Distribution Of Spiders Research Articles

Microhabitat selection and niche overlap: Drivers of spider coexistence in a tropical limestone cave

AbstractStable temperature, humidity, and oligotrophy may be essential in microhabitat selection, shaping niche overlap and species coexistence within cave ecosystems. To explore this hypothesis, we assessed the distribution and microhabitat preferences of four non‐obligate cave‐dwelling spiders: Loxosceles anomala, Scytodes itapevi, Philoponella vittata, and the exotic Oecobius navus. Using 1‐m2 quadrats, we surveyed spider distribution and abundance in a limestone cave, considering environmental conditions and prey availability during wet and dry periods. Significant differences were observed between moist and dry periods regarding light intensity, wind speed, air temperature and moisture, potential prey, and the abundance of L. anomala. The exotic spider O. navus was more specialist, preferred brighter habitats, and showed lower niche overlap. Conversely, the three native species displayed greater niche overlap and preferred darker and more humid environments. Spatial disparities, rather than temporal variation, in species distribution underscored the influence of cave habitat conditions on species segregation. Furthermore, our findings highlighted the limited ability of the non‐native O. navus to occupy more illuminated cave areas, thereby potentially safeguarding these habitats against biological invasion by this species.

Биотопическое распределение пауков-кругопрядов (Aranei: Araneidae) острова Аскольд (залив Петра Великого, Приморье)

The article presents the data on the species composition, abundance, spatial and biotopical distribution of orb-weaver spiders on Askold Island, located in Russia's Far East, in the Peter the Great Gulf (Primorsky Krai). The material was collected from 21 key sites of 3 x 25 m, by entomological sweeping and manually. A total of 507 spiders, belonging to 13 species from 8 genera, were captured. Of these, one species - Singa hamate - is indicated for the first time. On the island the most widespread spiders are of the genus Araneus, living in 11 out of 13 types of biotopes. For this genus, the most favorable are forest habitats, dominated by A. ishisawai and A. ventricosus. In open meadow biotopes, 8 species of spiders from 6 genera were recorded, with Neoscona adianta dominating: reaching the density of 29 specimens per 100 m2 in open plant communities with predominance of Artemisia gmelinii. In various parts of the island within linden and broad-leaved multi-species forests, the greatest diversity and abundance of orb-weaver spiders is recorded. There spiders from 3 genera (5 species of each) were caught. Their total density is 42.5 specimens per 100 m2. Stony beaches, stretching along the entire coast of the island, are characterized by the poorest faunal composition. One species encountered was Araneus ventricosus (4 specimens per 100 m2). For the Askold Island, a series of schematic distribution maps for the common species of orb-weaver spiders (A. ishisawai, A. ventricosus, A. macacus, Argiope bruennichi, Neoscona adianta, Plebs sachalinensis) has been compiled for the first time.

Spiders in Thailand (SIT) via spiderthailand.info: Thailand spider data retrieval system for geographical occurrence and photographic identification.

High biodiversity in the tropics is good for ecosystem services; however, challenges in taxonomy and identification usually come from such high biodiversity. Spiders are no exception to the challenges. Identifying spiders in tropical places like Thailand is difficult and time consuming. To reduce the difficulty of identifying Thai spiders, a data retrieval system for geographical occurrence and photographic identification was conducted to deploy on an online platform, Spiders in Thailand (SIT) via the website "spiderthailand.info". This allows professional arachnologists and amateur spider lovers to visit and check the geographical distribution of Thai spiders and to quickly access pictures for comparative photographic identification. To facilitate Thai spider identification, there were two parts, the database and the website, which are connected to each other. Data of Thai spiders were extracted from the World Spider Catalog to build a database comprising geographical occurrence and pictures of spider species in Thailand. The database was then linked with the website to display data. The dataset of pictures and illustrations extracted from taxonomic literature of the World Spider Catalog were included in the database for connecting with the online platform, Spiders in Thailand (SIT) via the website "spiderthailand.info" which facilitated access to pictures and illustrations, expediting the identification of Thai spider specimens. Geographical occurrences of Thai spiders consisted of 1419 records belonging to 670 species of 228 genera and 50 families. Amongst those, 461 species from 133 genera of 41 families were distributed only in Thailand. Around Thailand, 756 geographical localities were reported for spider occurrences. From 76 provinces and one additional special administrative area (Bangkok), 58 provinces showed occurrence records of spiders and 18 provinces showed non-occurrence records. Those provinces of non-occurrence records of spiders were Amnat Charoen, Ang Thong, Bueng Kan, Chai Nat, Maha Sarakham, Mukdahan, Nakhon Phanom, Nong Bua Lam Phu, Nonthaburi, Phayao, Phichit, Phra Nakhon Si Ayutthaya, Samut Prakan, Samut Sakhon, Si Sa Ket, Sing Buri, Uthai Thani and Yasothon. Most spiders were reported from Chiang Mai Province.

