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The remarkable material properties of spider silk, such as its high toughness and tensile strength combined with its low density, make it a highly sought-after material with myriad applications. In addition, the biological nature of spider silk makes it a promising, potentially sustainable alternative to many toxic or petrochemical-derived materials. Therefore, interest in the heterologous production of spider silk proteins has greatly increased over the past few decades, making recombinant spider silk an important frontier in biomanufacturing. This has resulted in a diversity of potential host organisms, a large space for sequence design, and a variety of downstream processing techniques and product applications for spider silk production. Here, we highlight advances in each of these technical aspects as well as white spaces therein, still ripe for further investigation and discovery. Additionally, industry landscaping, patent analyses, and interviews with Key Opinion Leaders help define both the research and industry landscapes. In particular, we found that though textiles dominated the early products proposed by companies, the versatile nature of spider silk has opened up possibilities in other industries, such as high-performance materials in automotive applications or biomedical therapies. While continuing enthusiasm has imbued scientists and investors alike, many technical and business considerations still remain unsolved before spider silk can be democratized as a high-performance product. We provide insights and strategies for overcoming these initial hurdles, and we highlight the importance of collaboration between academia, industry, and policy makers. Linking technical considerations to business and market entry strategies highlights the importance of a holistic approach for the effective scale-up and commercial viability of spider silk bioproduction.

Studies of adaptive radiations have played a central role in our understanding of reproductive isolation. Yet the focus has been on human-biased visual and auditory signals, leaving gaps in our knowledge of other modalities. To date, studies on chemical signals in adaptive radiations have focused on systems with multimodal signalling, making it difficult to isolate the role chemicals play in reproductive isolation. In this study we examine the use of chemical signals in the species recognition and adaptive radiation of Hawaiian Tetragnatha spiders by focusing on entire communities of co-occurring species, and conducting behavioural assays in conjunction with chemical analysis of their silks using gas chromatography-mass spectrometry. Male spiders significantly preferred the silk extracts of conspecific mates over those of sympatric heterospecifics. The compounds found in the silk extracts, long chain alkyl methyl ethers, were remarkably species-specific in the combination and quantity. The differences in the profile were greatest between co-occurring species and between closely related sibling species. Lastly, there were significant differences in the chemical profile between two populations of a particular species. These findings provide key insights into the role chemical signals play in the attainment and maintenance of reproductive barriers between closely related co-occurring species.

The extent to which neural representations of fear experience depend on or generalize across the situational context has remained unclear. We systematically manipulated variation within and across three distinct fear-evocative situations including fear of heights, spiders, and social threats. Participants (n = 21; 10 females and 11 males) viewed -20 s clips depicting spiders, heights, or social encounters and rated fear after each video. Searchlight multivoxel pattern analysis was used to identify whether and which brain regions carry information that predicts fear experience and the degree to which the fear-predictive neural codes in these areas depend on or generalize across the situations. The overwhelming majority of brain regions carrying information about fear did so in a situation-dependent manner. These findings suggest that local neural representations of fear experience are unlikely to involve a singular pattern but rather a collection of multiple heterogeneous brain states. [ABSTRACT FROM AUTHOR]

In many animals, early-life decisions influence long-term fitness. Mantidflies are spider egg predators; their tiny larvae climb aboard spiders to find eggs, but little is known about how they find spiders. We tested the hypothesis that mantidfly larvae (Dicromantispa sayi) detect and respond to substrate-borne spider cues (e.g., silk and/or excreta). We presented larvae with filter paper exposed to different types of spiders (adult female, adult male, or juvenile Habronattus trimaculatus jumping spiders) versus a no-cue control. Larvae spent more time on filter paper with spider cues. We then tested the hypothesis that mantidflies make finer distinctions between spiders when given direct choices between these cues. Larvae did not discriminate between sexes but spent more time (and exhibited more phoretic behavior) on filter paper with female or male cues compared with juvenile cues. While this suggests that mantidflies actively seek out adult spiders, we also found that adult spiders were more active than juveniles and may have simply deposited more silk and excreta, providing a stronger cue to detect. We discuss these findings in the context of the risks and benefits of different spider hosts, and how early-life spider-searching strategies may shape a mantidfly's long-term fitness. [ABSTRACT FROM AUTHOR]

Predators can alter the movement of nutrients through ecosystems by depositing waste products following predation. Whilst the benefits of predator waste for large predators (e.g. bears) or dense accumulations of predators (e.g. seabirds on islands) seem clear, less is known about whether smaller, solitary predators can have measurable effects on local ecosystem processes. In separate experiments with web‐building and wandering spiders, we tested if the presence of predators affected soil nutrient content, soil respiration, soil microbial communities, and plant growth. In the first experiment with black widow spiders, total nitrogen and nitrate were not affected by spider presence, but ammonia and phosphorus were higher from soil under the edge of the spider web than soil away from the spider. Soil respiration and plant growth were both higher in soil collected from under the spider retreat compared with soil collected away from the spider web. In a second experiment with wolf spiders, we tested for interactions between spiders and soil microbial communities. There were positive effects of wolf spider presence on all soil nutrients and there were interactions between spiders and soil type (i.e. field‐collected versus autoclaved) for total carbon, total nitrogen, nitrate, and pH. Spider presence and soil type also affected soil respiration and spider presence had a large effect on the composition of the microbial community of the soil. There were also positive effects of wolf spider presence on plant biomass and plant height, with a significant interaction between spiders and soil type for plant height. Overall, our results show that two spiders with different life histories (i.e. web‐building and wandering) both have significant positive effects on plant growth through the deposition of their waste products. These effects may occur through the direct deposition of nutrients and changes in soil microbial communities. Although, further work is needed to resolve these interactions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

Extracting regularities and probabilities from the environment is a fundamental and critical ability in an ever-changing surrounding. Previous findings showed that people are highly efficient in learning these regularities and that emotional stimuli are better learned than neutral ones. Yet, the generality and the underlying mechanism of this benefit are poorly understood. Here, participants viewed a stream of images with negative and neutral valence. Unbeknownst, the items recurred in regularity as triplets. