Spider Species Research Articles

Epigeic spider and ground beetles (Carabid) communities of semi-natural and natural habitats in agricultural landscape in Slovakia

Abstract We studied the spatial structure of spiders and beetles in 4 types of habitats in the Poloniny National Park. Between the years 2020 and 2021, we recorded 1,597 beetle specimens and 3,765 spider specimens using the pitfall trap method. The most represented beetles were Poecilus versicolor (53.4%), Nebria brevicollis (10.3%), Staphylinus caesareus (4.4%) and Amara familiaris (4.1%). Among the spiders, there were species Pardosa pullata (21.81%), Pachygnatha degeeri (14.21%), Xerolycosa nemoralis (10.28%), Pardosa palustris (7.86%), Trochosa ruricola (6.24%) and Alopecosa pulverulenta (4.38%). We confirmed the occurrence of two European important species of beetles (Carabus zawadzkii, Carabus variolosus) and 3 species of spiders belonging to the vulnerable species according to the IUCN threat status (Gongylidiellum vivum, Palliduphantes milleri and Xysticus lineatus). We also found the spider Micaria micans, which is new to the Slovak fauna and information about its distribution and habitat preferences in Slovakia is presented. Using multivariate analyzes (CCA, RDA) and classification species into bioindicative groups, we found a greater connection of adaptable and eurytopic species of ground beetles to the mesophilic meadow and of spiders to the habitat Nardetum pasture. Based on bioindicative groups of species (adaptable, eurytopic and relict), we found only a small difference in percentile points between spiders and beetles.

TAXONOMIC ACCOUNT OF SOME CRAB-SPIDERS OF SOUTHWEST REGION OF BANGLADESH

A taxonomic study on some crab-spiders genus Xysticus Koch was carried out in the southwest region of Bangladesh. Two species of spiders were identified in this study of which one species X. joyantiae n. sp. is identified as new to science and the other one X. minutus Tikader is a new record for the area of present study. Generic diagnosis, distribution, illustrated description and key to the species are described.

Effects of artificial night lighting on a web-building spider species in urban green spaces

Urban green spaces are biological habitats that play an important role in maintaining urban biodiversity and are affected by artificial light at night (ALAN). Determining the effects of ALAN on predators in urban green spaces is important for promoting the maintenance and conservation of these functions of insect communities in urban green spaces. We investigated the effects of ALAN on a web-building spider species (Trichonephila clavata) in urban green spaces in the Tokyo metropolitan area, Japan. We used a GPS receiver to determine the positions of streetlights and spider webs and classified the webs into two groups: those within the reach of streetlights and those outside their range. We then measured the web distribution (web density), web size, female traits (femur length and body weight), and male presence. Web densities in the light conditions were higher and web sizes smaller than those of webs in the no light conditions. Female body weight and length were also significantly lower in the light conditions than in the no light conditions. However, female body condition and male abundance did not differ between the light and no light conditions. Our results showed that T. clavata maintains some degree of fitness in urban fragmented green spaces although their physical characteristics and behaviour are altered by ALAN. Therefore, we suggest that measures to improve the quality within green infrastructure are required to maintain the function of generalist predators such as web-building spiders in urban green spaces.

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.

Does female control and male mating system predict courtship investment and mating outcomes? A comparative study in five widow spider species (genus Latrodectus) tested under similar laboratory conditions

BackgroundMale courtship investment may evolve in response to the male’s expectation of future mating opportunities or the degree of female control during mating interactions. We used a comparative approach to test this hypotheses by assessing the courtship and mating behaviors of five widow spider species (genus Latrodectus) under common laboratory conditions. We predicted male investment in courtship would be higher in species where males mate only once because of high cannibalism rates (monogyny, L. geometricus, L. hasselti, L. mirabilis), compared to species with rare cannibalism (L. mactans, L. hesperus) in which males should reserve energy for future mating opportunities. Increased male investment, measured as courtship duration, might also evolve with increased female control over mating outcomes if females prefer longer courtships. We tested this by assessing the frequency of copulations, timing of sexual cannibalism, and the degree of female-biased size dimorphism, which is expected to be negatively correlated with the energetic cost of rebuffing male mating attempts.ResultsCopulation frequency was consistently lower in species with extreme female-skewed size dimorphism, and where sexual cannibalism was more prevalent, suggesting the importance of female control for mating outcomes. We confirmed significant interspecific variation in average courtship duration, but contrary to predictions, it was not predicted by male mating system, and there was no consistent link between courtship duration and sexual size dimorphism.ConclusionWe show that the degree of sexual dimorphism is not only correlated with sexual cannibalism, but also with mating success since restriction of male copulation frequency by female Latrodectus affects paternity. However, predictions about male mating system or female control affecting courtship duration were not supported. We propose that the form of female control over mating and cannibalism, and male responses, might be more informative for understanding the evolution of courtship duration. For example, male tactics to avoid female aggression may drive lower courtship duration in species like L. mirabilis. Nonetheless, our results differ from inferences based on published studies of each species in isolation, illuminating the need for standardized data collection for behavioural comparative studies.

HcN57, A Novel Unusual Acidic Silk-Like Matrix Protein from Hyriopsis cumingii, Participates in Framework Construction and Nacre Nucleation During Nacreous Layer Formation.

In the classic molecular model of nacreous layer formation, unusual acidic matrix proteins rich in aspartic acid (Asp) residues are essential for nacre nucleation due to their great affinity for binding calcium. However, the acidic matrix proteins discovered in the nacreous layer so far have been weakly acidic with a high proportion of glutamate. In the present study, several silk-like matrix proteins, including the novel matrix protein HcN57, were identified in the ethylenediaminetetraacetic acid-soluble extracts of the nacreous layer of Hyriopsis cumingii. HcN57 is a highly repetitive protein that consists of a high proportion of alanine (Ala, 34.4%), glycine (Gly, 22.5%), and serine (Ser, 11.4%). It forms poly Ala blocks, GlynX repeats, an Ala-Gly repeat, and a Ser-Ala-rich region, exhibiting significant similarity to silk proteins found in spider species. The expression of HcN57 was specifically located in the dorsal epithelial cells of the mantle pallium and mantle center. Notably, expression of HcN57 was relatively high during nacreous layer regeneration and pearl nacre deposition, suggesting HcN57 is a silk matrix protein in the nacreous layer. Importantly, HcN57 also contains a certain content of Asp residues, making it an unusual acidic matrix protein present in the nacreous layer. These Asp residues are mainly distributed in three large hydrophilic acidic regions, which showed inhibitory activity against aragonite deposition and morphological regulation of calcite in vitro. Moreover, HcN57-dsRNA injection resulted in failure of nacre nucleation in vivo. Taken together, our results show that HcN57 is a bifunctional silk protein with poly Ala blocks and Gly-rich regions that serve as space fillers within the chitinous framework to prevent crystallization at unnecessary nucleation sites and Asp-rich regions that create a calcium ion supersaturated microenvironment for nucleation in the center of nacre tablets. These observations contribute to a better understanding of the mechanism by which silk proteins regulate framework construction and nacre nucleation during nacreous layer formation.

Fires and Clear-Cuttings as Local Areas of Arthropod Diversity in Polar Regions: Khibiny Mountains

The well-known phenomenon of attracting untypical animals to disturbed territories has been poorly investigated in the polar mountains. We studied arthropod diversity in self-healing industrial clear-cuts and burn areas in the Khibiny Mountains, Kola Polar region. Fieldworks were conducted at four sites, including a control mountain taiga forest and its three transformed variants: burnt forest, uncleared clear-cut, and twice-disturbed burnt clear-cut. Arthropods were collected using formalin traps 2–3, 5–6, and 8–9 years after industrial deforestation in 2012 and an extensive grass-roots fire in 2013. Out of 124 identified species (spiders—61; ground beetles—41; and rove beetles—22), 79 (or 64%) were collected in disturbed, primarily burned areas and were absent in control forest. We note ten species of rove beetles, nine species of ground beetles, and eight species of spiders for the first time in the well-studied arthropod fauna of the Khibiny Mts. We found that grass-root fires transform the soil vegetation covers in the polar mountain forests more powerfully in comparison with extensive deforestation and attract a greater diversity of arthropods with different preferences, enriching the fauna of the polar mountains and the Subarctic region as a whole. The attraction effect persists for, at least, a decade after the violations.

A new spider species of Belisana Thorell, 1898 (Araneae, Pholcidae) from Guizhou Province, south-western China.

