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The tropical, dry deciduous forests of Chandrapur district provide a wide variety of natural ecosystems to the spider species, leading to spider diversity and abundance. Hence the spiders can be grouped into various ecological guilds, based on the foraging mode as orb weavers, space web builders, sheet web builders, ambushers, ground runners, foliage runners, stalkers etc. The present investigation, therefore, has an interdisciplinary approach that will undertake a comprehensive and holistic study of spider diversity along with the plant diversity. Well established sampling protocols for spider collections were adapted in different selected sampling plots from Chandrapur district. The present study reveals the occurrence of 21 different families, 57 genera and 90 species. Out of total spider species recorded, about 43% were found orb weaver, 17% stalker, 14% ground runner, 13% ambusher, 8% foliage runner, 3% space web builder and 2% were sheet web builder. Occurrence of high number of Araneids could be due to mixed vegetation of the forest which provides enough space to build web of different size and protection from their predators. The forest is dry deciduous and rich in shrubs as understory habitats resulting into more number of Salticides and Lycocides which are stalker in guild. Moderate numbers of Thomicides found in this region is due to availability of flowering plants with deep vegetation in forest area. [ABSTRACT FROM AUTHOR]

Background: The theridiid spider genus Stemmops O. Pickard-Cambridge, 1894 includes 27 extant species and is distributed in America (23 spp.) and Asia (4 spp.). Three species, S. forcipus Zhu, 1998 (♂♀), S. nigrabdomenus Zhu, 1998 (♂) and S. nipponicus Yaginuma, 1969 (♂♀), are currently known from China. New information: Two new species of Stemmops are described from China: S. atratus sp. n. (♀, Jiangsu, Zhejiang) and S. lini sp. n. (♂♀, Fujian, Zhejiang). In addition, the previously unknown female of S. nigrabdomenus Zhu, 1998 is described. Photos and morphological descriptions are provided. [ABSTRACT FROM AUTHOR]

Background: Ischnothyreus Simon, 1893 is one of the most speciose genera of Oonopidae, with 124 extant species mainly distributed in the Old World. Currently, 27 species are known in China. New information: A new species, Ischnothyreus ruyuanensis Tong, sp. n., is described from Guangdong Province, China. Morphological description and illustrations are provided. [ABSTRACT FROM AUTHOR]

Haplocosmia Schmidt & von Wirth, 1996 is a small genus distributed in the Himalayas that includes two species. This genus has not been found in China (Li et al. 2021, Yao et al. 2021, Zhao et al. 2022). [ABSTRACT FROM AUTHOR]

A Linyphiidae spiders Uralophantesponticus sp. n. from Ukraine (Kherson, Sumy, Luhansk Regions) and Russia (Penza Region), differing from U. troitskensis Esyunin, 1992 from the Southern Urals by the male palp parts and female epigynum, is described. [ABSTRACT FROM AUTHOR]

Leptonetela turcica sp. n. is described and illustrated based on material collected in the Kahramanmaraç Province of Turkey. Differences between the new species and the closely related species are discussed. [ABSTRACT FROM AUTHOR]

Spiders are among the most ubiquitous arthropods that can dwell on diverse habitats, which include small-scale urban green spaces (UGS). To promote urban biodiversity, we assessed the awareness of a local community situated within UGS in Davao, Philippines about the ecological roles of spiders. Data were obtained by administering survey questionnaires to 80 households using convenience sampling. The survey revealed that the local community is knowledgeable on the occurrence of spiders in their area (97.5%), in which they are mostly acquainted with spiders of Pisauridae (25%) and Araneidae (20.3%). Also, the community has recognized the important ecological roles of spiders, in which they mostly acknowledged them as a significant source of food for other organisms (71.62%). However, a high proportion of respondents also recognized the socio-economic benefits of spiders through spider wrestling (60.81%). Henceforth, the ecological roles of spiders could be subjugated as spider wrestling is practiced in the local community, which could be a possible threat to the spider population. Thus, we highly suggest to involve concerned local communities in urban biodiversity management for the conservation of spiders in the Philippines, which is at risk due to its perceived socio-economic benefits. [ABSTRACT FROM AUTHOR]

Observations of the biology of the spider genus Corasoides Butler, 1929 from Australia and New Guinea are presented from a study of both captive and field individuals. Details are provided on habitat, population density, web building, prey capture, courtship and mating, eggs, life cycle, parasites, parasitoids and predators. A new purpose (web protection from falling debris) is proposed for the overhead labyrinth of the web. [ABSTRACT FROM AUTHOR]

The genus Ischnothyreus Simon, 1893 is one of the most speciose genera of Oonopidae, with 114 extant species mainly distributed in the Old World. Currently, 16 species have been recorded in China. [ABSTRACT FROM AUTHOR]

Two exotic spider species are reported for the first time in Argentina: Ozyptila praticola (C.L. Koch) (Thomisidae) and Microctenonyx subitaneus (O. Pickard-Cambridge) (Linyphiidae), being the former the first record from the southern hemisphere. The specimens were found in the leaf litter and under tree barks of modified environments in three localities in the southeast coast of Buenos Aires province. We propose the monitoring and study of the ecology of these new spider populations in order to elucidate potential risk for the local fauna. [ABSTRACT FROM AUTHOR]

Present work deals with HPLC method for determination of amino acid and study chemical composition of spider silk, this specimens were collected from variant regions in Baghdad all spiders produce silk and most produce multiple types of silk fibers. Silks are typically semicrystal line fibers that among the strongest, toughest and stretchiest biological fibers spider’s silk is made up of protein is termed a spidroin, for spider fibroin. Spidroins consist of 100–400 amino acids major amino acids in the silk proteins are alanine 24.3% and glycine 30.2% Serine and proline are also present in significant quantities in some types of silk. Glycine is rich regions give spider silk elasticity forming a morphous areas in structure, Alanine is rich regions link together form crystall ineare as that give spider silk its strength the exact composition of these proteins depends on factors including species and diet, the remaining components are mostly glutamine, serine, leucine, valine, proline, tyrosine and arginine the function of silk is prey capture webs provides a crucial link between the molecular biology of silk and spider ecology. Web building ability generally the spiders are considered as weavers or non-weavers, the weavers make the snares to trap insects for food in family Pholcidae, while the non-weavers hunt the prey by chasing in families Lycosidae, Gnaphosidae, Salticidae and Oxyopidae in this research, we study the chemical composition of spiders silk and the designing web patterns are Orb web, Horizontal webs and Single line webs, Sheet web, Irregular webs, wooly webs, Funnel webs, the orb web and sheet web so in this research, we need to know more about the spider silk and the spider webs. [ABSTRACT FROM AUTHOR]

Background The semideciduous Atlantic Forest is one of the most diverse ecosystems in the world with a great diversity of spiders. Most spider-related studies in this ecosystem focused on species richness and composition; however, little is known about their trait diversity (including morphological, ecological and/or physiological traits). Two main datasets were compiled to generate a complete record of spider traits for this ecosystem. New information Here, we present two datasets about 259 species of spiders from the semideciduous Atlantic Forest of Argentina. The trait data set compiled information of morphological and ecological traits such as body size, femur length, ocular distance, foraging strategy, prey range, circadian activity and stratum preference; traits were assessed by species considering sexual dimorphism. The second dataset included information about phenology (season when spiders were collected), number of individuals assessed by species and presence/absence of spiders in the different sample sites. This dataset has high potential to help researchers in recording the state of a component of biodiversity (functional) and contributes with the study of ecosystem services and species conservation. [ABSTRACT FROM AUTHOR]

In June 2019, an ecology field course of the University of Helsinki was held at Lammi Biological Station, Southern Finland. Within this course, the students familiarised themselves with field work and identification of spiders and explored the diversity of species in the area. Three sampling plots were chosen, one in grassland and two in boreal forest, to demonstrate the sampling techniques and, by applying a standardised protocol (COBRA), contribute to a global spider biodiversity project. New information The collected samples contained a total of 3445 spiders, of which 1956 (57%) were adult. Only adult spiders were accounted for in the inventory due to the impossibility of identification of juveniles. A total of 115 species belonging to 17 families were identified, of which the majority (58 species, 50%) were Linyphiidae. Lycosidae and Theridiidae both had 11 species (10%) and all the other families had seven or fewer species. Linyphiidae were also dominant in terms of adult individuals captured, with 756 (39%), followed by 705 (36%) Lycosidae. Other families with more than 100 individuals were Thomisidae (196, 10%) and Tetragnathidae (102, 5%). The most abundant species were the lycosids Pardosa fulvipes (362, 19%) and Pardosa riparia (290, 15%) and the linyphiid Neriene peltata (123, 6%). [ABSTRACT FROM AUTHOR]

Background Spiders (Arachnida: Araneae) are widespread in subterranean ecosystems worldwide and represent an important component of subterranean trophic webs. Yet, global-scale diversity patterns of subterranean spiders are still mostly unknown. In the frame of the CAWEB project, a European joint network of cave arachnologists, we collected data on cavedwelling spider communities across Europe in order to explore their continental diversity patterns. Two main datasets were compiled: one listing all subterranean spider species recorded in numerous subterranean localities across Europe and another with high resolution data about the subterranean habitat in which they were collected. From these two datasets, we further generated a third dataset with individual geo-referenced occurrence records for all these species. New information Data from 475 geo-referenced subterranean localities (caves, mines and other artificial subterranean sites, interstitial habitats) are herein made available. For each subterranean locality, information about the composition of the spider community is provided, along with local geomorphological and habitat features. Altogether, these communities account for > 300 unique taxonomic entities and 2,091 unique geo-referenced occurrence records, that are made available via the Global Biodiversity Information Facility (GBIF) (Mammola and Cardoso 2019). This dataset is unique in that it covers both a large geographic extent (from 35° south to 67° north) and contains high-resolution local data on geomorphological and habitat features. Given that this kind of high-resolution data are rarely associated with broad-scale datasets used in macroecology, this dataset has high potential for helping researchers in tackling a range of biogeographical and macroecological questions, not necessarily uniquely related to arachnology or subterranean biology. [ABSTRACT FROM AUTHOR]

Background The Iberian Peninsula is a diverse region that contains several different bioclimatic areas within one confined space, leading to high biodiversity. Portugal distinguishes itself in this regard by having a high count of spider species (829) and a remarkable number of endemic spider species (42) for its size (approximately 88,890 km2). However, only one non-endemic species (Macrothele calpeiana) is currently protected by the Natura 2000 network and no endemic spider species (aside from Anapistula ataecina) has been assessed according to the IUCN Red List criteria. The objective of this paper is to assess all non-assessed endemic species (41) as well as M. calpeiana. New information The 43 assessed species belong to 15 families, the richest being Zodariidae, Dysderidae, Linyphiidae and Gnaphosidae. In general and despite the lack of information on more than half the species, general patterns and trends could be found. Only 18 species (including M. calpeiana and A. ataecina) had enough data to allow their EOO (extent of occurrence) and AOO (area of occurrence) to be quantified. Of these, we modelled the distribution of 14 epigean species, eight of which were found to be widespread. The remaining six fulfilled at least one of the criteria for threatened species. Four species are troglobiont, all of which meet the EOO and AOO thresholds for threatened species. The remaining 25 Portuguese endemics had no reliable information on their range. Only nine species out of the 43 are estimated to be in decline and 11 are stable, with the majority of species having no information on trends (23 species). Forest areas, sand dunes, shrublands and caves host the majority of species. As such, the threats to Portuguese endemics reflect the diversity of habitats they occupy. Urbanisation and climate change seem to be the most important threats to these species, although other factors are also important and represented across the data. A considerable proportion of the currently known Portuguese endemic species can be found in national protected areas, with higher prominence to the Serras de Aire e Candeeiros, Douro Internacional, Vale do Guadiana, Sudoeste Alentejano e Costa Vicentina and Arrábida Natural Parks. These correspond mostly to areas that have been particularly well sampled during the last two decades. [ABSTRACT FROM AUTHOR]

Highlights • Searsia lancea litter assemblages were studied in South African grassland habitats. • Assemblages are more similar in grasslands and hillsides versus riparian woodlands. • There is evidence of disturbance in grasslands and riparian woodlands. • Habitat significantly influence abundance, species richness and assemblages. • Position and orientation only affected assemblage structure significantly. Abstract Spiders are a prominent component of leaf litter assemblages, where they function as critical predators of other invertebrates. We investigated the influence of habitat, cardinal directions and position on Searsia lancea litter-dwelling spider assemblages in central South Africa. A total of 1521 spiders were collected, representing 27 families and 77 species. Species richness, abundance and coverage per tree were highest in the grassland, followed by the hillside and riparian habitats. Neither of the finer scale filters, direction nor position, had significant effects on species richness or abundance, although there was weak evidence for an increase in spider abundance toward the periphery of a tree (p = 0.09) and a decrease in abundance towards the western cardinal direction (p = 0.08). Species composition, though, was significantly affected by habitat (p = 0.001) and direction (p = 0.014), as well as a three way-interaction between habitat, direction and position (p = 0.01). Hillside assemblage structure is intermediate between the other two habitats. Species abundance distributions of all three habitats were multimodal, indicating disturbance. Particularly, the log-series distribution of both the grassland and riparian woodland point to more disturbed assemblages than the hillside (Poisson log-normal distribution). Habitat therefore played a significant role in affecting richness, abundance and assemblage structure (composition and abundance). Although finer scale variables only had a weak effect on abundance, spider assemblages were influenced by direction, particularly for the climatically more variable habitats of the grassland and hillside. The significantly higher evenness and less disturbed nature of the hillside emphasize the conservation significance of this habitat. [ABSTRACT FROM AUTHOR]