The sicariid spiders in the state of Bahia, Brazil (Arachnida: Araneae).

Sicariidae is a small family of cryptic and recluse spiders, with 178 species grouped into three genera: Hexophtalma, Loxosceles and Sicarius. Only the last two occur in Brazil, where 29 species are recorded, with a greater number of records in the Southeast and South regions. To date, there is no regionalized study of the distribution of these spiders in the Northeast of Brazil. We presented more than four decades of data on the distribution of sicariid spiders in the state of Bahia. Our research aimed to identify and evaluate the distribution of sicariid species in this region, characterizing them in their biomes and phytophysiognomies. Data covers a period from 1983 to 2024, obtained from articles describing species recorded in Bahia and from three scientific collections from Brazilian institutions: Universidade Federal da Bahia (MHNBA); Instituto Butantan (IBSP); Universidade Federal de Minas Gerais (UFMG). Maps were produced using the QGIS 3.34.1 software, based on geographic coordinates obtained from the original literature, when provided. Species without information on geographic coordinates were georeferenced using the SpeciesLink (geoLoc tool) for the municipalities. Biomes were consulted on the georeference Brazilian institute website and the phytophysiognomies were ignored when not specified in the data of collections or original literature. We confirmed 14 species of sicariid spiders in the state of Bahia, eight from the genus Loxosceles (i) and six from Sicarius. The species were recorded in 48 municipalities, located mainly in the Caatinga biome. We recorded a distribution expansion of seven species: Loxosceles amazonica, L. chapadensis, L. karstica, L. similis, Sicarius cariri, S. ornatus and S. tropicus. There is a difference in species composition in the two regions separated by the São Francisco River, an important geographic barrier especially for small invertebrates. More than 75% of the species were registered in the east side and about 20% exclusively in the west side: L. boqueirao, L. cardosoi, L.carinhanha. This suggests the need for future studies to evaluate additional variables that determine community structure, especially considering their low vagility and reclusive behavior. Although Sicarius are found almost exclusively in the Caatinga, there are isolated records from Restinga and dry forest enclaves in the Cerrado domain and Atlantic Forest areas. This reinforces the possibility of them being able to adapt to slightly wetter environments erase colonize and survive in seasonally dry rainforest areas. Unlike Sicarius (i), Loxosceles (i) occupy a wide variety of habitats in natural, urban and domiciliary situations. Many of the records here such as for Loxosceles boqueirao, L. cardosoi, L. carinhanha, L. chapadensis, L. karstica and L. troglobia were obtained at caves or nearby areas, which appear to be attractive habitats for these nocturnal spiders.

Coexistence of Ammoxenus (Gnaphosidae) spider species on and between termitaria of Microhodotermes viator (Hodotermitidae) at a Karoo site

Previous studies of some species of Ammoxenus spiders demonstrated them to be monophagous predators of certain termites. Upon observing Ammoxenus spiders preying on the hodotermitid, Microhodotermes viator, we examined the distribution of spiders on or off termitaria (termed heuweltjies) at the Tierberg-LTER study site in the Karoo using pitfall traps deployed monthly over two years. Four species of Ammoxenus were found, but only one, Ammoxenus pentheri, has been described, the other three being new to science. Their coexistence prompts questions concerning niche partitioning among several specialist predators. Our initial study revealed that Ammoxenus and other ground spiders were more abundant on heuweltjies than in the matrix between heuweltjies. The different Ammoxenus species appeared to be disparately associated or disassociated with heuweltjies and had different phenologies. This case of niche partitioning among specialist predators warrants further study.

A survey of pholcid spiders (Araneae, Pholcidae) from Guiyang, Guizhou Province, China.

The family Pholcidae C.L. Koch, 1850 is highly diverse in Guizhou Province, southwestern China, and currently contains four genera and 22 species. Nevertheless, the distribution of pholcid spiders is conspicuously patchy in Guizhou. Species from Guiyang are poorly studied, and only Pholcusspilis Zhu & Gong, 1991 has been recorded. A survey was undertaken for the first time to study the pholcids in Guiyang. A total of four species are reported, comprising Belisanayuhaoi Yang & Yao, sp. nov. and three other species: Leptopholcustanikawai Irie, 1999 (new record for Guiyang), Pholcusspilis Zhu & Gong, 1991 and Spermophorasenoculata (Dugès, 1836) (new record for Guizhou).

