31%). The tribes that contributed the most specimens to the Harpalinae samples were Pterostichini (200 exx, 30%), Harpalini (167 exx, 25%), and Sphodrini (150 exx, 22%). In a second-order of importance were Platynini (83 exx, 12%) and Zabrini (55 exx, 8%), and there was also a very small representation of Lebiini, Licinini, Chlaeniini, and Masoreini. The Trechinae are abundantly represented by the tribes Bembidiini (242 exx, 63%) and Trechini (137 exx, 36%), whereas the Tachyini were minimally represented by only one not very abundant species. The Nebriinae represented 12% of all collected carabids, with an unequal representation of the tribes Nebriini (139 exx, 93% of the subfamily) and Notiophilini (11 exx, 7%). The subfamily Carabinae subfamily, with only 3% of the total carabids, was more abundantly represented by the tribe Carabini (79% of Carabinae) than by the Cychrini (21%). Finally, a very low number of specimens belonging to three other subfamilies were recorded, these being the Cicindelinae, Elaphrinae, and Scaritinae.

The taxonomic analysis revealed 101 species with an observed diversity unequally distributed among 7 subfamilies and 19 tribes (Fig. 3). As was the case with the abundance analysis, Harpalinae and Trechinae were also the subfamilies with the greatest diversity of species in the Salientes carabid fauna: 61%, and 23%, respectively. Among the Harpalinae, the Harpalini (18 spp, or 29% of the total subfamily), Zabrini (11 spp, 18%), Pterostichini (10 spp, 16%) and Sphodrini (9 spp, 14%) tribes contributed the highest specific diversity, followed by Platynini (6 spp, 10%) and Lebiini (5 spp, 8%), and finally only one species in Licinini, Chlaeniini, and Masoreini. The Trechinae held a better representation of the Bembidiini tribe (17 spp, 74% of total), than of the Trechini (5 spp, 22%) and the anecdotal Tachyini (1 sp, 4%) poorly represented. Carabinae was the third subfamily in order of contributed diversity (7% of total carabids; with representatives of the Carabini (6 spp, 86% of the subfamily) and the Cychrini (1 sp, 14%). The subfamily Nebriinae contributed 6% of all carabids. The tribes Nebriini (4 spp, 67% of the total subfamily) and Notiophilini (2 spp, 33%) are included in this group. Three other subfamilies (Cicindelinae, Elaphrinae, and Scaritinae) with their respective tribes were barely represented by single species and very low specimen counts.

Faunistic list

This section lists all the species collected in this study indicating the sampling locations in an abbreviated form (letter/s that correspond to Table 1 and Fig. 1). For each locality, the number of specimens of each sex and the date of collection is recorded. To shorten this section we have omitted collector names, although the information can be derived from the capture dates (see material and methods). Brief comments regarding habitat are also included. A biogeographic category (biogeographical element) has been assigned to each species in order to allow a biogeographical approximation to the Carabidae of Salientes.

Cicindela (Cicindela) campestris campestris Linnaeus, 1758

G: 1 ♀, 07-VIII-2020. K: 1 ♀, 25-VI-2021. AD: 2 ♂♂, 27-VI-2021. This species was observed on forest tracks and montane meadows between 1,350 and 1,590 m a.s.l. WPAL element.

Calosoma (Calosoma) sycophanta (Linnaeus, 1758)

U: 1 ex., 29-VI-2021. An elytron was found on a forest track at 1,240 m a.s.l. WPAL element.

Carabus (Archicarabus) nemoralis lamadridae Born, 1895

P: 1 ♂, 04-VIII-2020; 1 ♀, 04-VIII-2020/08-VIII-2020; 1 ♂, 25-VI-2021. Epiedaphic and sublapidicolous specimens were collected on a forest path with elm, maple and ash trees at a low altitude (1,261 m a.s.l.). ENDE element.

Carabus (Chrysocarabus) lineatus lateralis Chevrolat, 1840.

F: 1 ♂, 07-VIII-2020. P: 1 ♀, 07-VIII-2019; 1 ♀, 04-VIII-2020/08-VIII-2020. S: 1 ♀, 04-VIII-2020/08-VIII-2020. AB: 1 ♂, 06-VIII-2020. AE: 1 ♂, 1 ♀, 06-VIII-2020. AY: 1 ♂, 04-VIII-2020/08-VIII-2020. BD: 1 ♂, 26-VI-2021. BG: 1 ♂, 26-VI-2021. BH: 1 ♀, 26-VI-2021. This species is widely distributed in the valley, wooded slopes and montane meadows. It shows a predilection for nemoral environments although it is not abundant. It was observed in an altitude range of 1,218 to 1,804 m a.s.l. ENDE element.

Carabus (Mesocarabus) macrocephalus macrocephalus Dejean, 1826

W: 1 ♀, 01-VIII-2021. AF: 1 ♀, 02-VIII-2021. AK: 4 ♂♂, 02-VIII-2021. This sublapidicolous species was found in forest clearings (Pyrenean oak) and montane meadows located at medium and high altitudes (1,390 to 1,970 m a.s.l.). ENDE element.

The specimens of C. (M.) macrocephalus from the area are, without a doubt, similar to those from the axis of the Cantabrian Mountains (ssp. macrocephalus Dejean, 1826 or ssp. joaquini Breuning & De Toulgoët, 1974). Of the plethora of named forms, the closest is magdalenai Meyer & Mollard, 1996 (“magdalenei”, sic.! in ‍Mollard, 2013) (described as intermediate between moroderi and asturicus) (typical locality: Puerto de la Magdalena), in the adjoining valley to the N of this study area. However, this form is not always recognized, and some authors assimilate it to moroderi (typical locality: Montes de León, sic) (eg. ‍Toulgoët & Lassalle, 1983; ‍Mollard, 2013), whose morphology is more similar to “lusitanicus”. The moroderi forms, considered transitional between lusitanicus and macrocephalus by some authors, inhabit Montes de León (particularly south of Puerto del Manzanal: Teleno, Trevinca, Sanabria, etc..., although also to the north with the border in the Sil and Luna rivers, according to Toulgoët & Lassalle, 1983, for whom magdalenai with its longer elytra would be transitional between moroderi -alreadytransitional- and macrocephalus) and, therefore, quite different from the Mesocarabus Thomson, 1875 of the Salientes Valley, that are indistinguishable from those of the nearby Cantabrian axis. Another form described from a more northerly valley (note the “fine grain” of the nomenclature among “carabophiles”) is “joaquini” Breuning & De Toulgoët, 1974 (“joacquini”, sic! in ‍Mollard, 2013) (typical locality: near Torrebarrio, León), with a “macrocephalus” morphology (although it was described as subspecies of lusitanicus when treating both species as only one), already located in the axis of the Cantabrian Mountains, and to which we can attribute, without major problems, the collected specimens (if not best directly to macrocephalus Dejean, 1826, a more widespread taxon).

Carabus (Oreocarabus) luetgensi getschmanni Lapouge, 1924

O: 1 ♂, 2 ♀♀, 04-VIII-2020/08-VIII-2020. AP: 3 ♀♀, 31-VII-2021. This species was observed in ditches and forest path litter with maple and hazel at low and medium altitudes (1,233 to 1,440 m a.s.l.), Sublapidicolous behaviour. ENDE element.

Carabus (Rhabdotocarabus) melancholicus costatus Germar, 1824

AA: 1 ♂, 27-VI-2021. AC: 1 ♂, 1 ♀, 06-VIII-2020. Strongly hygrophilous species that was only found under stones next to puddles in a ruderal environment between 1,440-1,560 a.s.l. ENDE element.

Cychrus spinicollis Dufour, 1820

H: 1 ♂, 07-VIII-2019. K: 1 ♀, 30-VII-2021. M: 2 ♀♀, 28-VI-2021; 1 ♀, 03-VIII-2021. AQ: 1 ♂, 1 ♀, 08-VIII-2019. BB: 1 ♀, 26-VI-2021. Observed under stones in a wet birch forest, riparian forest and hedgerows, at low and medium altitudes (1,230-1,458 m a.s.l.). ENDE element.

Leistus (Leistus) barnevillei Chaudoir, 1867

H: 1 ♀, 07-VIII-2020. K: 1 ♂, 25-VI-2021; 1 ♀, 30-VII-2021. AH: 11 ♂♂, 02-VIII-2021. AI: 18 ♂♂, 02-VIII-2021. AO: 1 ♂, 10 ♀♀, 10-VIII-2019. AQ: 1 ♂, 1 ♀, 08-VIII-2019; 1 ♂, 1 ♀, 09-VIII-2019; 4 ♂♂, 31-VII-2021. BA: 1 ♂, 28-VI-2021. BB: 1 ♀, 26-VI-2021. BC: 4 ♀♀, 06-VIII-2019. BD: 1 ♂, 06-VIII-2019. It was collected in a wide altitude range (1,290-1,835 m a.s.l.) closely linked to the edaphic and endogean environment in wooded areas (mixed forest dominated by birch) and mountain scrub. It is often part of the sublapidicolous communities. ENDE element.

