Sexual dimorphism of Dyschiriini (Coleoptera, Carabidae): Comparative morphological SEM study of palpi sensilla and its possible role in intraspecific chemical communication.

Sexual dimorphism in Dyschiriini (Coleoptera, Carabidae) consists of the presence of an autapomorphic sensory area in apical palpomeres of males, here named as Male Palpi Sensory Area (MPSA). In this work, microstructure of palpi, with focus on MPSA, is characterized and formally described using Scanning Electron Microscopy (SEM). Interspecific variability among 13 species and three subgenera of Dyschirius Bonelli, 1810 and one species of Reicheiodes Ganglbauer, 1891 is assessed. Palpi of studied Dyschiriini presented up to 4 sensilla classes (coeloconica, basiconica, digitiformia, trichodea) in both sexes, while males had one more class (sensilla placodea) found grouped in MPSA. Measurements of sensilla and MPSA are provided. Differences among taxa corresponded to development grade of MPSA and its number of sensilla placodea. The MPSA of Dyschirius (Dyschirius) thoracicus Rossi, 1790 were clearly different to the rest of the studied subgenera and species of Dyschirius and Reicheiodes, whose MPSA were similar and had slight intraspecific variability. We suggest that function of MPSA is likely detection of female pheromones, which would evidence chemical communication between sexes. We hypothesize that evolution of MPSA could be related to burrowing habits of Dyschiriini and its possible sexual behavior in soil tunnels. Study of MPSA may help to elucidate phylogenetic relationships among members of the tribe.

Neelipleona and Symphypleona (Collembola) from a Sampling in the Mesovoid Shallow Substratum of the Sierra de Guadarrama National Park (Madrid and Segovia, Spain): Taxonomy and Biogeography.

Megalothorax minimus (Neelidae) and Sphaeridia pumilis (Sminthurididae) had already been identified in surface sampling from Sierra de Guadarrama. In Europe, Sminthurinus gisini (Katiannidae) seems to be associated with environments at specific altitudes, and has little representation in this sampling. Pygmarrhopalites custodum Baquero and Jordana sp. nov. (Arrhopalitidae) coexists with two previously identified surface occurring species of the same family (P. elegans and Arrhopalites caecus). However, P. custodum is more abundant, indicating that it occupies an ecological niche tending to troglophile in the mesovoid shallow substratum (MSS). Moreover, it is also more abundant in the MSS of higher altitude corresponding to the bioclimatic zones cryo-oro-Mediterranean and oro-Mediterranean supra forest. Allacma cryptica Baquero and Jordana sp. nov. (Sminthuridae), is another species that had not been previously detected on the surface in the study area. A. cryptica is an addition to a genus which has eight described species. Gisinurus malatestai (Sminthuridae) appears well represented in the MSS, being a species present very occasionally in the Mediterranean area. Two species of the genera Sminthurides (Sminthurididae) and Fasciosminthurus (Bourletiellidae) have been found, but they could not have been identified to the species level. Finally, a few specimens of Dicyrtomina minuta (Dicyrtomidae), an abundant species on the surface, have been captured.

Taxonomic reconsideration of the subspecific complex of Laemostenus (Antisphodrus) cazorlensis (Mateu, 1953) (Coleoptera, Carabidae, Platyninae).

In this article we present a comparative study between the three subspecies of Laemostenus (Antisphodrus) cazorlensis (Mateu, 1953) (Coleoptera, Carabidae), a representative carabid of the cave fauna of Jaén and Albacete (southern Spain). The aim of this work was to examine the validity of the characters typically used to distinguish the subspecies L. (A.) c. cazorlensis (Mateu, 1953), L. (A.) c. divergens (Mateu, 1953) and L. (A.) c. seguranus (Vives Vives, 1982) and check if they support the actual subspecific classification. For this purpose, a morphometric study of the pronotum and a morphological study of the male and female genitalia were carried out on 161 individuals of the three subspecies from the different geographic territories within the known distribution range of the species. An ANOVA analysis was run to support the results of the morphometric study developed with the total of studied samples. The results suggest that none of the studied characters can be used to characterize any of the subspecific taxa. Besides, the karstic profile of the ground in where this species inhabits could facilitate the genetic flow between its populations, so it is possible that they are not completely isolated. We conclude that the observable differences between individuals of Laemostenus (Antisphodrus) cazorlensis for the studied characters reflect intraspecific variability, and do not support a subspecific classification of the species. We propose the synonymization of the two non-typical subspecies of Laemostenus (Antisphodrus) cazorlensis with the typical one and, therefore, with the specific taxa.