Diversity and ecological dynamics of ground and understory arachnid spiders from a lowland tropical forest in Sumber Pawon, Kediri, East Java

Spiders have significantly contributed to the dynamics of terrestrial ecosystems and play an essential role as appropriate bio-indicators to monitor habitat changes. We aim to determine the composition and local scale diversity of spiders in the understory and ground layers and to determine habitat preferences regarding the distribution of spiders in the interior forests and riparian forests. Sampling was conducted at a protected forest area in Sumber Pawon Kediri, covering an area of 12.45 Ha during the wet season (January-March). The study’s results found 340 individuals consisting of 15 families and 63 species. Family Araneidae and species Hamadruas superba are the most common taxa groups in the interior forests, while Hippasa holmerae are in riparian forests. More individuals and species are found understorey shrubs in forest interiors. Soil temperature, relative humidity, and litter thickness positively correlate with spider abundance. Resource partitioning observation showed that leaf litter and herbaceous plants contain more potential prey for spiders. Forest habitat management programs must consider the spatial variation of spiders between strata, as well as the response of the spiders to the seasons. A better understanding of spider ecological dynamics will support the sustainable management of forest ecosystems.

Two-Dimensional Projection of Distribution and Abundance of Common Species of Spiders and Beetles in South Korea Caused by Climate Change

The selection of explanatory variables is very important in a species distribution model for predicting changes in the distribution of organisms caused by climate change. In this study, a two-dimensional prediction of the abundance and distribution of beetles and spiders using temperature and precipitation was compared with the results of previous studies that employed a one-dimensional prediction using temperature. This study used the data from previous surveys for 366 forest sites in South Korea between 2006 and 2009 using pitfall traps. Species distribution models were created for 51 species with a high occurrence (collected from more than 10% of the total sites). A generalized additive model (GAM) was used for the distribution models. The future abundance and distribution based on climate scenarios RCP 4.5 and 8.5 were predicted by selecting 35 species from 51 common species for which climatic factors (temperature and precipitation) had a significant effect on abundance and distribution. In a two-dimensional prediction using temperature and precipitation, the range of change was larger compared with a one-dimensional prediction using temperature, and precipitation had a significant effect on decreasing species.

Vertical distribution of spiders (Araneae) in Central European shallow subterranean habitats

Shallow subterranean habitats are among the last habitats in Central Europe to be arachnologically researched. Using stratified pipe traps, we studied the vertical distribution of spiders in soil and interspaces in bedrock (shallow subterranean habitats). Specifically, we sampled fauna in different substrates, including limestone, sandy marlstone, sandy marl, claystone, loess, and artificial gravel accumulation. Employing stratified pipe traps allowed us to identify the depth at which particular species occurred. Across multiple years and sampling sites, we collected 76 spider species, 21 of which showed an affinity for subterranean microhabitats. Some of these species occurred in interspaces in soil and bedrock, whereas others have been previously found in subterranean ant nests and animal burrows. We collected five species (Iberina microphthalma, Centromerus cf. piccolo, Porrhomma cambridgei, P. microcavense, and P. microps) almost exclusively at depths over half a meter, suggesting the strong affinity of these species for a subterranean lifestyle. We provide diagrams of these species’ vertical distribution and photo-document eye reduction. Our study demonstrates that poorly studied shallow subterranean habitats harbor diverse subterranean spider fauna, including several previously considered rare species in Central Europe.

Diversity and distribution of spiders from Tenkasi district, India

Biodiversity can be simply defined as the variety of all types of living organism. Spiders are among the most diverge groups on earth, which received the seventh ranking in global diversity after the sixth largest insect orders. Spiders are major playing a vital role in the forest ecosystem is the spiders. The spotted spider specimens were taken photographed identified without disturbing it. A total of 17 species of spiders under 15 genera and 9 families were recorded during the Four months survey in five falls in Coutrallam, Tenkasi district, Tamilnadu state, India.