Nebria (Eunebria) jockischii orensis Breit, 1914

F: 1 ♂, 3 ♀♀, 07-VIII-2020. I: 8 ♂♂, 4 ♀♀, 07-VIII-2019. J: 1 ♂, 07-VIII-2020. K: 1 ♀, 25-VI-2021. Q: 1 ♂, 04-VIII-2020. Z: 3 ♂♂, 2 ♀♀, 09-VIII-2019. AO: 4 ♂♂, 5 ♀♀, 10-VIII-2019. BB: 1 ♂, 04-VIII-2020. BF: 1 ♂, 1 ♀, 05-VIII-2020. This riparian species was observed in almost the entire fluvial network area, from the bottom of the valley (1,183 m a.s.l.) to mid-altitudes of lateral valleys (1,350-1,546 m a.s.l.). ENDE element.

Nebria (Nebria) asturiensis Bruneau de Miré, 1964

AF: 1 ♀, 02-VIII-2021. AG: 1 ♂, 2 ♀♀, 06-VIII-2020. AH: 8 ♂♂, 5 ♀♀, 02-VIII.2021. AI: 1 ♂, 2 ♀♀, 02-VIII-2021. BG: 1 ♂, 1 ♀, 26-VI-2021. It seems to be absent in the valley forest, but was found under stones and buried in the ground in supraforestal areas (1,654-1,835 m a.s.l.) dominated by broom and heather. ENDE element.

Nebria (Nebria) brevicollis (Fabricius, 1792)

C: 2 ♂♂, 3 ♀♀, 30-VII-2021. K: 1 ♂, 3 ♀♀, 25-VI-2021. Q: 2 ♀♀, 04-VIII-2020. AB: 1 ♀, 02-VIII-2021. AU: 1 ♂, 1 ♀, 25-VI-2021/29-VI-2021. AW: 5 ♀♀, 25-VI-2021; 1 ♂, 2 ♀♀, 29-VII-2021. BA: 1 ♂, 28-VI-2021. Hygrophilous species that was found on riversides, forest environments, bogs, and wet meadows between 1,183-1,530 m a.s.l. EURP element.

Notiophilus biguttatus (Fabricius, 1779)

H: 1 ♀, 07-VIII-2019. J: 1 ♂, 07-VIII-2020. AM: 1 ♂, 31-VII-2021. At medium altitude (1,382-1,573 m a.s.l.) in fallen leaves of riverside and under stones of ruderal environments. PALE element.

Notiophilus rufipes Curtis, 1829

K: 1 ♀, 25-VI-2021. M: 1 ♀, 03-VIII-2021. W: 2 ♀♀, 06-VIII-2020; 1 ♀, 27-VI-2021. AQ: 1 ♀, 08-VIII-2019; 1 ♀, 09-VIII-2019. AW: 1 ♀, 29-VII-2021. These specimens were found among fallen leaves on wet soil and under track stones at low and medium altitudes (1,230-1,432 m a.s.l.). SOER element.

Elaphrus (Neoelaphrus) pyrenoeus Motschulsky, 1850

F: 1 ♂, 1 ♀, 07-VIII-2020. It was found on a bog next to the riverside environment at 1,472 m a.s.l. ENDE element.

Clivina (Clivina) fossor (Linnaeus, 1758)

AW: 1 ♂, 25-VI-2021. This specimen was collected under a stone on flooded soil on a path at 1,260 m a.s.l. HOLA element.

Trechus (Trechus) fulvus Dejean, 1831

H: 1 ♀, 11-VIII-2019. AM: 1 ♀, 31-VII-2021. AO: 1 ♀, 10-VIII-2019. AP: 1 ♂, 31-VII-2021. AQ: 5 ♂♂, 1 ♀, 08-VIII-2019; 2 ♂♂, 09-VIII-2019; 2 ♂♂, 31-VII-2021. BB: 2 ♂♂, 04-VIII-2020. BD: 1 ♂, 1 ♀, 06-VIII-2019. Hygrophilous, lucifugal, and geophilic species. It was found in various localities under stones, and in soil/subsoil micro spaces of streams and valleys without surface circulating water, or among the leaf litter of gallery forest at low and medium altitudes (1,356-1,573 m a.s.l.). WEUR element.

In this study, the specimens of T. fulvus are not assigned to any subspecies following the taxonomic criteria established by Ortuño et al. (‍2017) who affirm based exclusively on morphological characters that it is difficult to defend the validity of the subspecies described for Iberian populations of this species. Therefore, the biogeographic category assigned to it corresponds to its species level.

Trechus (Trechus) gallaecus Jeannel, 1921 (Figs. 4a, 5–6)

H: 2 ♂♂, 3 ♀♀, 07-VIII-2019; 1 ♂, 11-VIII-2019; 2 ♂♂, 1 ♀, 07-VIII-2020. AO: 8 ♂♂, 2 ♀♀, 10-VIII-2019. AQ: 4 ♂♂, 7 ♀♀, 08-VIII-2019; 1 ♂, 1 ♀, 09-VIII-2019. AT: 1 ♂, 10-VIII-2019. AY: 1 ♀, 04-VIII-2020/08-VIII-2020. BA: 1 ♂, 28-VI-2021. BC: 1 ♂, 1 ♀, 06-VIII-2019. BG: 1 ♀, 05-VIII-2020. Forest species was located in various places between 1,258-1,654 m a.s.l., especially among the humid leaf litter of birch, hazel, maple, willow and rowan forests, and in soil/subsoil interstices. ENDE element.

Trechus (Trechus) obtusus Erichson, 1837

B: 1 ♂, 30-VII-2021. J: 1 ♂, 07-VIII-2020. M: 2 ♀♀, 03-VIII-2021. W: 1 ♀, 06-VIII-2020; 2 ♂♂, 2 ♀♀, 27-VI-2021; 1 ♂, 2 ♀♀, 01-VIII-2021. X: 2 ♀♀, 01-VIII-2021. AB: 1 ♂, 06-VIII-2020. AP: 3 ♂♂, 4 ♀♀, 31-VII-2021. AX: 1 ♀, 06-VIII-2020. It was observed under stones of ruderal environments, bogs, and soils with leaf litter (especially of mesothermal vegetation) in localities located at mid-low altitudes (1,230-1,617 m a.s.l.).EUME element.

Trechus (Trechus) suturalis Putzeys, 1870 (Figs. 4b, 7)

E: 1 ♂, 2 ♀♀, 07-VIII-2020. H: 4 ♂♂, 5 ♀♀, 11-VIII-2019; 2 ♂♂, 07-VIII-2019; 7 ♂♂, 07-VIII-2020. L: 1 ♀, 25-VI-2021/29-VI-2021. AB: 1 ♀, 06-VIII-2020. AM: 1 ♀, 31-VII-2021. AO: 3 ♂♂, 2 ♀♀, 10-VIII-2019. AP: 1 ♂, 31-VII-2021. AQ: 11 ♂♂, 5 ♀♀, 08-VIII-2019; 2 ♂♂, 2 ♀♀, 09-VIII-2019; 1 ♂, 31-VII-2021. AY: 1 ♀, 04-VIII-2020/08-VIII-2020. Forest species located in several places at low and medium altitudes (1,258-1,573 m a.s.l.) that appear syntopic with T. gallaecus. It was observed among deciduous forests with moist leaf litter (birch, hazel, maple, willow, rowan) and in soil/subsoil interstices. ENDE element.

Trechus (Trechus) teverganus Toribio, 2015 (Fig. 4c)

AQ: 1 ♂, 1 ♀, 08-VIII-2019; 1 ♂, 1 ♀, 09-VIII-2019. BC: 1 ♀, 06-VIII-2019. BE: 1 ♂, 06-VIII-2019. Species located at medium altitude (1,424-1,514 m a.s.l.) in the subterranean environment of humid places, valleys, and near streams without surface water activity, associated to birch forest. ENDE element.

Tachyura (Tachyura) parvula (Dejean, 1831)

K: 1 ♀, 25-VI-2021. AD: 2 ♀♀, 06-VIII-2020; 2 ♀♀, 27-VI-2021. Hygrophilous species that was barely observed on the sunny edge of streams located at medium altitude (1,350-1,590 m a.s.l.). EUME element.

Ocys (Ocys) tachysoides (Antoine, 1933)

H: 2 ♀♀, 07-VIII-2019. A hygrophilous species that was found only among the leaf litter of riparian birch forest in a shady environment (1,458 m a.s.l.). IBMG element.

Sinechostictus (Sinechostictus) stomoides (Dejean, 1831)

F: 1 ♂, 3 ♀♀, 07-VIII-2020. H: 1 ♀, 07-VIII-2019; 4 ♂♂, 1 ♀, 11-VIII-2019. K: 2 ♀♀, 25-VI-2021. T: 1 ♂, 04-VIII-2020. Z: 1 ♀, 09-VIII-2019. AW: 1 ♂, 24-VI-2021. Strongly hygrophilous species that was usually found under stones on the banks of streams that cross the riparian forest. At low and medium altitudes (1,240-1,472 m a.s.l.). EURP element.

Bembidion (Emphanes) minimum (Fabricius, 1792)

AD: 1 ♂, 27-VI-2021. Riparian species which the only specimen was observed at 1,590 m a.s.l. on the sunny edges of a stream. SIER element.

Bembidion (Trepanes) articulatum (Panzer, 1796)

AD: 1 ♂, 1 ♀, 27-VI-2021. Hygrophilous species, frequently riparian, that was occasionally observed at 1,590 m a.s.l. on sunny stream banks. ASER element.

Bembidion (Philochthus) guadarramense Gautier des Cottes, 1866

E: 1 ♀, 07-VIII-2020. AB: 1 ♀, 06-VIII-2020. BI: 6 ♂♂, 7 ♀♀, 05-VIII-2020. Hygrophilous species settled on riversides and marshy areas between 1,479 and 1,825 m a.s.l. It has been observed abundantly in hygroturbose substrates near Pico Valdiglesias. ENDE element.

Bembidion (Philochthus) guttula (Fabricius, 1792)

F: 1 ♂, 07-VIII-2020. J: 1 ♀, 07-VIII-2020. K: 9 ♂♂, 3 ♀♀, 25-VI-2021. M: 1 ♀, 28-VI-2021. W: 1 ♀, 27-VI-2021. AD: 1 ♂, 27-VI-2021. AV: 1 ♀, 04-VIII-2020/08-VIII-2020. Hygrophilous species frequently develops sublapidicolous behaviour in riparian environments or moist grassland. Observed at low and medium altitude localities (1,230-1,590 m a.s.l.). WPAL element.

Bembidion (Bembidion) quadrimaculatum (Linnaeus, 1761)

AD: 1 ♂, 06-VIII-2020; 1 ♀, 27-VI-2021. Hygrophilous species, frequently riparian, was occasionally observed on the sunny edge of a stream at 1,590 m a.s.l. HOLA element.

Bembidion (Nepha) callosum subconnexum De Monte, 1953

F: 1 ♀, 07-VIII-2020. K: 1 ♂, 25-VI-2021. Q: 9 ♂♂, 2 ♀♀, 04-VIII-2020. AB: 2 ♀♀, 06-VIII-2020. AO: 1 ♂, 10-VIII-2019. BB: 1 ♂, 04-VIII-2020. BF: 2 ♀♀, 05-VIII-2020. BH: 1 ♀, 26-VI-2021. Hygrophilous and riparian species widely distributed throughout the riverside localities of the sampled area. It dwells among riverside gravel, under boulders, and even buried on temporarily inactive river courses. It has been observed at very different altitudes, from the bottom of the valley to the middle and upper slopes (1,183-1,804 m a.s.l.). ENDE element.

Bembidion (Nepha) ibericum Piochard de la Brûlerie, 1867

A: 13 ♂♂, 14 ♀♀, 30-VII-2021. F: 5 ♂♂, 6 ♀♀, 07-VIII-2020. J: 1 ♀, 07-VIII-2020. K: 1 ♂, 25-VI-2021. Z: 1 ♂, 09-VIII-2019. AB: 5 ♀♀, 06-VIII-2020. AD: 1 ♂, 2 ♀♀, 27-VI-2021. BB: 1 ♂, 04-VIII-2020. BE: 1 ♀, 05-VIII-2020. BF: 1 ♀, 05-VIII-2020. Hygrophilous and frequently riparian species, although can seek refuge under stones on humid soils (path ditches, forest clearings, etc.), or even be buried in temporarily inactive fluvial courses. Observed at low and medium altitudes (1,350-1,673 m a.s.l.). ENDE element.

Bembidion (Omoperyphus) strictum (Schuler, 1962)

A: 1 ♂, 1 ♀, 30-VII-2021. F: 1 ♂, 1 ♀, 07-VIII-2020. AB: 1 ♀, 06-VIII-2020. BF: 2 ♂♂, 3 ♀♀, 05-VIII-2020. Hygrophilous species that wanders among rivers gravel, sheltering under stones on moist soil near the riverbeds, and even buried in the soil of riverside slopes. It was observed between 1,472-1,673 m a.s.l. ENDE element.

Bembidion (Peryphanes) deletum schulerianum Müller-Motzfeld, 1986

K: 2 ♂♂, 2 ♀♀, 29-VI-2021; 1 ♀, 30-VII-2021. AB: 2 ♂♂, 1 ♀, 06-VIII-2020. AM: 2 ♂♂, 31-VII-2021. BA: 1 ♂, 28-VI-2021. Although it is a hygrophilous species, it cannot be considered typically riparian. It is often buried in forest soils rich in organic debris. It was observed at low and medium altitudes (1,290-1,573 m a.s.l.). WEUR element.

Bembidion (Bembidionetolitzkya) geniculatum geniculatum Heer, 1837

H: 1 ♂, 07-VIII-2019. I: 1 ♀, 30-VII-2021. Z: 1 ♀, 09-VIII-2019. AO: 1 ♀, 10-VIII-2019. BB: 1 ♂, 2 ♀♀, 04-VIII-2020. Riparian species that tends to settle on gravel river beaches and boulders located at low and medium altitudes (1,356-1,458 m a.s.l.). ALPI element.

Bembidion (Bembidionetolitzkya) leonense Jeanne & Muller-Motzfeld, 1982

AO: 1 ♀,10-VIII-2019. Uncommon riparian species dwells on fluvial areas of the bottom of the valley. The specimen studied was found under a stone on Arroyo de Terrafracio edge, at 1,356 m a.s.l. ENDE element.

Bembidion (Bembidionetolitzkya) tibiale (Duftschmid, 1812)

F: 1 ♂, 2 ♀♀, 07-VIII-2020. H: 1 ♀, 07-VIII-2019. I: 1 ♀, 30-VII-2021. Q: 4 ♂♂, 3 ♀♀, 04-VIII-2020. Z: 3 ♂♂, 1 ♀, 09-VIII-2019. AO: 4 ♂♂, 1 ♀, 10-VIII-2019. BB: 1 ♂, 4 ♀♀, 04-VIII-2020. Riparian species that grows on small river beaches composed of gravel and boulders. It was observed between 1,183-1,472 m a.s.l. EURP element.

Bembidion (Peryphus) tetracolum Say, 1823

K: 4 ♀♀, 25-VI-2021. AR: 2 ♀♀, 10-VIII-2019. AW: 6 ♂♂, 1 ♀, 24-VI-2021; 3 ♂♂, 25-VI-2021. Hygrophilous species can be found in different humid substrates (riversides, moss pads, wet ditches, etc.) at low altitudes (1,260-1,350 m a.s.l.). HOLA element.

Bembidion (Metallina) lampros (Herbst, 1784)

B: 4 ♀♀, 30-VII-2021. F: 1 ♂, 5 ♀♀, 07-VIII-2020. K: 1 ♂, 25-VI-2021. M: 1 ♀, 28-VI-2021. W: 1 ♂, 2 ♀♀, 27-VI-2021. AD: 5 ♂♂, 2 ♀♀, 06-VIII-2020; 6 ♀♀, 27-VI-2021. AF: 1 ♂, 02-VIII-2021. AG: 1 ♂, 06-VIII-2020. AW: 1 ♂, 24-VI-2021; 2 ♂♂, 3 ♀♀, 25-VI-2021; 2 ♂♂, 1 ♀, 29-VII-2021. BA: 1 ♂, 28-VI-2021. BI: 1 ♀, 05-VIII-2020. It usually runs at daylight in open and sunny areas (meadows, roadside ditches, forest clearings) although it also takes refuge under stones. It was collected at very different altitudes from the bottom of the valley to the tops of mountain crests (1,230-1,825 m a.s.l.). PALE element.

Bembidion (Metallina) properans (Stephens, 1828)

C: 1 ♂, 30-VII-2021. F: 2 ♂♂, 07-VIII-2020. A less common species than B. (M.) lampros in the valley, although it shows similar behaviour and habitat selection. It was observed at mid-altitude (1,472-1,525 m a.s.l.). ASER element.

Cryobius cantabricus cantabricus (Schaufuss, 1862)

D: 2 ♂♂, 07-VIII-2019. E: 1 ♂, 07-VIII-2020. H: 2 ♀♀, 11-VIII-2019; 1 ♂, 07-VIII-2020. J: 1 ♂, 3 ♀♀, 07-VIII-2020. K: 1 ♂, 3 ♀♀, 25-VI-2021; 1 ♀, 30-VII-2021. Z: 1 ♂, 09-VIII-2019. AH: 1 ♂, 02-VIII-2021. AJ: 1 ♂, 1 ♀, 02-VIII-2021. AK: 1 ♂, 02-VIII-2021. AO: 1 ♂, 10-VIII-2019. AP: 4 ♂♂, 2 ♀♀, 31-VII-2021. AQ: 2 ♂♂, 3 ♀♀, 08-VIII-2019; 3 ♂♂, 1 ♀, 31-VII-2021. AW: 1 ♀, 04-VIII-2020/08-VIII-2020; 1 ♂, 29-VII-2021. AY: 1 ♂, 1 ♀, 04-VIII-2020/08-VIII-2020. BA: 1 ♂, 2 ♀♀, 28-VI-2021. BB: 1 ♂, 1 ♀, 26-VI-2021. BC: 5 ♀♀, 06-VIII-2019. BD: 2 ♂♂, 1 ♀, 06-VIII-2019. BG: 2 ♀♀, 05-VIII-2020. Species is widely distributed throughout the study area. Very well established in the forest area where it is under stones or in the leaf litter. It has also been observed in roadside ditches and forest trails, in montane meadows, and along with forest river courses It was found at a wide altitude range (1,258-1,970 m a.s.l.). ENDE element.