Restoration of two Carabidae (Coleoptera) species from the Sistema Ibérico Ranges (North-Central Iberian Peninsula): Nebria (Nebria) urbionensis Arribas, 1991 and Zabrus (Iberozabrus) cameranus Arribas, 1994, bonae species.

Two endemic taxa of the Northern Iberian System have been rescued from synonymy using the study of external morphology by means of morphometric analysis and genital anatomy. The causes that possibly led to these two taxa erroneously being identified as synonyms are analysed in this research. In the case of Nebria (Nebria) urbionensis versus Nebria (Nebria) vuillefroyi, their confused relationship was caused by the handling of incorrectly labelled specimens and the subsequent interpolation of distribution areas, which led to overestimating the extent of N. (N.) vuillefroyi to the detriment of recognizing N. (N.) urbionensis as a valid species. According to the criterion that is defended in this work, both taxa are steno-endemic and, therefore, deserve protection due to their reduced habitats. The principle of authority applied by experts, based on an error, may, in this case, have been amplified and contributed to chronify the error.                The second case under review is Zabrus (Iberozabrus) cameranus versus Zabrus (Iberozabrus) laurae, which in a recent study of genus Zabrus, were subjected to a totally unjustified synonymy. The origin of such a taxonomic decision must be sought in the concatenation of a series of errors: the number and origin of the specimens studied do not adequately justify the statements and conclusions expressed in the text, the use of a single character (internal sac of the aedeagus) while ignoring other morphological characters, an inadequate taxonomic praxis, and the elaboration of conclusions based on the lack of supposedly-derived characters (that is, relying on symplesiomorphies). All of this does not point towards an adequate reconstruction of the genus systematics.                The uni- and multivariate biometric study, together with the morphological features that are contributed in this work (added to those already recognized initially for these species), allow to affirm that, although the taxa in discussion are nearby species and possibly sister taxa, they are perfectly valid: Nebria (Nebria) urbionensis stat. res.; Zabrus (Iberozabrus) cameranus stat. res. In addition to the morphological differences, both species diverge respectively from N. (N.) vuillefroyi and Z. (I.) laurae by 2% of the COI 1 gene sequence. The geographical ranges of Nebria (N.) urbionensis and Zabrus (I.) cameranus are confined to the Sistema Ibérico Septentrional, and are separated by the high Duero Valley from the ranges of N. (N.) vuillefroyi and Z. (I.) laurae, which are located in the Central System.

Arthropod biodiversity patterns point to the Mesovoid Shallow Substratum (MSS) as a climate refugium.

The determinants of biodiversity patterns in the subterranean habitat called Mesovoid Shallow Substratum (MSS) are not well-understood. In this study, thirty-three scree slopes at high altitudes were selected across the Sierra de Guadarrama National Park in central Spain to investigate the effect of ten environmental variables on the abundance and species diversity of the spider and springtail assemblages from the colluvial MSS. In each locality, a multiperforated PVC tube with a pitfall trap inside was buried up to 1 m deep, and generalized linear models and Mantel tests were used to analyze the effect of mainly climate- and habitat-related variables on the diversity patterns of both taxa. A total of 1143 individual spiders belonging to 54 species and 40 811 springtail individuals belonging to 62 species were collected. The analyses indicated that cold temperatures and the presence of forest cover on the surface significantly enhance richness and abundance in the two taxa. Environmental similarity also had a small positive effect on faunistic similarity. However, the effects of temperature and habitat detected on spider richness and abundance were stronger than on springtails, whereas the reverse was found regarding faunistic similarity. These results indicate that subterranean dwellers respond differently to the same environmental factors, which in turn, points to a different degree of affinity for the MSS. The MSS plays an important role in the survival of high mountain arthropod species, acting as a climate refuge, so the protection of this habitat should be prioritized.

Out of the dark void: Ommatoiulus longicornis n. sp., a new julid from Spain (Diplopoda, Julida) with notes on some troglobiomorphic traits in millipedes.