China exhibits remarkable diversity of the spider genus Belisana Thorell, 1898, with 62 species recorded to date. However, the largest number of Belisana species was found in Yunnan Province (23 ssp.), while only seven species were found in Guizhou Province. In this paper, Belisanawangchengi sp. nov. as a new species is described from Guizhou Province, China.

Nutritional Status Does Not Restrict Foraging Activity and Web Investment in a Shelter-Building Spider Species, But Individuals are More Risk-Prone at Night

Nutritional Status Does Not Restrict Foraging Activity and Web Investment in a Shelter-Building Spider Species, But Individuals are More Risk-Prone at Night

Taxonomic notes on two poorly known lynx spider species from India (Araneae: Oxyopidae)

Taxonomic notes on two poorly known lynx spider species from India (Araneae: Oxyopidae)

Dominance structure and constancy of spiders in the Indian Thar desert

BackgroundThe knowledge about the species of a habitat (both resident and transient/dominant and rare) is a vital step to plan the conservation measures. Being generalist predators, spiders help controlling the population of their prey and maintain ecosystem stability. This makes spiders excellent bio-indicators for assessing the impact of anthropogenic disturbance factors on natural ecosystems (De, Siliwal, Uniyal and Hussain in Trop. Ecol. 63: 1–7, 2021). The aim of this study was to assess the dominance structure and constancy of spiders in three different habitats (Sand dunes, Riparian and Rocky) of the Thar desert. Study was conducted from March 2017 to February 2019 covering all seasons.ResultsThe eudominant species in sand dunes and rocky desert belonged to the family Thomisidae. These species were Tmarus sp. 1 and Tmarus kotigeharus Tikader, 1963, respectively. There were two eudominants in Riparian habitat (Oecobius putus O. Pickard-Cambridge, 1876 and Menemerus bivittatus (Dufour, 1831)). Through the analysis of constancy of all the species in the Thar desert, it was revealed that three species were constant in all the three habitats. The number of accessory and accidental species was far higher than constant species in all the habitats.ConclusionsThe number of accessory and accidental spider species in all habitats was far higher than constants due to the unstability of spider population. Therefore, this study highlights the necessity for conservation of these habitats of the Thar desert.

Changes in community composition and prey capture of web-building spiders during rice field development

Understanding the effects of microhabitat changes on arthropod predator communities and their prey in agroecosystems is essential for field management and biocontrol. Few studies have investigated the trait composition of web-building spider communities in rice ecosystems. Here, we examined how temporal changes during the rice field development affect the abundance and traits of orb-web spiders, and how these effects consequently influence captured prey number and prey composition in irrigated rice ecosystems in southern Thailand. We used structural equation models to evaluate direct and indirect, spider-mediated effects of rice field development on captured prey numbers in each different guild. We found that the number of horizontal web-building spiders decreased during the rice field development, whereas there was no significant change in number of vertical web-building spiders. The number of captured detritivorous insects was positively related to the numbers of horizontal and vertical web-building spiders, while phytophagous insects and others were positively related only to the numbers of vertical web-building spiders. Moreover, the prey number captured by vertical web-building spiders seems to be indirectly increased through the decreasing number of horizontal web-building spiders in the late rice season. A fourth-corner analysis showed that spider species identity, spider traits (web type, web height and web diameter), vegetation height, and water level generally influenced the prey captured by web-building spiders. Horizontal web-building spider species with lower web placement during the flooding phase captured high numbers of detritus-feeding insects, while vertical web-building spider species with higher web placement captured high numbers of rice pests, predators and others. Our results suggest that the field development acted as an environmental factor that determined the species identity and traits of web-building spider communities. The findings of this study can help to predict the ecosystem services provided by the web-building spider community in rice ecosystems.

Study on the Diversity and Distribution of Spider Fauna at Sree Krishna College Campus of Thrissur District, Kerala, India

Field survey was conducted to record the diversity of spiders at different sites in the Sree Krishna College Campus of Thrissur district during September 2022 to February 2023. Around 51 species of spiders belonging to 36 genera under 14 families were recorded. Salticidae family was represented with twelve species followed by Araneidae (10 sps.), Oxyopidae (5 sps.), Theridiidae (4 sps.), Lycosidae, (3 sps.), Tetragnathidae (3 sps.) and Sparassidae (3 sps.), Thomisidae (2 sps.), Pholcidae (2 sps.). But, Hersilidae, Linyphiidae, Uloboridae, Cheiracanthiidae and Sicariidae family members were very less. Spider population in different sites exhibited variation in species abundance and richness. Shannon index, Simpson index, Margalef Richness index, Berger-Parker index and Menhinick’s Index evaluated were 3.423, 0.9580, 9.540, 0.9101and 3.709 respectively. The abundance and percent occurrence of different spider species revealed variation in their distribution. For the study the entire campus has been surveyed, by dividing the area into four sites, Site A, Site B, Site C and Site D. Species composition and diversity indices studies revealed that more diversity in the site C followed by Site D, Site B and Site A. These types of surveys are important for the study of the prevalence of the spider population in given habitats and to create a biodiversity database of spider.

A new species of pelican spider (Araneae: Archaeidae) from the Whitsunday hinterland of central-eastern Queensland

Pelican spiders of the genus Austrarchaea Forster & Platnick, 1984 (family Archaeidae) are well represented in the tropical rainforests of central-eastern and north-eastern Queensland, with nine species currently described. However, this monophyleytic tropical fauna remains poorly documented relative to other lineages of Archaeidae from subtropical and temperate regions south of the St Lawrence Gap, with numerous additional species likely still unnamed. Here, we describe a new species from the Central Mackay Coast bioregion of central-eastern Queensland. Like other Australian Archaeidae, it is a short-range endemic taxon, known only from upland rainforest habitats in the Whitsunday hinterland near Airlie Beach. We show its clear morphological affinities to a closely related species from Eungella National Park, and further provide live habitus images and habitat information.

Integrative species delimitation and five new species of lynx spiders (Araneae, Oxyopidae) in Taiwan.

An accurate assessment of species diversity is a cornerstone of biology and conservation. The lynx spiders (Araneae: Oxyopidae) represent one of the most diverse and widespread cursorial spider groups, however their species richness in Asia is highly underestimated. In this study, we revised species diversity with extensive taxon sampling in Taiwan and explored species boundaries based on morphological traits and genetic data using a two-step approach of molecular species delimitation. Firstly, we employed a single COI dataset and applied two genetic distance-based methods: ABGD and ASAP, and two topology-based methods: GMYC and bPTP. Secondly, we further analyzed the lineages that were not consistently delimited, and incorporated H3 to the dataset for a coalescent-based analysis using BPP. A total of eight morphological species were recognized, including five new species, Hamataliwa cordivulva sp. nov., Hamat. leporauris sp. nov., Tapponia auriola sp. nov., T. parva sp. nov. and T. rarobulbus sp. nov., and three newly recorded species, Hamadruas hieroglyphica (Thorell, 1887), Hamat. foveata Tang & Li, 2012 and Peucetia latikae Tikader, 1970. All eight morphological species exhibited reciprocally monophyletic lineages. The results of molecular-based delimitation analyses suggested a variety of species hypotheses that did not fully correspond to the eight morphological species. We found that Hamat. cordivulva sp. nov. and Hamat. foveata showed shallow genetic differentiation in the COI, but they were unequivocally distinguishable according to their genitalia. In contrast, T. parva sp. nov. represented a deep divergent lineage, while differences of genitalia were not detected. This study highlights the need to comprehensively employ multiple evidence and methods to delineate species boundaries and the values of diagnostic morphological characters for taxonomic studies in lynx spiders.

Ant-eating spiders from Xizang, China (Araneae, Zodariidae).

Six species of the ant-eating spider of the family Zodariidae are described from Xizang, China, including five new species: Asceuachayusp. nov. (♀), A.dawaisp. nov. (♂♀), Mallinellamigusp. nov. (♂), M.mеdogsp. nov. (♂♀), and M.yadongsp. nov. (♂♀). The female of Cydrelalinzhiensis (Hu, 2001) is described here for the first time. Descriptions and photographs of all the species are provided.

Two new species of the genus Cheiracanthium C. L. Koch, 1839 (Araneae, Cheiracanthiidae) from China.

Two species of the long-legged sac spider genus Cheiracanthium C. L. Koch, 1839 collected from China are diagnosed and described as new to science: Cheiracanthiumbannaensissp. nov. (♂♀) from Yunnan Province and C.bifurcatumsp. nov. (♂♀) from Xinjiang Uyger Autonomous Region. Photos of the habitus and copulatory organs are given. In addition, DNA barcode information of the two new species is provided.

Impact of pre-copulatory sexual cannibalism on genetic diversity and efficacy of selection.

Factors that increase reproductive variance among individuals act to reduce effective population size (Ne), which accelerates the loss of genetic diversity and decreases the efficacy of purifying selection. These factors include sexual cannibalism, offspring investment and mating system. Pre-copulatory sexual cannibalism, where the female consumes the male prior to mating, exacerbates this effect. We performed comparative transcriptomics in two spider species, the cannibalistic Trechaleoides biocellata and the non-cannibalistic T. keyserlingi, to generate genomic evidence to support these predictions. First, we estimated heterozygosity and found that genetic diversity is relatively lower in the cannibalistic species. Second, we calculated dN/dS ratios as a measure of purifying selection; a higher dN/dS ratio indicated relaxed purifying selection in the cannibalistic species. These results are consistent with the hypothesis that sexual cannibalism impacts operational sex ratio and demographic processes, which interact with evolutionary forces to shape the genetic structure of populations. However, other factors such as the mating system and life-history traits contribute to shaping Ne. Comparative analyses across multiple contrasting species pairs would be required to disentangle these effects. Our study highlights that extreme behaviours such as pre-copulatory cannibalism may have profound eco-evolutionary effects.

Venom-microbiomics of eight species of Neotropical spiders from the Theraphosidae family.

Tarantulas are one of the largest predatory arthropods in tropical regions. Tarantulas though not lethal to humans, their venomous bite kills small animals and insect upon which they prey. To understand the abiotic and biotic components involved in Neotropical tarantula bites, we conducted a venom-microbiomics study in eight species from Costa Rica. We determined that the toxin profiles of tarantula venom are highly diverse using shotgun proteomics; the most frequently encountered toxins were ω-Ap2 toxin, neprilysin-1, and several teraphotoxins. Through culture-independent and culture-dependent methods, we determined the microbiota present in the venom and excreta to evaluate the presence of pathogens that could contribute to primary infections in animals, including humans. The presence of opportunistic pathogens with hemolytic activity was observed, with a prominence of Stenotrophomonas in the venoms. Other bacteria found in venoms and excreta with hemolytic activity included members of the genera Serratia, Bacillus, Acinetobacter, Microbacterium, and Morganella. Our data shed light on the venom- and gut-microbiome associated with Neotropical tarantulas. This information may be useful for treating bites from these arthropods in both humans and farm animals, while also providing insight into the toxins and biodiversity of this little-explored microenvironment.

Healing of Wounds by use of Spider threads in comparison with healing by Tetracycline ointment, an Experimental Analytical Study

Background: Spiders are distributed worldwide except in Arctic and Antarctica. More than 45,700 species of spiders and 114 families have been identified. Spiders produce silk in order to capture their prey. reported that people of the Carpathian Mountains used spider webs from Atypus spiders as bandages. Experiments showed that silk from spider house is bio-degradable, non-antigenic and non-inflammatory. These are ideal properties for healing wounds. We aimed to identify the effect of spider threads on healing wounds and injuries compared to healing of wounds by application of tetracycline ointment.Methods: This is an experimental analytical study in which we investigated ten participants tested in three groups. Group A participants were treated with tetracycline and group B were treated with spider threads. wooden rulers used to collect spider silk threads along with sterilizer, tissue, paper, bandages, and Tetracycline ointment. Silk was collected from four types of spiders: Cellar Spider, Salticidae Spider, Venatoria Hetropoda, and Galeodes Arabs. These spiders are the mostly distributed in Sudan. Silk was collected by using wooden rulers from cracks and corners of walls at Alzaiem Alazhari University and then placed on clean, soft tissue paper.Results: revealed that spider threads heal surface injuries without leaving scars in 90% of participants. The healing process with spider threads lasts between 8 -24 hours. The comparison between three tests showed that the percentage of wound healing was highest by 70% by using spider threads in comparison with tetracycline and self-healing.Conclusion: It was observed that healing of injuries by using spider threads was 70% faster than healing by using tetracycline ointment. Self-healing was observed to be faster than healing by use of tetracycline ointment.Keywords: Spider threads; Healing; Injuries; Tetracycline