Poecilus (Macropoecilus) kugelanni (Panzer, 1797)

AC: 3 ♀♀, 27-VI-2021. Species observed at 1,560 m a.s.l. showing a heliophilous behaviour on a forest track. EURP element.

Poecilus (Poecilus) versicolor (Sturm, 1824)

K: 1 ♀, 25-VI-2021. AG: 1 ♀, 06-VIII-2020. AU: 1 ♂, 29-VI-2021. This species was observed under stones on meadows and forest road tracks covering an altitudinal range from the bottom of the valley to elevated areas (1,274-1,800 m a.s.l.). SIER element.

Pterostichus (Argutor) vernalis (Panzer, 1796)

C: 1 ♂, 30-VII-2021. AX: 1 ♂, 06-VIII-2020. It was punctually found under stones at two well-differentiated localities, a path and a bog at low and medium altitudes (1,285 and 1,525 m a.s.l.). PALE element.

Pterostichus (Feronidius) brevipennis brevipennis Chevrolat, 1840

W: 1 ♀, 06-VIII-2020; 1 ♂, 1 ♀, 27-VI-2021; 1 ♂, 1 ♀, 01-VIII-2021. X: 2 ♂♂, 1 ♀, 01-VIII-2021. Z: 1 ♀, 09-VIII-2019. AS: 1 ♂, 31-VII-2021. AW: 1 ♂, 29-VII-2021. BB: 3 ♂♂, 3 ♀♀, 26-VI-2021. Not very abundant species but observed always sheltered under stones in diverse environments (Pyrenean oak and broom path, mowing meadow, birch grove, broom grove, stream bank, track ditch), at low and medium altitudes (1,260-1,500 m a.s.l.). ENDE element.

Pterostichus (Oreophilus) cantaber (Chaudoir, 1868) (Figs. 8a–b, d–e, 9a–b)

H: 1 ♂, 07-VIII-2019. K: 1 ♂, 25-VI-2021; 1 ♀, 30-VII-2021. J: 2 ♂♂, 2 ♀♀, 07-VIII-2020. M: 1 ♂, 03-VIII-2021. Q: 1 ♀, 04-VIII-2020. S: 1 ♂, 1 ♀, 04-VIII-2020/08-VIII-2020. Z: 1 ♂, 09-VIII-2019. AB: 1 ♀, 02-VIII-2021. AH: 1 ♀, 02-VIII-2021. AI: 1 ♀, 02-VIII-2021. AP: 4 ♂♂, 31-VII-2021. AQ: 3 ♀♀, 08-VIII-2019; 1 ♀, 09-VIII-2019; 2 ♀♀, 31-VII-2021. AU: 2 ♂♂, 25-VI-2021/29-VI-2021. AW: 2 ♂♂, 3 ♀♀, 04-VIII-2020; 1 ♀, 04-VIII-2020/08-VIII-2020; 1 ♀, 25-VI-2021; 2 ♂♂, 1 ♀, 29-VII-2021. BA: 2 ♂♂, 28-VI-2021. BB: 1 ♀, 04-VIII-2020; 5 ♂♂, 1 ♀, 26-VI-2021. BC: 3 ♀♀, 06-VIII-2019. BD: 1 ♀, 06-VIII-2019. BG: 1 ♀, 05-VIII-2020. It is one of the most conspicuous carabid beetles in the area: large, with sublapidicolous behaviour, it is found in areas with a lot of vegetation (birch trees, gallery forests) or in clearer areas (stream banks, slopes, meadows), at a wide altitude range (1,183-1,835 m a.s.l.). ENDE element.

Pterostichus (Phonias) strenuus (Panzer, 1797)

C: 1 ♂, 30-VII-2021. J: 1 ♀, 07-VIII-2020. M: 1 ♂, 28-VI-2021. W: 1 ♂, 06-VIII-2020; 1 ♂, 01-VIII-2021. AW: 1 ♀, 04-VIII-2020. AX: 1 ♀, 06-VIII-2020. This species was observed seeking refuge under stones roadside ditches, meadows, and bogs. Available data locate it in an altitudinal strip between 1,230-1,525 m a.s.l. SIER element.

Pterostichus (Pseudomaseus) carri Angus, Galián & Wrase & Chaladze, 2009

C: 2 ♀♀, 30-VII-2021. J: 1 ♂, 07-VIII-2020. Z: 1 ♀, 09-VIII-2019. AC: 1 ♂, 1 ♀, 27-VI-2021. AD: 1 ♂, 06-VIII-2020. AU: 1 ♀, 25-VI-2021/29-VI-2021. AW: 1 ♂, 24-VI-2021; 2 ♂♂, 1 ♀, 25-VI-2021; 1 ♀, 29-VII-2021. Species with a hygrophilous tendency that is preferably located on riverbanks, wet meadows, bogs, or in wet ditches and track slopes. In these places, it usually seeks refuge under stones. It was observed at mid-low altitude (1,260-1,590 m a.s.l.). IBMG element.

Pterostichus (Pterostichus) cristatus heydenianus Jacobson, 1907

D: 2 ♀♀, 07-VIII-2019. F: 1 ♂, 4 ♀♀, 07-VIII-2020. H: 3 ♂♂, 1 ♀, 07-VIII-2019. J: 4 ♂♂, 1 ♀, 07-VIII-2020. K: 1 ♂, 2 ♀♀, 25-VI-2021. Q: 1 ♂, 04-VIII-2020. Z: 4 ♂♂, 1 ♀, 09-VIII-2019. AG: 1 ♀, 06-VIII-2020. AN: 2 ♂♂, 1 ♀, 31-VII-2021. AQ: 1 ♂, 1 ♀, 31-VII-2021. AT: 2 ♂♂, 10-VIII-2019. AW: 1 ♂, 24-VI-2021; 1 ♀, 25-VI-2021; 2 ♂♂, 29-VII-2021. AZ: 1 ♂, 1 ♀, 05-VIII-2020. BB: 2 ♂♂, 3 ♀♀, 04-VIII-2020. BC: 2 ♂♂, 1 ♀, 06-VIII-2019. BE: 1 ♂, 05-VIII-2020. Frequent and widely distributed species in the altitude range from 1,183 to 1,556 m a.s.l., especially in the humid forests (birch groves, riparian forest), or associated with them (stream banks, ditches and slopes of tracks forests, meadows and forest clearings). There is a single record at a high altitude (1,800 m a.s.l.) linked to a moist substrate. It is common to find it in syntopy with P. (O.) cantaber. ENDE element.

Steropus (Steropidius) gallega (Fairmaire, 1859)

P: 1 ♂, 04-VIII-2020/08-VIII-2020. This species is usually very frequent in forest areas of the Cantabrian zone but is uncommon in this study. Only one specimen was collected by installing pitfall traps in a place with elms, maples and ash trees at 1,261 m a.s.l. ENDE element.

Amara (Amara) aenea (DeGeer, 1774)

D: 2 ♀♀, 30-VII-2021. F: 1 ♂, 07-VIII-2020. G: 2 ♂♂, 2 ♀♀, 07-VIII-2020. W: 1 ♀, 06-VIII-2020. AD: 6 ♂♂, 6 ♀♀, 27-VI-2021. AE: 3 ♂♂, 6 ♀♀, 06-VIII-2020. Typical species of open areas more exposed to insolation (sunny meadows and paths). It was located at the bottom of a valley or on south-facing slopes at low and medium altitudes (1,390-1,621 m a.s.l.). PALE element.

Amara (Amara) communis (Panzer, 1790)

AW: 1 ♂, 25-VI-2021. Uncommon species of which a single specimen was collected in a meadow at the bottom of the valley (1,260 m a.s.l.). ASER element.

Amara (Amara) familiaris (Duftschmid, 1812)

W: 1 ♂, 1 ♀, 06-VIII-2020; 1 ♂, 4 ♀♀, 27-VI-2021. AW: 1 ♀, 24-VI-2021. This species was observed occasionally in open areas (sunny pathway and runway ditch) at low altitudes (1,260-1,390 m a.s.l.). ASER element.

Amara (Amara) lucida (Duftschmid, 1812)

W: 1 ♀, 06-VIII-2020; 1 ♀, 27-VI-2021. Uncommon species that was found in a place with Pyrenean oaks, brooms and mowing meadows (1,390 m a.s.l.). TEUM element.

Amara (Amara) montivaga Sturm, 1825

AW: 1 ♂, 24-VI-2021. Scarce species that was found wandering along the path ground at bottom of the valley (1,260 m a.s.l.). TUER element.