Earlier studies emphasized that landscape-level factors were essential in shaping arthropod assemblages of semi-natural grasslands. Recently, several studies demonstrated that local factors were more important than landscape-level factors. We examined the importance of several local and landscape-level factors on spider assemblages using pitfall traps from eight sandy grassland fragments between 2001 and 2003. We tested three hypotheses: (i) species richness decreases with grazing intensity; (ii) species richness increasing with fragment size; (iii) the higher isolation of fragments results in decreasing species richness. We found that species richness of spiders did not depend on the grazing intensity, but there were changes in species composition and abundance of species among the variously grazed fragments. Out of the other two studied local factors (fragment size, and the shape of fragment), only the fragment size was a significant predictor of the diversity of specialist spiders, since the number of these species increased significantly with fragment size. Out of the four investigated landscape-level factors (isolation, total area of croplands in the landscape, total area of forests in the landscape, and landscape diversity), only the isolation was a significant predictor influencing spider diversity. The total number of species, the number of generalist species and the number of hunting species increased significantly with the isolation of fragments. Our results suggest that both local and landscape-level factors are important drivers in maintaining spider diversity in sandy grasslands; therefore, these factors should be considered simultaneously during the restoration and/or management of grasslands. [ABSTRACT FROM AUTHOR]

Dispersal is a key process in metapopulation dynamics and metacommunity assembly as it may be affected by a variety of factors acting at different spatial scales. While dispersal is known to evolve in response to landscape-related selection pressures, local dynamics are merely driven by conditional responses, for instance by habitat quality and density. Local and regional factors are thus expected to impact dispersal, either synergistically or antagonistically. Moreover, such responses do not need to coincide among all life stages because different life stages are expected to incur different costs, either intrinsically due to for instance differences in size or extrinsically because of demographic changes. Our general objective is consequently to test for the likely opposite effects of main factors acting on dispersal, i.e. local density and habitat configuration, at different life-stages in a salt marsh inhabiting spider Pardosa purbeckensis (F.O.P.-Cambridge 1895). Using a combination of both field and laboratory experiments on pre-dispersal behaviour, we demonstrate a significant negative density-dependence for natal dispersal, but no alike effect at the adult stage. No effects of the local habitat structure were detected. Therefore, good mother body condition could be interpreted by juveniles during the phase of maternal care as suitable living conditions, decreasing emigration rate. Although dispersal is known to have a genetic basis, local factors eventually overrule this source of variation. [ABSTRACT FROM AUTHOR]

Representatives of the Southeast Asian pholcid spider genus Uthina Simon, 1893 have been thought to be very homogeneous in their ecology and morphology. The 14 previously known species all inhabit near-ground microhabitats and cave entrances, and range from pale to dark brown in colour. Even their genitalia are partly very similar, with some species pairs being barely distinguishable based on morphological characters. Here we describe three new species from Bali, Java and Sulawesi that represent three further microhabitats and demonstrate considerable ecological and morphological diversity within the genus: U. maya , sp. nov. from Bali is a large dark species on tree trunks; U. hylobatea , sp. nov. from Bali and eastern Java is a pale leaf-dwelling species that exhibits colour dimorphism; and U. mimpi , sp. nov. is a pale troglomorphic species collected in the aphotic zones of two South Sulawesi caves. In addition, we present new data for five previously described species, including ultrastructure, natural history, new records, taxonomic notes and a description of the previously unknown female of Uthina khaosokensis Yao, Li & Jäger, 2014. Molecular data suggest that all previously described species are very closely related to each other (constituting the monophyletic luzonica -group), and that the three new species represent separate clades within the genus. However, the basal trichotomy could not be resolved: U. maya + (U. hylobatea + U. mimpi) + luzonica -group. Spiders in the genus Uthina have been thought to be very homogeneous in their ecology and morphology. Here we describe three new species from Bali, Java, and Sulawesi that demonstrate considerable ecological and morphological diversity within the genus. Molecular data suggest that all previously described species are closely related to each other and that the three new species represent separate clades within the genus. [ABSTRACT FROM AUTHOR]

A new genus, Kachinia Tong & Li, gen. n., including two new species, K. putao Tong & Li, sp. n., and K. mahmolae Tong & Li, sp. n., is described from Myanmar. The new genus belonging to the subfamily Oonopinae Simon, 1890, currently is the only member of the Brignolia-Opopaea clade with leg spines. [ABSTRACT FROM AUTHOR]

Sixteen new species of Pseudopoda Jäger, 2000 (Sparassidae, Heteropodinae) are described. Among them, eight species were collected from China: P. chayuensis Zhao & Li, sp. n. (♂), P. conaensis Zhao & Li, sp. n. (♂), P. medogensis Zhao & Li, sp. n. (♂), P. nyingchiensis Zhao & Li, sp. n. (♂), P. shacunensis Zhao & Li, sp. n. (♂), P. shuo Zhao & Li, sp. n. (♂♀), P. yuanjiangensis Zhao & Li, sp. n. (♀) and P. zixiensis Zhao & Li, sp. n. (♂); seven from Myanmar: P. colubrina Zhao & Li, sp. n. (♂♀), P. daxing Zhao & Li, sp. n. (♂), P. gexiao Zhao & Li, sp. n. (♂), P. putaoensis Zhao & Li, sp. n. (♂), P. subbirmanica Zhao & Li, sp. n. (♂♀), P. titan Zhao & Li, sp. n. (♂♀), P. xia Zhao & Li, sp. n. (♂); and one from Thailand: P. maeklongensis Zhao & Li, sp. n. (♂). A distribution map of the new species is also provided. [ABSTRACT FROM AUTHOR]