A new millipede species, Ommatoiulus longicornis n. sp. is described from the subterranean habitat in eastern Spain, and the elongation of its antennae is discussed in relation to the habitat where it dwells. We take the occasion to discuss the elongation of appendages as a troglobiomorphic character in millipedes and shed the light on the various, sometimes controversial, hypotheses that could have led to these modifications in millipedes and other subterranean arthropods.

Distinctive Collembola communities in the Mesovoid Shallow Substratum: First data for the Sierra de Guadarrama National Park (Central Spain) and a description of two new species of Orchesella (Entomobryidae).

Two new species of the genus Orchesella Templeton, 1836 have been identified following intensive sampling in the Colluvial Milieu Souterrain Superficiel (Mesovoid Shallow Substratum, or MSS) of the Sierra de Guadarrama using Subterranean Sampling Devices (SSD). The data were obtained from the first extraction of the traps between May and October of 2015. During a study of the Collembola taxon, 32 different genera (61 species) were identified. The highest representative genus presence in almost all traps was Orchesella, with two new species. One of the two species described had been misidentified until this study was carried out, indicating that their preferential habitat had not been sampled; the second species had never been identified. The community of the Orchesella species in the Colluvial MSS was investigated, leading to the conclusion that this environment has its own assemblage of characteristic species. The opportunity to study specimens that belong to five species of the genus Orchesella, including three previously recollected, has allowed for obtaining reliable information regarding their macrochaetotaxy. A part of this chaetotaxy is proposed as a useful diagnostic tool for the species of the genus. In conclusion, it can be affirmed that this study has demonstrated that the Colluvial Mesovoid Shallow Substratum (Colluvial MSS) has its own fauna, and it supports the hypothesis that it constitutes a new biotope, at least for Collembola.

A new genus and species of Haplobainosomatidae (Diplopoda: Chordeumatida) from the MSS of the Sierra de Guadarrama National Park, central Spain.

The chordeumatidan fauna of the Iberian Peninsula is far from being well known, but recent efforts are improving that knowledge. Samplings carried out in the Milieu Souterrain Superficiel (also known as the Mesovoid Shallow Substratum) on several screes of the Sierra de Guadarrama National Park (central Spain) have led to the discovery of a new species of chordeumatidan millipede. This new species belongs to the family Haplobainosomatidae, which is mainly known from the northern Iberian Peninsula, and thus this is the first record of the family in central Spain. However, the extremely simple gonopods of this species are so different from all other known species of the family that it must be placed in a new genus. In this work, a complete description of the species, named as Guadarramasoma ramosae gen. & sp. nov., with a detailed iconography based on scanning electron microscopy images is provided together with a distribution map and a brief discussion of the implications of this new finding.

Balligratus, new genus of wingless ground beetles from equatorial Andean montane forest (Coleoptera: Carabidae: Lachnophorini).

A new carabid beetle genus, Balligratus gen. nov., belonging to the tribe Lachnophorini, is described. It is geographically restricted to the equatorial Andes, and ecologically linked to the montane pluvial forest ecosystem, at elevations ranging from 1,200 to 3,600 m. As other carabid lineages that have radiated in such environments, Balligratus gen. nov. is a wingless clade, characterized by the loss of flight wings associated with metathoracic reduction, constriction of the elytral base, and reduced eye size. This evolution is unique among Lachnophorini. Four new species are described, all of them from Ecuador: Balligratus brevis sp. nov., Balligratus globosus sp. nov., Balligratus gracilis sp. nov. and Balligratus humerangulus sp. nov.

Sierra Nevada (Granada, Spain): a high-altitude biogeographical crossroads for millipedes (Diplopoda), with first data on its MSS fauna and description of a new species of the genus Ceratosphys Ribaut, 1920 (Chordeumatida: Opisthocheiridae).

Millipedes (Diplopoda), with a few notable exceptions, are poor dispersers, showing a very high degree of endemicity, not the least in mountains. The first samplings of the Mesovoid Shallow Substratum (MSS) of the higher altitudes of the Sierra Nevada Mountains (Baetic System, Southern Spain) have led to the discovery of a high number of millipedes, each of the species present showing a different degree of establishment in this subterranean environment. An update of the knowledge on the millipedes of this region, the first data of the millipede communities in the MSS and the description of Ceratosphys cryodeserti Gilgado, Mauriès & Enghoff n. sp. are here provided, as well as the first data on the humidity and temperature fluctuations in the MSS of this high mountain. The new species is similar to other Baetico-Riffan species, while the only previously known congener from the region, C. soutadei Mauriès, 1969, has more similarities to certain Pyrenean species. Biogeographical relationships of all the captured species are also discussed.

Fossil carabids from Baltic amber--III--Tarsitachys bilobus Erwin, 1971 an interesting fossil ground beetle from Baltic amber (Coleoptera: Carabidae: Trechinae): Redescription and comments on its taxonomic placement.

Tarsitachys bilobus (Coleoptera, Carabidae) is a fossil species described by Erwin from Baltic amber. Its description was based on only one known specimen, and thus, part of its anatomical structures were unknown as they were poorly preserved in the Holotype. In this paper we complete the description with a second specimen. A new placement among Tachyina and a new status for the genus are proposed.

A new fossil species of the genus Coptodera Dejean, 1825 (Coleoptera: Carabidae: Lebiinae) from Baltic amber.

In this paper a new species of fossil ground-beetle, Coptodera elektra n. sp. (Coleoptera: Carabidae) preserved in a piece of Baltic amber (Eocene) is described and the paleobiology of the species is studied. This new species represents the first known fossil record for the genus, as well as the first record of its presence in Europe.

The hypogean Iberian genus Typhlopsychrosoma Mauriès, 1982 (Diplopoda, Chordeumatida, Vandeleumatidae): distribution map, key to species, first record in a Mesovoid Shallow Substratum (MSS) and detailed iconography of T. baeticaense (Mauriès, 2013).

The troglobiont millipede Typhlopsychrosoma baeticaense (Mauriès, 2013) is recorded in the Mesovoid Shallow Substratum (MSS) of two screes in the Aitana and Bernia mountains (Eastern Iberian Peninsula), far away from its known distribution area. A detailed Scanning Electron Microscopy iconography provides additional information on gonopod morphology, as well as other details such as the inconspicuous evaginations of the cuticle at the place of the eyes in the anophthalmous specimens. We present an updated distribution map and a key to species of the genus, with illustrations of the gonopods of all species described so far. The implications of the appearance of this hypogean species in an MSS are discussed.

Intra- and inter-population polymorphism in Coletinia maggii (Grassi, 1887) (Zygentoma: Nicoletiidae), an inhabitant of soil, mesovoid shallow substratum (MSS) and caves--A challenge for the strict classification of subterranean fauna?

New locations of Coletinia maggii (Grassi, 1887) have been discovered in the center of the Iberian Peninsula in different types of subterranean environments, such as a stony layer in the subsoil of an alluvial plain, an alluvial Mesovoid Shallow Substratum or Milieu Souterrain Superficiel (MSS) and a gypsum cave. This is the first record of both an alluvial MSS in the center of the Iberian Peninsula and of a subterranean species living in it. The high number of specimens captured allowed the first detailed study of the morphological intra- and inter-population variations of this species. The implications of its presence in these different environments, its wide distribution area across Europe, and the relevance of the morphological variation in the characters for the taxonomy of this species are discussed. Based on the results, Coletinia hernandoi Molero, Bach & Gaju, 2013 is proposed as a new synonym of C. maggii.

Subterranean ants: the case of Aphaenogaster cardenai (Hymenoptera: Formicidae).

Recently, a series of systematized studies of the Milieu Souterrain Superficiel (MSS) are being carried in several enclaves of the Iberian Peninsula, which have entailed the finding of the enigmatic ant Aphaenogaster cardenai Espadaler, 1981, hitherto considered as hypogean, in a mountain range far away from its known distribution area. Its ecological role and its possible area of distribution are discussed due to this finding, as well as its known morphology, distribution, habitat use, flight ability of the sexual forms, and moment of activity. This enabled reviewing and discussing the actual knowledge on the possible adaptations and exaptations of the Formicidae to the subterranean environments in wide sense and concretely to the MSS. According to all above, ants might adapt to the deepest hypogean environments by means of changes in their social structure, but without those changes, the MSS would be their last frontier in their process of colonization of hypogean environments.