Elevation gradient affects the distribution and host utilisation of Zatypota anomala (Hymenoptera, Ichneumonidae) associated with mesh web weaving spiders (Araneae, Dictynidae)

The spatial distribution of parasitoids is closely linked to the distribution and ecological requirements of their hosts. Several studies have documented changes in the fauna composition of parasitoids in response to elevation, but data on parasitoids associated with spiders are missing. The koinobiont ichneumonid wasp Zatypota anomala is strictly specialised on spiders of the genus Dictyna (Dictynidae) in Europe. We examined the distribution of spiders of the family Dictynidae in forest ecotones in central Europe across a broad elevation gradient (110–1466 m a.s.l.). We checked the spiders for parasitism by Z. anomala. It was most abundant at the mid-elevations (median 712 m a.s.l., range 179–870 m a.s.l.). We identified four dictynid spider species as Z. anomala hosts. These were Dictyna arundinacea, Dictyna uncinata, Nigma flavescens, and Nigma walckenaeri. All four species and the genus Nigma were recorded as hosts for the first time. The parasitoids strongly preferred juvenile instars of their hosts. The body length differed between parasitised Dictyna and Nigma spiders (medians: 1.95 mm and 2.55 mm, respectively). The distribution of Dictyna and Nigma spiders overlapped along the elevation gradient, but parasitism incidence significantly differed between spider genera along the elevation gradient. Nigma was parasitized at lower elevations between 179–254 m a.s.l. and Dictyna at higher elevations between 361–870 m a.s.l. The phenology of Z. anomala is closely tied to the univoltine life strategy of its host spiders. The parasitoid female oviposits in autumn, and its offspring overwinter as larvae on the host, reach adulthood during spring, and pass the summer as an adult.

Population Distribution and Habitat Occupancy of Spiders (Order : Araneae) in the Tropical Caves of Baratang Island, Andaman and Nicobar Islands, India

Population Distribution and Habitat Occupancy of Spiders (Order : Araneae) in the Tropical Caves of Baratang Island, Andaman and Nicobar Islands, India

Spatial distribution of spiders (Aranei) and other groups of soil macrofauna in the arctic tundra of northeastern Taimyr, Russia

Spatial distribution of spiders (Aranei) and other groups of soil macrofauna in the arctic tundra of northeastern Taimyr, Russia

A review of faunistic bibliography relating to spiders (Aranae) in Poland

The study provides a comprehensive list of publications concerning data on spider distribution in Poland. A list includes 1089 original papers, book chapters, books, conference papers with original records on spider species from the contemporary territory of Poland. The list was updated as of December 31, 2020.

Influence of urbanization characteristics on ant (Hymenoptera: Formicidae) and spider (Arachnida: Araneae) diversity

Demographic characteristics and length of land use occupation time are important factors in the evaluation of the influence of urbanization on biodiversity. Thus, the aim of this study was to evaluate how population density and human occupation history influence taxonomic and guild spider (Arachnida: Araneae) and ant (Hymenoptera: Formicidae) diversities in four distinct Administrative Regions (ARs) of the municipality of Salvador (Bahia, Brazil). The ants and spiders in the ARs were collected in different types of green areas: forest fragments, vacant lots, and gardens/backyards, using three capture techniques (Winkler trap, entomological umbrella, and manual collection). We tested for eventual differences in myrmecofauna and araneofauna richness and composition, in addition to guilds (FGs) according to population density level (high vs. low) and urbanization time (old vs. recent). A total of 148 ant species were collected and classified into 15 guilds. Whereas a total of 97 spider species were captured and classified into 10 guilds. Spider richness varied significantly between the ARs, instead of to ant richness. There were also significant differences between ARs for the taxonomic composition of spiders, but not for ants. Those of the guild compositions of ants and spiders were not significant. Finally, our results indicate the importance of how historical processes of neighborhood occupation influence the distribution of spiders, demonstrating increased richness in areas with lower population densities, while other factors related to urban landscapes may be related to the distribution of ant and spider species.

The Ecology of Spider Sociality: A Spatial Model.

AbstractThe emergence of animal societies offers unsolved problems for both evolutionary and ecological studies. Social spiders are especially well suited to address this problem given their multiple independent origins and distinct geographic distribution. On the basis of long-term research on the spider genus Anelosimus, we developed a spatial model that re-creates observed macroecological patterns in the distribution of social and subsocial spiders. We show that parallel gradients of increasing insect size and disturbance (rain, predation) with proximity to the lowland tropical rain forest would explain why social species are concentrated in the lowland wet tropics but absent from higher elevations and latitudes. The model further shows that disturbance, which disproportionately affects small colonies, not only creates conditions that require group living but also tempers the dynamics of large social groups. Similarly simple underlying processes, albeit with different players on a somewhat different stage, may explain the diversity of other social systems.