1. Although spiders can colonise ecosystems by air, dispersal capabilities differ among spider species. Web‐building spiders are thought to balloon at higher rates than hunting spiders. Spider success in agricultural systems may also depend on habitat preferences. Few studies have examined the success of aerially dispersing spiders in crop systems, and information about the dispersal capabilities of spiders in putative source habitats is limited. 2. Spiders were monitored in the air and on the foliage of vineyards and adjacent oak woodland in order to compare the aerial spider faunas between these disparate habitats and to determine whether highly dispersive species contributed disproportionately to the spider community in vineyards. 3. The results show that most aerially dispersing spiders in both habitats were web‐building dwarf spiders, Erigone spp. (Linyphiidae), although hunting spiders were also well represented in the air, especially in oak woodland. Most woodland spiders in the air appeared to be residents of oak woodland and probably dispersed only short distances. 4. Conversely, only a subset of the aerial spider fauna established in vineyards in high numbers. Spiders that dominated the aerial fauna were under‐represented on vineyard foliage, whereas several hunting spiders dispersed aerially at low rates but dominated vineyard spider composition. 5. These results suggest that aerial dispersal ability may allow spiders to reach crop systems, but that establishment depends on habitat preferences and/or competitive ability. [ABSTRACT FROM AUTHOR]

Sea-level change has been viewed as a primary driver in the formation of biodiversity. Early studies confirmed that Plio–Pleistocene sea-level changes led to the isolation and subsequent genetic differentiation of Southeast (SE) Asian organisms over short geological timescales. However, long-time consequences of sea-level fluctuations remain unclear. Herein, we analyze the evolutionary history of Althepus (spiders) whose distribution encompasses Indo-Burma and the Sunda shelf islands to understand how sea-level changes over shallow and deep timescales effected their history. Our integrative analyses, including phylogeny, divergence times, ancestral area reconstruction and diversification dynamics, reveal an intricate pattern of diversification, probably triggered by sea-level fluctuations during the Paleocene–Eocene and Plio–Pleistocene. The timing of one early divergence between the Indo-Burmese and Sundaic species coincides with late Paleocene and early Eocene high global sea levels, which induced the formation of inland seaways in the Thai-Malay Peninsula. Subsequent lowered sea levels could have provided a land bridge for its dispersal colonization across the Isthmus of Kra. Analyses suggest that Plio–Pleistocene sea-level rises contributed to recent divergence of many species. Thus, our findings cannot reject the hypothesis that sea-level changes during the Paleocene–Eocene and Plio–Pleistocene played a major role in generating biodiversity in SE Asia; sea-level changes can act as “species pumps”. [ABSTRACT FROM AUTHOR]

Spiders of the nemesiid mygalomorph subfamily Anaminae are common in the Australasian region from rainforests to deserts. Using specimens from all 12 named genera, we evaluated anamine phylogeny and classification using a multi-locus molecular dataset. We combined newly obtained 18S and 28S ribosomal RNA and elongation factor 1 gamma (EF-1γ) sequences with an existing published dataset and further analysed an expanded mitochondrial (12S rRNA, 16S rRNA, COI) and nuclear (18S rRNA, 28S rRNA, Histone H3, EF-1γ) dataset. The resulting trees showed that most Australasian Anaminae formed a monophyletic group congruent with the tribe Anamini, but that the genus Stanwellia grouped with non-Australian exemplars. Molecular divergence dating revealed that the major Australian radiation of Anamini occurred during the Miocene, with multiple independent incursions from temperate habitats into the arid zone. New Zealand Stanwellia nested within a clade including otherwise Australian taxa, with divergence estimates for the entire genus between 8 and 38 Mya, suggesting that their presence in New Zealand is the result of transoceanic dispersal, rather than continental vicariance. The molecular phylogenies were reconciled with morphological data and used to stabilize the generic classification by recognizing Stanwellia, plus nine genera of Anamini, all of which are newly diagnosed. [ABSTRACT FROM AUTHOR]

Agricultural intensification has resulted in major losses of biodiversity due to landscape homogenization and an increasing use of agrochemicals. It has often been assumed that associated changes in environmental conditions are impacting composition and diversity of two main ground-dwelling generalist predator taxa, carabid beetles and epigaeic spiders, in similar ways. Here, we test how variations in environmental conditions at local scales (plant diversity and total soil nitrogen, N tot ) and landscape-scale (mean patch size) affect species composition, richness and abundance of ground beetles and epigaeic spiders in semi-natural and cultivated habitats of an agricultural landscape. We specifically test the hypotheses that both taxa are more diverse in semi-natural than cultivated habitats, but that due to their weaker dispersal ability, ground beetles are more strongly linked to local factors than spiders. Our results indicate that in our study area, carabid diversity shows no significant difference between semi-natural habitats and cropland, while spider abundance is significantly enhanced in semi-natural habitats. N tot significantly affected carabid species richness and abundance, but had a limited influence on spider abundances. The species composition of both carabids and spiders was influenced by plant diversity, while N tot played a significant role in determining spider assemblages but not carabid composition. There was no significant effect of the mean patch size in the surroundings landscape on either spider or carabid species. Nonetheless, in landscapes with small patch sizes, spider abundance decreased with increasing N tot , while in landscapes with large sized patches, this relationship was reversed. The differences in responses of these taxa to local and landscape-scale environmental factors suggests that scale- and taxon-specific targets need to be established to improve the efficiency of measures aimed at enhancing ecosystem services provisions by these key pest control agents. [ABSTRACT FROM AUTHOR]

Abstract Arthropod communities in fragmented agricultural landscapes depend on local processes and the interactions between communities in the habitat islands. We aimed to study metacommunity structure of spiders, a group that is known for high dispersal power, local niche partitioning and for engaging in species interactions. While living in fragmented habitats could lead to nestedness, other ecological traits of spiders might equally lead to patterns dominated either by species interactions or habitat filtering. We asked, which community pattern will prevail in a typical agricultural landscape with isolated patches of semi-natural habitats. Such a situation was studied by sampling spiders in 28 grassland locations in a Hungarian agricultural landscape. We used the elements of metacommunity structure (EMS) framework to distinguish between alternative patterns that reveal community organization. The EMS analysis indicated coherent species ranges, high turnover and boundary clumping, suggesting Clementsian community organization. The greatest variation in species composition was explained by local habitat characteristics, indicating habitat filtering. The influence of dispersal could be detected by the significant effect of landscape composition, which was strongest at 500 m. We conclude that dispersal allows spiders to respond coherently to the environment, creating similar communities in similar habitats. Consistent habitat differences, such as species rich versus species poor vegetation, lead to recognisably different, recurrent communities. These characteristics make spiders a predictable and diverse source of natural enemies in agricultural landscapes. Sensitivity to habitat composition at medium distances warns us that landscape homogenization may alter these metacommunity processes. [ABSTRACT FROM AUTHOR]

Abstract: We provide the first overview on spiders living in subterranean habitats in Europe, including the first European subterranean spider checklist. In Europe, there are 486 spider species known to dwell in caves and other subterranean habitats, distributed across 22 families. Despite a few species being able to colonize caves across the whole continent, approximately 90% of the species show a restricted distribution, occurring exclusively in one or two countries. From a biogeographic perspective, southern Europe emerges as the main hot spot of subterranean spider diversity, showing the highest richness of endemic species. Compared to other temperate regions of the world, some families appear to be well represented and other poorly represented (or lacking) in European subterranean habitats. Overall, it appears that the taxonomical knowledge on subterranean spiders in Europe is sufficient, but not evenly distributed. As this checklist represents a useful baseline for advances in this field, we point out specific areas of interest for future research. [ABSTRACT FROM AUTHOR]

The effect of environmental conditions on reproductive traits in spiders is not completely understood. We studied the trade-off between the egg number and egg size of a common spider species along an elevational gradient in Norway. Life history theory predicts that egg size should decrease and clutch size increase as temperatures rise. In 2006, 2010, and 2014, female lycosid spiders (Pardosa palustris) carrying first egg sacs were hand sampled from 690 to 1460 m above sea level (a.s.l.). The eggs were counted, and the body and egg sizes for each female were individually estimated using digital photography. An analysis of covariance was performed using linear mixed-effects models to test for trade-off differences between sampling years, and along the elevational gradient. Unexpectedly, the egg size versus number trade-off was consistent along the elevational gradient, and thus appeared to be independent of elevation-induced temperature changes. However, this trade-off varied considerably between years. Egg-size variations in relation to body size appeared to be independent of year and did not vary along the elevational gradient. Our results revealed that the trade-off between egg number and egg size does not always hold and might be more plastic than assumed. This suggests that P. palustris, which has a broad habitat niche and a wide geographic distribution, will easily cope with temperature-regime shifts in cold environments. Consequently, this might lead to advantages regarding the offspring survival rate relative to coexisting species, and thus to changes in the terrestrial arthropod community of alpine-tundra ecosystems. [ABSTRACT FROM AUTHOR]

Spiders of the genus Althepus Thorell, 1898 are found throughout Southeast Asia, notable for their long walking legs. Ten new species are reported in this paper from China, Indonesia, Laos and Myanmar: A. chengmenensis Li & Li, sp. n. (♂♀), A. cheni Li & Li, sp. n. (♂♀), A. gouci Li & Li, sp. n. (♂♀), A. hongguangi Li & Li, sp. n. (♂♀), A. phousalao Li & Li, sp. n. (♂♀), A. qianhuang Li & Li, sp. n. (♂♀), A. qingyuani Li & Li, sp. n. (♀), A. sepakuensis Li & Li, sp. n. (♂♀), A. xuae Li & Li, sp. n. (♂♀) and A. yizhuang Li & Li, sp. n. (♂♀). These species were found in cave entrances and among tree-buttresses, indicating the spiders have a preference for dark and moist environments. All types are deposited in the Institute of Zoology, Chinese Academy of Sciences in Beijing, China (IZCAS). [ABSTRACT FROM AUTHOR]

Abstract: Calcareous grassland is one of the most species rich and diverse habitats within Europe, but has faced decline due to agricultural intensification and abandonment. In recent years, conservation organisations have altered grazing practices in an attempt to maintain floristic components. However, there has been little consideration of the effects of changes in grazing practices on invertebrates. This study determines the impacts of commonly used grazing practices in upland calcareous grasslands on spiders in relation to vegetation structural complexity. Typical grazing management regimes were examined in three regions of upland calcareous grassland in Britain. Spiders were sampled from April to August 2014 and vegetation structural complexity was recorded in 2 × 2 m quadrats paired with pitfall traps sequentially throughout the sample period. There were three distinct spider assemblages among the grazing regimes; ungrazed, heavy sheep grazed and one shared between cattle and light sheep (which had a comparable grazing intensity). The distinct spider assemblages among grazing regimes can be attributed to the interaction of grazing and habitat structure. Increased vegetation structural complexity in ungrazed regimes resulted in an assemblage dominated by ‘sheet web weavers’ (dominated by Linyphiidae). In contrast, reduced vegetation structural complexity and homogeneity in heavy sheep grazing resulted in an assemblage dominated by ‘other hunters’ (including Oedothorax and Erigone genera). Grazing regime alters vegetation structural complexity and is important in supporting distinct spider assemblages. This research indicates that low intensity conservation grazing regimes, in addition to no grazing, should be promoted across upland calcareous grassland landscapes to maintain heterogeneity. [ABSTRACT FROM AUTHOR]

Wolf spiders (Araneae: Lycosidae) are abundant ground predators in cotton fields that can provide important pest management services. These spiders can kill and consume larvae of the cotton bollworm Helicoverpa spp. (Lepidoptera: Noctuidae) that survive foraging on Bt cotton and descend from the plant to pupate in the soil. To determine predation frequency by wolf spiders in a Bt cotton field, we indirectly assessed predation using Helicoverpa spp. larvae marked with rabbit immunoglobulin G (IgG; “immunomarking”), and carried out capture-mark-recapture surveys to assess the likelihood of recapturing spiders. A laboratory feeding study with IgG-marked larva demonstrated that IgG is readily detected in spiders for up to 72 h after feeding. Following the release of IgG-marked larvae in a cotton field edge, 2.1% of spiders collected tested positive for the presence of IgG, providing indirect evidence of predation. A capture-mark-recapture survey revealed that spiders had opportunity to encounter IgG-marked larvae released along field edges, but only 6.7% of the spiders were recaptured, likely reflecting high spider mobility. In field feeding arenas, all three commonly encountered wolf spider species ( Tasmanicosa leuckartii, Hogna crispipes, Hogna kuyani ) ate Helicoverpa spp. larvae. These studies suggest that the low likelihood of spider recapture, and not prey rejection, is the most likely explanation for the low proportion of field-collected spiders testing positive for IgG marked prey remains, and that the frequency of IgG detection in spiders likely underestimated the frequency of predation events. We conclude that use of prey immunomarking together with capture-mark-recapture surveys can provide a powerful tool for assessing the effect of a predator on a prey species under field conditions. [ABSTRACT FROM AUTHOR]

The physical mechanism of aerial dispersal of spiders, “ballooning behavior,” is still unclear because of the lack of serious scientific observations and experiments. Therefore, as a first step in clarifying the phenomenon, we studied the ballooning behavior of relatively large spiders (heavier than 5 mg) in nature. Additional wind tunnel tests to identify ballooning silks were implemented in the laboratory. From our observation, it seems obvious that spiders actively evaluate the condition of the wind with their front leg (leg I) and wait for the preferable wind condition for their ballooning takeoff. In the wind tunnel tests, as-yet-unknown physical properties of ballooning fibers (length, thickness, and number of fibers) were identified. Large spiders, 16–20 mg Xysticus spp., spun 50–60 nanoscale fibers, with a diameter of 121–323 nm. The length of these threads was 3.22 ± 1.31 m (N = 22). These physical properties of ballooning fibers can explain the ballooning of large spiders with relatively light updrafts, 0.1–0.5 m s−1, which exist in a light breeze of 1.5–3.3 m s−1. Additionally, in line with previous research on turbulence in atmospheric boundary layers and from our wind measurements, it is hypothesized that spiders use the ascending air current for their aerial dispersal, the “ejection” regime, which is induced by hairpin vortices in the atmospheric boundary layer turbulence. This regime is highly correlated with lower wind speeds. This coincides well with the fact that spiders usually balloon when the wind speed is lower than 3 m s−1. [ABSTRACT FROM AUTHOR]

This is the first study about trophic traits of Grammostola vachoni , a threatened theraphosid spider endemic to the mountain systems of central Argentina. Four prey types were used in experiments: crickets, cockroaches, beetle larvae and adult beetles. Grammostola vachoni was observed to eat at a rate of about once every 11 days, with the mean total number of prey consumed per spider during the experimental period being 2.7. Latency to the first attack was similar for crickets, cockroaches and beetle larvae, but was shorter for adult beetles. Feeding time was significantly longer for crickets and beetle larvae. Mass gain was significantly different among prey types. Feeding effectiveness and ingestion rate were significantly higher for crickets. A significant positive correlation for feeding effectiveness and ingestion rate with prey mass and the initial spider mass was also found. We studied the feeding parameters of Grammostola vachoni , a threatened Theraphosidae spider, endemic to the mountain systems of central Argentina. The knowledge of trophic traits is important for understanding animal ecology, and the contribution to the ecosystem that G. vachoni has as a predator, combined with potential threats of habitat make it necessary to obtain biological information to support its conservation. Therefore, this study contributes to the basic knowledge of the ecology of this tarantula. [ABSTRACT FROM AUTHOR]

Abstract: Most spiders are natural enemies of pests, and it is beneficial for the biological control of pests to learn the relationships between symbionts and their spider hosts. Research on the bacterial communities of insects has been conducted recently, but only a few studies have addressed the bacterial communities of spiders. To obtain a complete overview of the microbial communities of spiders, we examined eight species of spider (Pirata subpiraticus, Agelena difficilis, Artema atlanta, Nurscia albofasciata, Agelena labyrinthica, Ummeliata insecticeps, Dictis striatipes, and Hylyphantes graminicola) with high‐throughput sequencing based on the V3 and V4 regions of the 16S rRNA gene. The bacterial communities of the spider samples were dominated by five types of endosymbionts, Wolbachia, Cardinium, Rickettsia, Spiroplasma, and Rickettsiella. The dominant OTUs (operational taxonomic units) from each of the five endosymbionts were analyzed, and the results showed that different spider species were usually dominated by special OTUs. In addition to endosymbionts, Pseudomonas, Sphingomonas, Acinetobacter, Novosphingobium, Aquabacterium, Methylobacterium, Brevundimonas, Rhizobium, Bradyrhizobium, Citrobacter, Arthrobacter, Pseudonocardia, Microbacterium, Lactobacillus, and Lactococcus were detected in spider samples in our study. Moreover, the abundance of Sphingomonas, Methylobacterium, Brevundimonas, and Rhizobium in the spider D. striatipes was significantly higher (p < .05) than the bacterial abundance of these species in seven other spider species. These findings suggest that same as in insects, co‐infection of multiple types of endosymbionts is common in the hosts of the Araneae order, and other bacterial taxa also exist in spiders besides the endosymbionts. [ABSTRACT FROM AUTHOR]

Most spiders are euryphagous predators. However, there are also a few species with a stenophagous diet, foraging on only a single prey taxon. This strategy could have resulted from ecological opportunity or from evolutionary specialization, which is typical for phylogenetically advanced species. In Zodariidae, myrmecophagy is considered a derived trophic strategy. Therefore, the main objective of this study was to investigate the trophic ecology of Leprolochus birabeni (Zodariidae), whose rather basal position in the phylogeny predicts euryphagy. We studied the realized niche (potential and actual prey) and the fundamental niche (capture success), capture efficiency and behavioural adaptations in males and females of this species. Observations in nature revealed a narrow trophic niche composed only of ants. The most frequently captured prey in the field were two species of Acromyrmex ants, and this was also confirmed in the DNA gut content analysis. Acceptance experiments revealed that both females and males refused to catch prey other than ants. We found nocturnal activity in L. birabeni to be correlated significantly with the activity of one of their preferred prey, Acromyrmex lobicornis. In conclusion, our results show that L. birabeni is a stenophagous ant-eating specialist with a high preference for Acromyrmex ants. [ABSTRACT FROM AUTHOR]

The main objective of this paper is to report habitat occupancy, naturalness status and phenology of Urocoras longispinus (Chyzer and Kulczyński 1897), a little-known spider species. Sampling was conducted in Natura 2000 habitats of the Mátra Mountains, and four disturbed mainroad verges in Hungary between 2012 and 2015. We recorded 356 adult specimens active throughout the year, but abundance was highest in autumn. In the Mátra Mountains shrub removal negatively affected the abundance of U. lonsgspinus: the species preferred shaded habitats. The intensity of mowing maintenance caused changes in the species’ abundance in mainroad verges: the number of individual spiders increased as a result of both without maintenance and enhanced maintenance. We conclude that U. longispinus is a stenochronous spider species which lives in both human-disturbed and undisturbed habitats. However, the nature of the disturbance influenced the abundance of this species to varying degrees. [ABSTRACT FROM AUTHOR]

Studies of subterranean habitats in Slovakia revealed two rare linyphiid spider species new to the country, Pseudomaro aenigmaticus Denis, 1966 and Pseudocarorita thaleri (Saaristo, 1971). Pseudomaro aenigmaticus was recorded in the Malé Karpaty Mountains in western Slovakia. A male was captured in the limestone Plavecká Cave and a female was found in a granitoid mesovoid shallow substratum (MSS) in the Jajcajov jarok Valley. One pair of Pseudocarorita thaleri was found in the MSS in the Belinské skaly Nature Monument in the Cerová vrchovina Highland in southern Slovakia. This study also presents the characteristic habitus and habitats of the recorded spiders. [ABSTRACT FROM AUTHOR]

Pholcidae are ubiquitous spiders in tropical and subtropical caves around the globe, yet very little is known about cave-dwelling pholcids beyond what is provided in taxonomic descriptions and faunistic papers. This paper provides a review based on a literature survey and unpublished information, while pointing out potential biases and promising future projects. A total of 473 native (i.e. non-introduced) species of Pholcidae have been collected in about 1000 caves. The large majority of cave-dwelling pholcids are not troglomorphic; a list of 86 troglomorphic species is provided, including 21 eyeless species and 21 species with strongly reduced eyes. Most troglomorphic pholcids are representatives of only two genera: Anopsicus Chamberlin & Ivie, 1938 and Metagonia Simon, 1893. Mexico is by far the richest country in terms of troglomorphic pholcids, followed by several islands and mainland SE Asia. The apparent dominance of Mexico may partly be due to collectors' and taxonomists' biases. Most caves harbor only one pholcid species, but 91 caves harbor two and more species (up to five species). Most troglomorphic pholcids belong to two subfamilies (Modisiminae, Pholcinae), very few belong to Smeringopinae and Arteminae, none to Ninetinae. This is in agreement with the recent finding that within Pholcidae, microhabitat changes in general are concentrated in Modisiminae and Pholcinae. [ABSTRACT FROM AUTHOR]

The genus Islandiana (Araneae, Linyphiidae) was erected by Braendegaard in 1932 and is comprised of 14 species, most of which are native to North America. Herein we add a 15th species, Islandiana lewisi sp. n., from southern Indiana, USA. This species resembles both I. flavoides Ivie, 1965 and I. cavealis Ivie, 1965, the latter of which is geographically-close. [ABSTRACT FROM AUTHOR]

The La Plata River basin comprises the second largest fluvial system in South America and includes the southernmost remains of the 'Atlantic Forest Biodiversity Hotspot'. We used species distribution modelling to evaluate potential effects of climate change on six species of Stenoterommata. Changes in the size of suitable climatic regions and numbers of known occurrence sites were evaluated within the distribution limits of the studied species. We used MaxEnt (program for modelling species distributions from presence-only species records) to predict current and future suitable areas. Two representative concentration pathways (RCP6.0 and RCP8.5) that represent different greenhouse gas concentration trajectories were modelled for the years 2050 and 2070. The isothermality, temperature seasonality and variation in seasonal precipitation were found to be the top three variables that affect the range of Stenoterommata species. Highly suitable habitat was found to increase with time for most species, except for S. platensis, whose distribution area may shrink by more than 50% by the year 2070. [ABSTRACT FROM AUTHOR]

Many studies have shown that vegetation structure and habitat complexity affect taxonomic composition, functional diversity, and the number of individuals in spider assemblages. These factors also affect spider body size, but mechanisms responsible for that are still not well understood. In our research, we examined the relationship between the body size of spiders from two species - Alopecosa cuneata and A. pulverulenta - and environmental factors such as habitat type and habitat complexity. Our research was conducted in the Bug River Valley on 12 plots covering three types of habitats: mesic meadow, sandy grassland, and xerothermic grassland. Spiders were collected in 2007-08 from April to mid-November using pitfall traps. In total we measured 334 males and 168 females of Alopecosa cuneata and 315 males and 104 females of A. pulverulenta. The generalized linear mixed model revealed that individuals of Alopecosa cuneata as well as A. pulverulenta reached larger sizes in more complex vegetation, whereas the habitat type did not affect the spider body size. One of the likely mechanisms responsible for a larger body size in more complex habitats is predator pressure. Birds as the main predators of spiders, being selective in their choice of prey, may collect larger spiders with higher intensity than smaller ones. We suggest that more complex habitats with dense vegetation provide better shelter for large spiders, which allows them to avoid predators. Our results indicate that habitat complexity may be an important determinant of body size distribution in spider assemblages. [ABSTRACT FROM AUTHOR]

Disturbance can play an important role in structuring stream food webs. Although floods have received the greatest attention as a disturbance agent in rivers, wildfire - which can strongly influence fluvial ecosystem structure and function - may also drive consumer trophic dynamics. We measured the relative effects of wildfire, hydrologic disturbance, ecosystem size, and canopy openness (as a proxy for in-stream productivity) on trophic position and reliance on aquatically-derived nutritional subsidies of riparian spiders of the family Tetragnathidae along two rivers on the west slope of the Sierra Nevada in California, USA. Ecosystem size received strong support as an environmental determinant of both trophic measures, with variability in flood magnitude emerging as an important mechanism linking ecosystem size and trophic responses. Piecewise linear regression revealed significant breakpoints in spider trophic position and reliance on aquatically-derived nutritional subsidies that were related to thresholds in fire extent within the catchment. These nonlinear relationships with wildfire may lend additional insight into the potential interactions among ecosystem size, productivity, and disturbance that determine stream-riparian food-web architecture. [ABSTRACT FROM AUTHOR]

We review the known information on the distribution and habitat affinities of the Micrargus herbigradus-species group in Poland. The analysis is based on a thorough literature survey, our own materials, and verification of some older collections. We give new diagnostic drawings and review the characters that are useful in identification of species within the group. Three species are present in Poland: M. herbigradus (Blackwall, 1854), M. apertus (O.-P. Cambridge, 1870) and M. georgescuae Millidge, 1976. The latter is recorded for the first time in the country, and we add numerous new localities for the two former species. Micrargus herbigradus is common and widespread in Poland, living in various habitats, with only a slight preference to forests. In contrast, M. apertus is widely distributed but rarely found, while its affinity to forests is the highest within the group. The records of this species are most numerous in lowland forests (up to c. 300 m a.s.l), but it can also be found at higher altitudes. M. georgescuae is found only in montane habitats, both in the Sudetes and the Carpathian Mountains, from above 650 m a.s.l. The adults of all three species occur the whole year round, but seem to be most abundant in May and June. [ABSTRACT FROM AUTHOR]

Many laboratory and field studies have been conducted on rice field spiders in China. There are 375 species, 108 genera, and 22 families of rice field spiders distributed within the major rice growing areas and 17 dominant species. The biological and ecological characteristics of 17 rice field spider species have been reported in detail. The biology and ecology of these species show significant differences among regions, farmland habitats, and agricultural practices. Future research should focus on rice field habitat diversity, enhancing the insecticide resistance of dominant spider populations, implementing large-scale breeding of spiders and augmentative release, breeding more leaf dominant species, conducting biosafety assessment of spiders in transgenic crops. [ABSTRACT FROM AUTHOR]

The relative roles of ecological niche conservatism versus niche divergence in promoting montane speciation remains an important topic in biogeography. Here, our aim was to test whether lineage diversification in a species complex of trapdoor spiders corresponds with riverine barriers or with an ecological gradient associated with elevational tiering. Aliatypus janus was sampled from throughout its range, with emphasis on populations in the southern Sierra Nevada Mountains of California. We collected multi-locus genetic data to generate a species tree for A. janus and its close relatives. Coalescent based hypothesis tests were conducted to determine if genetic breaks within A . janus conform to riverine barriers. Ecological niche models (ENM) under current and Last Glacial Maximum (LGM) conditions were generated and hypothesis tests of niche conservatism and divergence were performed. Coalescent analyses reveal deeply divergent genetic lineages within A . janus , likely corresponding to cryptic species. Two primary lineages meet along an elevational gradient on the western slopes of the southern Sierra Nevada Mountains. ENMs under both current and LGM conditions indicate that these groups occupy largely non-overlapping niches. ENM hypothesis testing rejected niche identity between the two groups, and supported a sharp ecological gradient occurring where the groups meet. However, the niche similarity test indicated that the two groups may not inhabit different background niches. The Sierra Nevada Mountains provide a natural laboratory for simultaneously testing ecological niche divergence and conservatism and their role in speciation across a diverse range of taxa. Aliatypus janus represents a species complex with cryptic lineages that may have diverged due to parapatric speciation along an ecological gradient, or been maintained by the evolution of ecological niche differences following allopatric speciation. [ABSTRACT FROM AUTHOR]

1. Patterns of species richness and species assemblage composition of ground-dwelling arthropods in primary successions along glacier forelands are traditionally described using a taxonomic approach. On the other hand, the functional trait approach could ensure a better characterisation of their colonisation strategies in these types of habitat. 2. The functional trait approach was applied to investigate patterns of functional diversity and life-history traits of ground beetles and spiders on an alpine debris-covered glacier and along its forefield in order to describe their colonisation strategies. 3. Ground beetles and spiders were sampled at different successional stages, representing five stages of deglaciation. 4. The results show that the studied glacier hosts ground beetle and spider assemblages that are mainly characterised by the following traits: walking colonisers, ground hunters and small-sized species. These traits are typical of species living in cold, wet, and gravelly habitats. The diversity of functional traits in spiders increased along the succession, and in both carabids and spiders, life-history traits follow the 'addition and persistence model'. Accordingly, there is no turnover but there is an addition of new traits and a variation in their proportion within each species assemblage along the succession. The distribution of ground beetles and spiders along the glacier foreland and on the glacier seems to be driven by dispersal ability and foraging strategy. 5. The proposed functional approach improves knowledge of the adaptive strategies of ground-dwelling arthropods colonising glacier surfaces and recently deglaciated terrains, which represent landforms quickly changing due to global warming. [ABSTRACT FROM AUTHOR]

There is considerable controversy around the patterns and processes that influence spatial variation in taxonomic composition in mountain environments. We analysed elevational variation in the taxonomic composition of epigaeic spider assemblages across five mountains in north-western Patagonia (Argentina) to examine the relative importance of dispersal (distance) limitation and environmental heterogeneity on a regional scale. The distance limitation hypothesis predicts greater taxonomic similarity between sampling sites separated by short geographical distances than between mountain peaks separated by longer distances, a lack of indicator species of macro-habitats, and weak associations between spider species composition and environmental gradients. Alternatively, the environmental heterogeneity hypothesis predicts that taxonomic differentiation will occur over short distances along elevation gradients in association with the turnover in major habitats and change in environmental conditions, and that indicator species will be present. We collected spiders using 486 pitfall traps arranged in fifty-four 100-m grid plots of nine traps separated by ~ 100 m of elevation, from the base to the summit of each mountain. Multivariate analyses identified spider assemblages that were associated with macro-habitats rather than with mountains. Local environmental variation (mainly in vegetation cover), precipitation and soil characteristics influenced the spatial variation in species composition. Characteristic indicator species showed high specificity and fidelity to macro-habitats, whereas vulnerable species showed high specificity and low fidelity to mountains or macro-habitats. We conclude that, on a regional scale, species adaptation to environmental gradients plays a more important role than dispersal limitation in structuring the taxonomic composition of spider assemblages. Moreover, the presence of indicator species suggests that spiders have a great potential as ecological indicators for evaluating the response of montane biodiversity to future climatic change. [ABSTRACT FROM AUTHOR]

The importance of artificial underground habitats for biodiversity is becoming more and more apparent. Abandoned railway tunnels are artificial, underground habitats of considerable biodiversity, including several species of conservation concern. We surveyed 16 abandoned railway tunnels in 2014 in Romania for the following faunal groups: amphibians, terrestrial isopods, and spiders. Amphibians occurred primarily in flooded tunnels, isopods were present in moist tunnels with woody debris, while spiders were widespread and exhibited the greatest diversity in railway tunnels. Some species of amphibians breed in tunnels. The greatest diversity was observed in the entrance zones of tunnels; because railway tunnels are generally isolated from the surrounding rock, they can be colonized only from the entrances. In areas lacking natural subterranean cavities and habitats, railway tunnels are important habitats for many species, including troglophilic spiders and soil-dwelling isopods. [ABSTRACT FROM AUTHOR]

A desert-living spider sparassid ( Cebrennus rechenbergi Jäger, 2014) and several lycosid spiders ( Evippomma rechenbergi Bayer, Foelix & Alderweireldt 2017, Allocosa senex (Mello-Leitão, 1945), Geolycosa missouriensis (Banks, 1895)) were studied with respect to their burrow construction. These spiders face the problem of how to transport dry sand and how to achieve a stable vertical tube. Cebrunnus rechenbergi and A. senex have long bristles on their palps and chelicerae which form a carrying basket (psammophore). Small balls of sand grains are formed at the bottom of a tube and carried to the burrow entrance, where they are dispersed. Psammophores are known in desert ants, but this is the first report in desert spiders. Evippomma rechenbergi has no psammophore but carries sand by using a few sticky threads from the spinnerets; it glues the loose sand grains together, grasps the silk/sand bundle and carries it to the outside. Although C. rechenbergi and E. rechenbergi live in the same environment, they employ different methods to carry sand. Geolycosa missouriensis lives in a moister habitat and produces solid sand pellets in which sand grains are caked together (without silk threads); the compact pellets are flung away from the burrow entrance by a rapid extension of the first legs. The spiders stabilize the developing tube inside by repeatedly adding silk rings, while digging down. This wall is very thin, consisting of only a few layers of crisscrossing silk threads. An excavated burrow collapses immediately, indicating that the stability is not due to the silk. Instead, the tight interconnection of neighboring sand grains-as in a vault-yields the necessary solidity to the burrow. [ABSTRACT FROM AUTHOR]