A new species of Duvalius from world's deepest cave (Coleoptera: Carabidae).

The new hypogean ground beetle, Duvalius abyssimus n. sp., from Krubera-Voronja, world's deepest cave (Arabika massif, Western Caucasus) is described and illustrated. Diagnostic morphological characters of the imago, male and female genitalia are provided. Its relations with other Duvalius Delarouzée species from the Western Caucasus geographic area are discussed. An updated overview of the biocoenosis of its peculiar habitat is made.

A new hypogean Trechus Clairville (Coleoptera, Carabidae, Trechini) discovered in a non-calcareous Superficial Subterranean Habitat of the Iberian System (Central Spain).

A new hypogean species of Trechus Clairville, Trechus arrecheai sp. nov., is described from the Iberian Peninsula. It was captured by subterranean pitfall traps in a non-calcareous Superficial Subterranean Habitat from the Moncayo Massif (Zaragoza, Spain). Data on the accompanying fauna are provided and the biogeographical implications of this discovery are discussed. A synthesis of the data about the known distribution of the Trechus angusticollis species group is provided.

The "Alluvial Mesovoid Shallow Substratum", a new subterranean habitat.

In this paper we describe a new type of subterranean habitat associated with dry watercourses in the Eastern Iberian Peninsula, the "Alluvial Mesovoid Shallow Substratum" (alluvial MSS). Historical observations and data from field sampling specially designed to study MSS fauna in the streambeds of temporary watercourses support the description of this new habitat. To conduct the sampling, 16 subterranean sampling devices were placed in a region of Eastern Spain. The traps were operated for 12 months and temperature and relative humidity data were recorded to characterise the habitat. A large number of species was captured, many of which belonged to the arthropod group, with marked hygrophilous, geophilic, lucifugous and mesothermal habits. In addition, there was also a substantial number of species showing markedly ripicolous traits. The results confirm that the network of spaces which forms in alluvial deposits of temporary watercourses merits the category of habitat, and here we propose the name of "alluvial MSS". The "alluvial MSS" may be covered or not by a layer of soil, is extremely damp, provides a buffer against above ground temperatures and is aphotic. In addition, compared to other types of MSS, it is a very unstable habitat. It is possible that the "alluvial MSS" may be found in other areas of the world with strongly seasonal climatic regimes, and could play an important role as a biogeographic corridor and as a refuge from climatic changes.

A new mute species of the genus Nemobius Serville (Orthoptera, Gryllidae, Nemobiinae) discovered in colluvial, stony debris in the Iberian Peninsula: A biological, phenological and biometric study.

Sampling of a Mesovoid Shallow Substratum (MSS) of a scree in the Guadarrama mountains (Madrid, Spain) revealed a population of crickets of the genus Nemobius Serville. A detailed morphological study revealed that the cricket was a new species, Nemobius interstitialis sp. nov., which is principally characterized by the absence of a tympanum in the outer margin of the foreleg tibiae and a peculiar design of venation of the forewing of the male. Sampling of this environment over 1 year using surface and MSS pitfall traps, set at a depth of one meter, allowed study of population dynamics. A population maximum is attained in August. Abiotic (temperature and humidity) and biotic (accompanying fauna) data are given to contextualize the habitat of this new species.

Oldest true orb-weaving spider (Araneae: Araneidae).

The aerial orb web woven by spiders of the family Araneidae typifies these organisms to laypersons and scientists alike. Here we describe the oldest fossil species of this family, which is preserved in amber from Alava, Spain and represents the first record of Araneidae from the Lower Cretaceous. The fossils provide direct evidence that all three major orb web weaving families: Araneidae, Tetragnathidae and Uloboridae had evolved by this time, confirming the antiquity of the use of this remarkable structure as a prey capture strategy by spiders. Given the complex and stereotyped movements that all orb weavers use to construct their webs, there is little question regarding their common origin, which must have occurred in the Jurassic or earlier. Thus, various forms of this formidable prey capture mechanism were already in place by the time of the explosive Cretaceous co-radiation of angiosperms and their flying insect pollinators. This permitted a similar co-radiation of spider predators with their flying insect prey, presumably without the need for a 'catch-up lag phase' for the spiders.