Amara (Bradytus) apricaria (Paykull, 1790)

AF: 1 ♂, 02-VIII-2021. Unusual species whose only specimen was found under a stone in a meadow located at 1,665 m a.s.l. HOLA element.

Amara (Percosia) equestris equestris (Duftschmid, 1812)

Y: 2 ♂♂, 1 ♀, 01-VIII-2021. Species that was only observed on slopes facing south (1,555 m a.s.l.), whose specimens were found under stones in an area with brooms and dense grass cover. SIER element.

Amara (Zezea) kulti Fassati, 1947

B: 1 ♀, 30-VII-2021. A single specimen was found under a stone in a wet meadow at 1,617 m a.s.l. EUME element.

Curtonotus aulicus (Panzer, 1797)

D: 1 ♂, 30-VII-2021. BA: 1 ♂, 28-VI-2021. Unusual species found under stones in birch forest between 1,290-1,500 m a.s.l. ASER element.

Zabrus (Cantabrozabrus) consanguineus Chevrolat, 1865

AK: 1 ♂, 02-VIII-2021. AL: 2 ♂♂, 2 ♀♀, 02-VIII-2021. Species that was only observed at high altitudes (1,970-2,002 m a.s.l.), in the surroundings of El Tambarón summit. It was found under stones in montane meadows and at the base of rocky outcrops. ENDE element.

Zabrus (Iberozabrus) silphoides asturiensis Heyden, 1880

D: 1 ♀, 07-VIII-2019; 1 ♂, 30-VII-2021. Uncommon species that was only observed under stones of the ditch of a track that runs next to a meadow with brooms in the upper of Rabón valley (1,500 m a.s.l.) ENDE element.

Agonum (Agonum) muelleri (Herbst, 1784)

B: 1 ♂, 30-VII-2021. Hygrophilous and scarce species that was only observed in a bog located at 1,617 m a.s.l. SIER element.

Agonum (Olisares) sexpunctatum (Linnaeus, 1758)

B: 1 ♂, 1 ♀, 30-VII-2021. F: 1 ♂, 1 ♀, 07-VIII-2020. K: 1 ♂, 25-VI-2021. AD: 1 ♀, 06-VIII-2020; 4 ♂♂, 2 ♀♀, 27-VI-2021. Hygrophilous species found in open and sunny places but with very wet soils located at 1,350-1,617 m a.s.l. SIER element.

Agonum (Olisares) viridicupreum (Goeze, 1777)

B: 1 ♀, 30-VII-2021. AD: 1 ♂, 1 ♀, 06-VIII-2020; 2 ♂♂, 27-VI-2021. AW: 1 ♂, 29-VII-2021. Hygrophilous species observed on moist soils of stream edges, bogs and wet meadows at 1,260-1,617 m a.s.l. CAER element.

Anchomenus (Anchomenus) dorsalis (Pontoppidan, 1763)

Q: 2 ♂♂, 04-VIII-2020. Very hygrophilous species exclusively found under stones on the edge of a cultivated meadow next to a river (1,183 m a.s.l.). PALE element.

Limodromus assimilis (Paykull, 1790)

H: 1 ♂, 07-VIII-2019. K: 1 ♂, 2 ♀♀, 25-VI-2021. J: 1 ♂, 3 ♀♀, 07-VIII-2020. Z: 1 ♀, 09-VIII-2019; 3 ♂♂, 01-VIII-2021. AV: 2 ♂♂, 04-VIII-2020/08-VIII-2020. AW: 2 ♂♂, 1 ♀, 04-VIII-2020; 1 ♂, 4 ♀♀, 04-VIII-2020/08-VIII-2020; 2 ♂♂, 3 ♀♀, 24-VI-2021; 2 ♂♂, 25-VI-2021; 1 ♂, 29-VII-2021. AX: 1 ♀, 06-VIII-2020. BA: 1 ♂, 28-VI-2021. BB: 1 ♀, 04-VIII-2020. Hygrophilous species that seeks refuge under stones and bark of broadleaved trees. It was observed in gallery forest, birch groves, stream banks, sidewalks and roadside ditches with wet substrate between 1,260-1,458 m a.s.l. ASER element.

Paranchus albipes (Fabricius, 1792)

B: 2 ♀♀, 30-VII-2021. F: 1 ♂, 2 ♀♀, 07-VIII-2020. H: 1 ♀, 07-VIII-2019; 1 ♂, 07-VIII-2020. J: 1 ♀, 07-VIII-2020. K: 1 ♀, 25-VI-2021. Q: 1 ♂, 2 ♀♀, 04-VIII-2020. T: 1 ♂, 1 ♀, 04-VIII-2020. Z: 3 ♂♂, 2 ♀♀, 09-VIII-2019. AB: 4 ♂♂, 06-VIII-2020; 1 ♀, 02-VIII-2021. AD: 1 ♂, 06-VIII-2020. AW: 1 ♂, 24-VI-2021; 1 ♀, 29-VII-2021. AX: 1 ♂, 06-VIII-2020. Very hygrophilous species, present in different places in the sampled area. It takes refuge under stones on banks of streams, bogs, humid forests and ruderal areas with stagnant rainwater. It was observed at low and medium altitudes (1,183-1,617 m a.s.l.). WPAL element.

Platyderus sp.

AK: 1 ♂, 02-VIII-2021. Unusual species with sublapidicolous behaviour found in a montane meadow with calcarenite substrate at 1,970 m a.s.l. ENDE element.

Calathus (Calathus) brevis Gautier des Cottes, 1866

AF: 1 ♂, 02-VIII-2021. AI: 1 ♀, 02-VIII-2021. AK: 1 ♂, 02-VIII-2021. BG: 1 ♀, 05-VIII-2020. A species not very abundant in the study area, observed under stones, in open spaces (meadows, ruderal environments, and broom) above the upper limit of forest (1,654-1,970 m a.s.l.). ENDE element.

Calathus (Calathus) fuscipes punctipennis Germar, 1823

B: 2 ♂♂, 30-VII-2021. G: 2 ♂♂, 1 ♀, 07-VIII-2020. Z: 1 ♂, 09-VIII-2019. AE: 1 ♂, 2 ♀♀, 06-VIII-2020. AF: 1 ♀, 02-VIII-2021. Species with sublapidicolous behaviour, observed in meadows and ruderal substrates at low and medium altitudes (1,423-1,665 m a.s.l.). MEDT element.

Calathus (Iberocalathus) rotundatus rotundatus Jacquelin du Val, 1857

W: 3 ♂♂, 27-VI-2021; 4 ♂♂, 3 ♀♀, 01-VIII-2021. AB: 1 ♂, 06-VIII-2020. AF: 2 ♂♂, 1 ♀, 02-VIII-2021. These specimens were observed on sunny south-facing slopes. They were found under stones in ruderal areas next to meadows and small stands of Pyrenean oak and broom at 1,390-1,665 m a.s.l. ENDE element.

Calathus (Neocalathus) asturiensis Vuillefroy, 1866

AI: 1 ♂, 1 ♀, 02-VIII-2021. A not very abundant species, observed under stones next to brooms above the upper limit of the forest (1,835 m a.s.l.). ENDE element.

Calathus (Neocalathus) melanocephalus (Linnaeus, 1758)

W: 1 ♂, 2 ♀♀, 01-VIII-2021. X: 1 ♂, 01-VIII-2021. AK: 5 ♂♂, 3 ♀♀, 02-VIII-2021. AN: 1 ♀, 31-VII-2021. AW: 1 ♂, 1 ♀, 04-VIII-2020; 2 ♀♀, 04-VIII-2020/08-VIII-2020; 1 ♂, 29-VII-2021. BG: 1 ♂, 26-VI-2021. Frequent species in open and sunny spaces where it usually finds shelter under stones and fallen trunks. It appears in ruderal areas, mountain meadows, and scattered stands of Pyrenean oak and broom. Observed in almost the entire altitude range studied (1,260-1,970 m a.s.l.). PALE element.

Calathus (Amphyginus) rotundicollis Dejean, 1828

H: 3 ♂♂, 2 ♀♀, 07-VIII-2019. J: 2 ♀♀, 07-VIII-2020. K: 3 ♀♀, 25-VI-2021. L: 2 ♀♀, 09-VIII-2019/11-VIII-2019. M: 4 ♂♂, 1 ♀, 28-VI-2021; 4 ♀♀, 03-VIII-2021. N: 1 ♀, 04-VIII-2020/08-VIII-2020. O: 1 ♂, 9 ♀♀, 04-VIII-2020/08-VIII-2020. P: 7 ♀♀, 04-VIII-2020/08-VIII-2020. R: 1 ♂, 3 ♀♀, 04-VIII-2020/08-VIII-2020. S: 1 ♀, 04-VIII-2020/08-VIII-2020. W: 3 ♀♀, 06-VIII-2020; 2 ♂♂, 2 ♀♀, 27-VI-2021; 4 ♂♂, 1 ♀, 01-VIII-2021. Z: 1 ♀, 09-VIII-2019; 1 ♂, 1 ♀, 01-VIII-2021. AC: 2 ♀♀, 27-VI-2021. AP: 1 ♂, 2 ♀♀, 31-VII-2021. AS: 1 ♂, 1 ♀, 31-VII-2021. AW: 2 ♂♂, 8 ♀♀, 04-VIII-2020/08-VIII-2020; 1 ♂, 4 ♀♀, 29-VII-2021. AX: 1 ♀, 06-VIII-2020. AY: 3 ♀♀, 04-VIII-2020/08-VIII-2020. BB: 1 ♂, 26-VI-2021. BC: 2 ♂♂, 3 ♀♀, 06-VIII-2019. Very abundant and widely distributed species throughout the study area, with a special preference for wet birch forest soils or its influenced areas (gallery forests, ditches, slopes of forest tracks, and man-made meadows in the valley). It is observed especially at low altitudes and becomes rarefied when the forest begins to disappear (1,193-1,560 m a.s.l.). WEUR element.