Spiders in Brazil: from arachnidism to potential therapeutic use of their venom part 1 of 2

Spider envenomation, generically known as arachnidism, is described in many places around the world. In terms of medical importance, the following genera of animals stand out as the main origin of the morbid condition: Atrax (Sidney funnel web spider), Steatoda (false black widow), Latrodectus (black widow), Loxosceles (brown spider) and Phoneutria (armed spider), the last three causing accidents involving spiders in Brazil. This article, part 1 of 2, aims to present the main aspects of arachnidism in the country, with an emphasis on the biology and geographical distribution of spiders, biochemistry of the venom, pathogenesis and epidemiology of arachnidism, as well as prevention of the morbid condition. KEY WORDS: Arachnidism; araneae; spider bites; spider venoms.

Recovered grassland area rather than plantation forest could contribute more to protect epigeic spider diversity in northern China

Several studies have documented the semi-natural habitats and heterogeneous landscape patterns play a crucial role in maintaining spider diversity in agricultural landscapes. However, which types of semi-natural habitat contribute more to conserve spider diversity and functional traits, and how they respond to landscape patterns at different landscape scales are still poorly understood. Thereby, we sampled epigeic spider communities by pitfall traps within recovered grasslands, plantation forests and croplands around three villages with different altitudes in northern China and surveyed the surrounding landscape structures in both 2017 and 2018. The results confirmed the diverse distribution of spiders in different habitat types. There was a greater spider activity density in recovered grasslands than that of plantation forests or croplands significantly. Furthermore, both recovered grasslands and plantation forests contained more species richness than croplands. Moreover, the spider community in the recovered grasslands and cropland had more similar functional trait compositions (including hunting types, body size and ballooning ability) comparing to the plantation forests, which mainly due to the higher proportion of ambush hunters in recovered grassland and cropland. Secondly, the study also indicated that the proportion area of plantation forest negatively affected spider diversity at multi-scales. Meanwhile, recovered grassland with high landscape diversity would benefit spider diversity only on a small scale like a 100 m radius. The spider functional traits were insensitive to landscape patterns. Overall, the study implies that increasing recovered grassland rather than plantation forest could protect spider diversity in northern China. The findings presented in this paper added to our understanding of how landscapes and different semi-natural affect the diversity of spiders and their functional traits. Meanwhile, the research results represent a further step towards developing more suitable landscape patterns and choosing restoration semi-natural types for policymakers to enhance biodiversity in agricultural landscapes.

Diversity of spiders (Arachnida: Araneae) and the impact of pruning in Indian sandalwood plantations from Karnataka, India

Indian sandalwood Santalum album L. plantations in Karnataka were surveyed to study the diversity and abundance of spider fauna. A total of 1,244 individuals belonging to 56 spider species in 40 genera under 14 families were recorded in the sandalwood plantations. Among the spider families recorded, Araneidae was the most dominant with 15 species in nine genera followed by Salticidae with 13 species in 10 genera, Thomisidae with seven species in four genera, Oxyopidae with four species in three genera, Uloboridae with four species in a genus, and Theridiidae by three species each under three genera. Lycosidae and Sparassidae are represented by two species under two genera each. The families Cheiracanthiidae, Clubionidae, Hersiliidae, Philodromidae, and Pholcidae are represented by a species each. The pruning of sandalwood revealed a significant negative effect on the occurrence and distribution of spiders.

Phylogenomic Analysis of Ultraconserved Elements Resolves the Evolutionary and Biogeographic History of Segmented Trapdoor Spiders.

The segmented trapdoor spiders (Liphistiidae) are the sole surviving family of the suborder Mesothelae, which forms the sister lineage to all other living spiders. Liphistiids have retained a number of plesiomorphic traits and their present-day distribution is limited to East and Southeast Asia. Studying this group has the potential to shed light on the deep evolutionary history of spiders, but the phylogeny and divergence times of the family have not been resolved with confidence. We performed phylogenomic and molecular dating analyses of 2765 ultraconserved element loci from 185 liphistiid taxa. Our analyses show that the crown group of Liphistiidae appeared in the mid-Cretaceous at 102 Ma (95% credibility interval 92-113 Ma), but it was not until the Neogene that much of the diversification within the family occurred in mainland Southeast and East Asia. This diversification was coincident with tectonic events such as the extension of the East Asian continental margin, as well as geological upheavals in Indochina induced by the collision between India and Asia. Our study highlights the important role of major tectonic events in shaping the evolutionary history, present-day diversity, and geographical distribution of mesothele and liphistiid spiders. [biogeography; concatenation; Liphistiidae; molecular dating; summary coalescent; UCEs.].