Laemostenus (Actenipus) oblongus ellipticus (Schaufuss, 1862)

D: 1 ♀, 07-VIII-2019. R: 1 ♀, 04-VIII-2020/08-VIII-2020. AY: 1 ♀, 04-VIII-2020/08-VIII-2020. Although this species was expected to be found abundantly on forest soils, it is very uncommon. It was only observed in two places of the birch forest, and in a montane meadow near a forest at 1,220-1,500 m a.s.l. ENDE element.

Synuchus vivalis vivalis (Illiger, 1798)

V: 1 ♀, 08-VIII-2019. W: 3 ♂♂, 1 ♀, 01-VIII-2021; 1 ♀, 02-VIII-2021. It was only observed in two places: a dead specimen by a village lamppost (probably attracted by artificial light, perhaps flying from a far distance), and the others were collected on a south-facing path with Pyrenean oaks, brooms and near mowed meadows (1,390 m a.s.l.). ASER element.

Its restricted presence in the valley could be related to the limited extension of oak, areas for which this carabid could show preference as it has a certain trophic specificity for Curculio species. This has already been suggested by Jeannel (‍1942), although Lindroth (‍1956) shows that the distribution area of Synuchus is wider than that of these Curculionidae species. Synuchus vivalis may show a certain preference but not dependence for this type of prey.

Anisodactylus (Anisodactylus) binotatus (Fabricius, 1787)

C: 2 ♂♂, 1 ♀, 30-VII-2021. Z: 1 ♂, 09-VIII-2019. AW: 4 ♂♂, 1 ♀, 29-VII-2021. It was observed under stones in open spaces with a moist substrate, meadows and bogs, at low and medium altitudes (1,260-1,525 m a.s.l.). PALE element.

Anisodactylus (Anisodactylus) hispanus Puel, 1931

C: 2 ♂♂, 30-VII-2021. AA: 2 ♂♂, 3 ♀♀, 27-VI-2021. AC: 3 ♂♂, 2 ♀♀, 27-VI-2021. As in A. (A.) binotatus, which is syntopic in some places, it likes open spaces with edaphic moisture. It was observed under stones, in bogs, and in wet ditches of forest tracks at low and medium altitudes (1,440-1,560 m a.s.l.). ENDE element.

Harpalus (Harpalus) affinis (Schrank, 1781)

B: 4 ♂♂, 30-VII-2021. C: 6 ♂♂, 3 ♀♀, 30-VII-2021. F: 1 ♀, 07-VIII-2020. G: 1 ♀, 07-VIII-2020. M: 1 ♂, 28-VI-2021. W: 2 ♂♂, 27-VI-2021. Z: 3 ♂♂, 1 ♀, 09-VIII-2019. AC: 3 ♂♂, 2 ♀♀, 27-VI-2021. AE: 2 ♂♂, 06-VIII-2020. AW: 1 ♂, 24-VI-2021. BB: 2 ♂♂, 1 ♀, 26-VI-2021. This species prefers meadows or ruderal areas and usually seeks shelter under stones. In the study area, it is observed mainly on south-facing slopes, at 1,230-1,621 m a.s.l. ASER element.

Harpalus (Harpalus) contemptus Dejean, 1829

C: 1 ♂, 1 ♀, 30-VII-2021. M: 1 ♀, 28-VI-2021. AC: 2 ♂♂, 27-VI-2021. Species that usually lives on meadows and ruderal areas and was found at an altitude range between 1,230 and 1,560 m a.s.l. In the study area, syntopy with H. (H.) affinis has been observed. ENDE element.

Harpalus (Harpalus) franzi Mateu, 1954

BB: 3 ♂♂, 1 ♀, 26-VI-2021. Very rare species with very local distribution in the northwestern quadrant of the Iberian Peninsula. Of the four sampling campaigns carried out, this species was found exclusively at one point (1,390 m a.s.l.). All specimens were collected under stones, on side of a forest track that runs through a birch forest. ENDE element.

Harpalus (Harpalus) honestus (Duftschmid, 1812)

K: 1 ♂, 25-VI-2021. Unusual species whose only specimen studied was found under a stone on side of a track that crossed a birch forest (1,350 m a.s.l.). TUER element.

Harpalus (Harpalus) decipiens Dejean, 1829

X: 1 ♂, 01-VIII-2021. AD: 2 ♂♂, 27-VI-2021. AF: 5 ♂♂, 02-VIII-2021. AH: 3 ♂♂, 02-VIII-2021. AI: 1 ♂, 02-VIII-2021. AK: 2 ♀♀, 02-VIII-2021. Specimens were observed in open spaces far from the forest (meadows, brooms, and roadside ditches). In the sampling area, its distribution is limited to slopes of valleys and mountains near La Forcada and Alto de Vivero, in an altitude range between 1,500-1,970 m a.s.l. Of all the Harpalus species found, this is the most orophilic. LION element.

Harpalus (Harpalus) rubripes (Duftschmid, 1812)

BB: 1 ♂, 26-VI-2021. The only specimen studied was found at a low altitude (1,390 m a.s.l.), under a stone in a birch forest. EURP element.

Harpalus (Harpalus) rufipalpis rufipalpis Sturm, 1818

BG: 1 ♂, 26-VI-2021. Rare species in the study area. The only specimen studied was found under a stone on a montane meadow near a stream (1,654 m a.s.l.). SOER element.

Harpalus (Harpalus) serripes (Quensel in Schönherr, 1806)

K: 2 ♂♂, 1 ♀, 25-VI-2021. W: 2 ♂♂, 1 ♀, 27-VI-2021. AW: 1 ♀, 24-VI-2021. Species limited to a few low altitude ruderal places (1,260-1,390 m a.s.l.). It was observed wandering along a forest track and under stones in ditches. CAEM element.

Harpalus (Harpalus) subcylindricus Dejean, 1829

K: 1 ♂, 25-VI-2021. The unique specimen studied was found under a stone on the path side that crosses the birch forest at a low altitude (1,350 m a.s.l.). CEUR element.

Harpalus (Harpalus) tardus (Panzer, 1797)

X: 1 ♀, 01-VIII-2021. The only specimen studied was found under a stone in a broom grove at 1,500 m a.s.l. ASER element.

Ophonus (Metophonus) rufibarbis (Fabricius, 1792)

W: 2 ♀♀, 06-VIII-2020; 1 ♀, 01-VIII-2021. AN: 1 ♂, 31-VII-2021. AW: 3 ♂♂, 2 ♀♀, 24-VI-2021; 2 ♂♂, 25-VI-2021; 2 ♂♂, 29-VII-2021. AX: 1 ♂, 06-VIII-2020. BG: 1 ♂, 26-VI-2021. The species was found under stones in open spaces such as meadows, ruderal areas, or sparsely populated paths. It was observed at an altitudinal range between 1,260-1,654 m a.s.l. TUME element.

Ophonus (Ophonus) ardosiacus Lutshnik, 1922

AF: 1 ♂, 02-VIII-2021. The unique specimen studied was found under a stone on a montane meadow, at 1,665 m a.s.l. MEDT element.

Pseudoophonus (Pseudoophonus) rufipes (DeGeer, 1774)

D: 1 ♂, 1 ♀, 30-VII-2021. F: 2 ♀♀, 07-VIII-2020. G: 7 ♂♂, 1 ♀, 07-VIII-2020. L: 1 ♂, 09-VIII-2019/11-VIII-2019. V: 1 ♀, 07-VIII-2020. W: 1 ♀, 06-VIII-2020. AB: 1 ♂, 06-VIII-2020. AE: 1 ♂, 1 ♀, 06-VIII-2020. AW: 1 ♂, 25-VI-2021. AX: 1 ♀, 06-VIII-2020. Species observed in open spaces such as meadows, ruderal places and sunny paths located at medium-low altitude range (1,260-1,621 m a.s.l.). It was also attracted by the artificial light of the street lamps in the village. PALE element.

Typsiharpalus bonvouloiri (Vuillefroy, 1866)

W: 1 ♂, 27-VI-2021. AF: 1 ♂, 02-VIII-2021. AG: 1 ♂, 06-VIII-2020. AP: 1 ♂, 31-VII-2021. BB: 7 ♂♂, 26-VI-2021. BH: 4 ♂♂, 26-VI-2021. Species with sublapidicolous behaviour found in very different localities such as birch forest, montane meadows, Pyrenean oak forest paths and ruderal areas in a wide altitudinal range (1,390-1,804 m a.s.l.). ENDE element.

Acupalpus (Acupalpus) brunnipes (Sturm, 1825)

AD: 1 ♀, 06-VIII-2020. The only specimen studied was collected on the sunny bank of a stream that crosses a path located at 1,590 m a.s.l. TEUM element.

Stenolophus teutonus (Schrank, 1781)

B: 2 ♂♂, 3 ♀♀, 30-VII-2021. F: 3 ♂♂, 07-VIII-2020. W: 1 ♂, 27-VI-2021. Z: 1 ♀, 09-VIII-2019. AD: 3 ♂♂, 4 ♀♀, 06-VIII-2020; 6 ♂♂, 3 ♀♀, 27-VI-2021. Hygrophilous species was found on the banks of streams, bogs or in soils that temporarily retain high humidity such as road ditches and sidewalks (1,390-1,617 m a.s.l.). WPAL element.

Badister (Badister) bullatus (Schrank, 1798)

AD: 1 ♀, 27-VI-2021. AW: 1 ♂, 25-VI-2021. BG: 1 ♂, 05-VIII-2020. Hygrophilous species, not very abundant, living near small river courses and in a ditch with very humid soil, at low and medium altitudes (1,260-1,654 m a.s.l.). WMED element.

Chlaenius (Chlaeniellus) tristis (Schaller, 1783)

AD: 1 ♀, 06-VIII-2020. Hygrophilous species was only observed on the sunny edge of a stream that crosses a forest track (1,590 m a.s.l.). PALE element.

Cymindis (Cymindis) alternans alternans Rambur, 1837

W: 4 ♂♂, 27-VI-2021; 1 ♀, 01-VIII-2021. AF: 1 ♂, 02-VIII-2021. Species exclusively observed under stones in two places facing south: in a path between Pyrenean oaks and brooms, and on a ditch of a track dominated by brooms (1,390-1,665 m asl). ENDE element.

Cymindis (Menas) miliaris (Fabricius, 1801)

AK: 1 ♀, 02-VIII-2021. Species very localized as sublapidicolous in high montane grassland (1,970 m a.s.l.). TSER element.

Apristus europaeus Mateu, 1980

AD: 2 ♀♀, 27-VI-2021. Species located on the strongly insolated substrate of a forest path at medium altitude (1,590 m a.s.l.). TUME element.

Microlestes sp.

BH: 1 ♀, 26-VI-2021. Specimen located at a high altitude (1,804 m a.s.l.) under a stone on a mountain meadow next to shrubby vegetation. Element (not stated).

Syntomus foveatus (Geoffroy en Fourcroy, 1785)

C: 1 ♀, 30-VII-2021. W: 1 ♂, 27-VI-2021. AD: 1 ♂, 1 ♀, 06-VIII-2020. AF: 1 ♂, 02-VIII-2021. AK: 1 ♀, 02-VIII-2021. Sublapidicolous species, collected at very diverse altitudes (1,390-1,970 m a.s.l.) in open and sunny spaces at the bottom of the valley, slopes and summits. PALE element.

Masoreus wetterhallii wetterhallii (Gyllenhal, 1813)

W: 1 ♀, 06-VIII-2020. A specimen found on a path of Pyrenean oaks with brooms, close to mowing meadows located at a low altitude (1,390 m a.s.l.). WPAL element.

Corotypes

The biogeographical analysis developed from the carabid species observed in the studied area shows 22 chorological types (Fig. 10) among which the Iberian Endemic element stands out with 35 spp, which represents 35% of the total and 92% of the biogeographical category “Iberian Distribution”. In the category of “Wide Distribution” (20% of the total), the Palearctic elements are highlighted (10 spp, 20% of the total and 50% of the category). In the “Asiatic European” category (31% of the total) the most important elements are Asiatic-European (9 spp, 9% of the total and 29% of the category), the Sibirian-European elements (6 spp, 6% of the total and 19% of the category) and also European (5 spp, 5% of the total and 16% of the category). Finally, the “European Mediterranean” category (11% of the total), is scarce representation in the study area, and distributed among several chorological types (biogeographical element) with only one, two or three species, so we cannot highlight any of them (see Fig. 10).

Discussion[Up]

Taxonomic aspects

Three of the species studied offer certain difficulties in their taxonomic identification, so it was considered appropriate to clarify some doubts and challenges raised with the morphological study of the specimens.

Trechus (Trechus) gallaecus (Figs. 4a, 5) is an endemic species of the mountain reliefs of the northwestern quadrant of the Iberian Peninsula. It was described by Jeannel (‍1921) from a female specimen (type locality: Caboalles, León), so he could not contribute to the study of the aedeagus, not even in his monograph about Trechinae (see ‍Jeannel, 1927: 263). This author recognizes the great resemblance of this species to T. (T.) suturalis (Figs. 4b) with the added difficulty that both species live in the Cantabrian mountains. In the identification key provided by Jeannel (‍1927) on the “T. pyrenaeus group”, the observable differences between the females of both species are mostly limited to quantitative traits. In T. gallaecus these differences make the specimens slightly larger and with slightly longer antennomeres, while in T. suturalis, the specimens are smaller, showing subtly shorter antennomeres. These differences are not completely decisive, especially when both species are syntopic as in a large part of their distribution area. This is the case of the localities sampled in this study. To ratify the presence of one or another species in a certain area it is necessary to observe qualitative characteristics that allow its unequivocalidentification. In the genus Trechus, this is usually achieved by studying the external morphology of the aedeagus and the shape and arrangement of the sclerotized elements of the internal sac. For this reason, it is essential to have a good understanding of the aedeagus of both species (Figs. 6–7). Although Jeannel (‍1927) illustrated the aedeagus of T. suturalis and later Jeanne (‍1988) did the same with the aedeagus of T. gallaecus, both graphic descriptions do not do justice to the anatomical reality of these structures. In T. gallaecus the internal sac was not illustrated, so we only know what the outline of the aedeagus looks like from a very basic drawing. The aedeagus of T. suturalis is better known because Jeannel (‍1927) did draw the pieces of the internal sac, however, the contour (curvature) of the middle lobe does not coincide with the one later drawn (without the detail of the internal sac) in Jeanne (‍1988).

There are two species of Oreophilus Chaudoir, 1838 in the Cantabrian area: P. (O.) cantaber (Fig. 8a) and Pterostichus (Oreophilus) franzi Nègre, 1955 (Fig. 8c), both endemic and whose distribution overlaps in the western sector of this range. The study of the specimens collected in the high valley and mountainous foothills of Salientes (51 exx) shows that they are all attributable to P. (O.) cantaber (Fig. 8a, d). However, two females collected together with other specimens (males and females) in two different places show the habitus of Pterostichus (Oreophilus) franzi Nègre, 1955 (Fig. 8b–c): they show a more transverse pronotum than the other specimens and also present a sutural denticle at the apex of the elytra (Fig. 8e–f), a characteristic shared with many other females already presenting a Pterostichus (Oreophilus) cantaber habitus. It would be expected that these features would reveal the syntopic presence of both Oreophilus species in this geographical area, but the study of the genitalia of all males confirmed that there is only a single species present, P. (O.) cantaber (Fig. 9a–b). This fact evidences the inconsistency or unreliability of the external characters invoked by Nègre (‍1955) and later ratified by Serrano (‍2021) in the dichotomous keys to externally differentiate both species. This variability shown byP. (O.) cantaber may have led to the number of records (and citations in articles already published) that reveal the syntopy of both species. It would be interesting to study the specimens collected in all these localities again, considering that the external characters that were given as differentiators between both species can only be taken as indicative, and the shape of the aedeagus is for the moment the only reliable character (Fig. 9).

Carabid forest fauna

From the carabid fauna observed in this study, a list of typical forest species that show certain preferences for occupying this type of environment can be drawn up. Due to their abundance and presence in various wooded localities in the area, the most representative species are C. (A.) rotundicollis, P. (O.) cantaber, P. (P.) cristatus heydenianus, C. cantabricus cantabricus, T. (T.) suturalis, T. (T.) gallaecus, L. (L.) barnevillei, C. (Ch.) lineatus lateralis, and B. (P.) deletum schulerianum. Other species that were only observed in the humid forest, albeit not in abundance, are C. spinicollis, C. (O.) luetgensi getschmanni, C. (A.) nemoralis lamadridae, and O. (O. ) tachysoides. Surprisingly, frequent and even dominant species in other wooded areas of the Cantabrian range such as S. (S.) gallega and L. (A.) oblongus ellipticus, were almost anecdotal in these forests of Salientes upper valley. Limodromus assimilis, P. (F.) brevipennis brevipennis, N. rufipes, and N. biguttatus, were observed in forested areas, but were also present in the faunal composition of other habitats such as riparian environments, ruderal environments that store moisture, etc.

Riparian and marshy carabid fauna

A set of species that are forced to live on the banks of running watercourses, still waters, and also in open spaces with high edaphic humidity (bogs, peat bogs, springs, etc.) are presented and commented on in this paragraph. The abundance presence in various localities allows a selection of the most representative species of these wetlands: N. (E.) jockischii orensis, N. (N.) brevicollis, B. (N.) ibericum, B. (N.) callosum subconnexum, B. (B.) tibiale, B. (O.) strictum, B. (Ph.) guadarramense, B. (Ph.) guttula, B. (P.) tetracolum, P. (Ph.) carri, A. (O.) sexpunctatum, P. albipes, and S. teutonus. Sinechostictus (S.) stomoides especially noteworthy since, although it was riparian, it was present specifically in fluvial sections that run through the forest and, therefore, are rich in leaf litter, which agrees with the observations of Ortuño & Toribio (‍2005). The following species were observed more rarely: C. (R.) melancholicus costatus, C. (C.) fossor, E. (N.) pyrenoeus, T. (T.) parvula, B. (E.) minimum, B. (T.) articulatum, B. (B.) quadrimaculatum, B. (B.) geniculatum geniculatum, B. (B.) leonense, A. (O.) viridicupreum, A. (A.) muelleri, A. (A.) dorsalis, A. (A.) brunnipes, B. (B.) bullatus, and C. (C.) tristis.

It should be noted that L. assimilis, A. (A.) binotatus, and A. (A.) hispanus are species that, in addition to this kind of environment, can also be observed in other habitats that conserve high edaphic humidity. The same can be said concerning T. (T.) fulvus, a highly hygrophilous species that can be found in river courses seeking refuge under stones or in ground interstices.

Carabid fauna of ruderal and open spaces

The most representative set of species typical of spaces without forest cover such as meadows, brooms, sidewalks, ditches and slopes of paths and tracks are discussed below: C. (C.) campestris campestris, C. (M.) macrocephalus macrocephalus, B. (M.) lampros, A. (A.) aenea, C. (C.) fuscipes punctipennis, C. (I.) rotundatus rotundatus, C. (N.) melanocephalus, H. (H.) affinis, H. (H.) decipiens, O. (M.) rufibarbis, P. (P.) rufipes, and T. bonvouloiri.

Other species of Amara (7 spp) and Harpalus (8 spp) were found less frequently, with the especially noteworthy case of H. (H.) franzi as an endemism with a very restricted distribution in the easternmost reliefs of Galicia and the Montes de León (‍Zaballos & Jeanne, 1994). This new report increases the chorological knowledge of this species.

Other scarce and very localized species typically observed in this type of landscape were B. (M.) properans, P. (M.) kugelanni, P. (P.) versicolor, P. (A.) vernalis, P. (Ph.) strenuus, C. aulicus, Z. (C.) consanguineus, Z. (I.) silphoides asturiensis, C. (C.) brevis, C. (N.) asturiensis, O. (O.) ardosiacus, C. (C.) alternans alternans, C. (M.) miliaris, A. europaeus, S. foveatus, and M. wetterhallii wetterhallii.

Leistus (L.) barnevillei represents a noteworthy case, being a forest group species that is also present in supraforestal environments, seeking refuge on slopes and at the base of heather and broom, where they can be found buried forming very numerous colonies. Along with this species, inside the soil in these same open spaces was another species, N. (N.) asturiensis. It is remarkable that this species has not been located in the forests of this valley, because it has been recognized by diverse entomologists as an eminently forest species throughout its distribution area (see ‍Jeanne, 1966, ‍Zaballos & Jeanne, 1994; ‍Serrano, 2003; Ortuño pers. obs.).

Underground carabid fauna

Some specimens of the species studied here were found buried in the ground, such as the already mentioned cases of L. (L.) barnevillei, N. (N.) asturiensis, but also C. spinicollis, T. (T.) gallaecus, T. (T.) suturalis, B. (Ph.) guadarramense, B. (N.) callosum subconnexum, B. (N.) ibericum, B. (O.) strictum, and B. (P.) deletum schulerianum. This is a normal behaviour in many carabids that, due to their hygrophilous requirements, seek moisture and shelter in deep soil levels. However, among all the faunal groups studied, we can only affirm true underground behaviour for two species. On the one hand, T (T.) fulvus, which is recognized as a troglophilic species (‍Ortuño et al., 2017), and for which an important part of the specimens found in this area were observed in cracks and soil interstices. The other species that seem to be fully subterranean is T. (T.) teverganus. Until now, only two specimens (male and female) were known from the subterranean environment of two Asturian localities, Puerto de Ventana and Huerta cave in Teverga, which constitute the typical series (‍Toribio, 2015). The location of six specimens in the subterranean environment (soil interstices at a depth of 40-‍50 centimetres) in the Salientes Valley considerably expands the distribution of this species. Itsobvious troglobiomorphic features and its subterranean life suggest strong isolation in the subsoil, a circumstance that does not occur despite the barriers that apparently separate the known Asturian and Leonese localities. Of this species, one male (unpublished data, Ortuño & Arribas leg. & det.) has been captured in the neighbouring Salentinos valley. Everything indicates that there is an extensive interstitial network, in which the MSS (Mesovoid Shallow Substratum) must play an important role and being responsible of the T. (T.) teverganus distribution over an extensive area of more than 40 km of diameter, strongly broken and separated in valleys and mountains barriers of more than 2,000 m a.s.l.

Conclusions[Up]

The subfamily with the greatest diversity is Harpalinae (61% of the species), the most strongly represented tribes being Harpalini (18 spp), Zabrini (11 spp), Pterostichini (10 spp), Sphodrini (9 spp) and Platynini (6 spp). The most abundant species for each tribe are, respectively, H. (H.) affinis, A. (A.) aenea, C. cantabricus, C. (A.) rotundicollis and L. assimilis. Next in biodiversity is the Trechinae subfamily (23% of the species), with Bembidiini (17 spp) being better represented than Trechini (5 spp). Its most abundant species are, respectively, the riparian B. (N.) ibericum and the forestal T. (T.) suturalis.

The biogeographical analysis of the carabid fauna indicates that most of the species have an “Iberian Distribution” (38%) and, for the most part, are Iberian endemism (35 spp). These species mainly belong to lineages with a large presence in the Eurosiberian region, a circumstance that, added to the high presence of “Asiatic-European”. distribution species (31%), reveals the close biogeographical link between the carabid fauna of this valley and the Eurosiberian Europe.

Some of the most frequent forest species in the main axis of the Cantabrian Mountains such as N. (N.) asturiensis, Pterostichus (Pterostichus) dux Schaufuss, 1862, S. (S.) gallega, Abax parallelepipedus (Piller & Mitterpacher, 1783), y L. (A.) oblongus, were not observed, or were very infrequent in the humid forest of Salientes Valley. This difference is suggestive of the disconnection (or intermittent connection) between both areas, a circumstance that is also evidenced by other examples such as the absence of Fagus sylvatica from the study area.

The forest environment was especially humid as revealed by the abundance of birch trees and hosted a wide range of carabid beetles that combined hygrophily and sciophily. The most representative species by abundance and distribution were C. (A.) rotundicollis, P. (O.) cantaber, P. (P.) cristatus heydenianus, C. cantabricus cantabricus, T. (T.) suturalis, T. (T.) gallaecus, L. (L.) barnevillei, C. (Ch.) lineatus lateralis and B. (P.) deletum schulerianum.

In riparian and marshy environments, species that require high edaphic humidity were observed, many of them in substrates exposed to direct sunlight. They often took refuge in gravel or under stones. The most representative species were N. (E.) jockischii orensis, N. (N.) brevicollis, B. (N.) ibericum, B. (N.) callosum subconnexum, B. (B.) tibiale, B. (O.) strictum, B. (Ph.) guadarramense, B. (Ph.) guttula, B. (P.) tetracolum, P. (Ph.) carri, A. (O.) sexpunctatum, P. albipes and S. teutonus.

Ruderal environments were numerous, and their great faunal heterogeneity varied according to altitude, orientation, type of nearby vegetation, anthropic impact, etc. However, the most representative species can be summarized as B. (M.) lampros, A. (A.) aenea, C. (C.) fuscipes punctipennis, C. (I.) rotundatus rotundatus, C. (N.) melanocephalus, H. (H.) affinis, H. (H.) decipiens, O. (M.) rufibarbis, P. (P.) rufipes and T. bonvouloiri. The location of H. (H.) franzi represents a new record that increases the chorological knowledge of this species, which has a very restricted distribution in the northwestern quadrant of the Iberian Peninsula.

The interstices of the edaphic horizons of several places with humid soils in the valley have allowed the discovery of T. (T.) teverganus, to date a microendemism of the council of Teverga (Asturias). Accompanying this subterranean element is T (T.) fulvus, well known for being a troglophilous species. Probably due to seeking shelter and edaphic moisture, the occupation of soil interstices by imagoes of some species such as L. (L.) barnevillei, N. (N.) asturiensis, C. spinicollis, T. (T.) gallaecus, T. (T.) suturalis, among others was observed.

The inconsistency of the external characters used up to now to externally differentiate P. (O.) cantaber and P. (O.) franzi is highlighted. This may have caused past identification errors, increasing the number syntopic citations for both species. The aedeagus presents diagnostic characters, so the taxonomic problem of identification especially concerns female specimens.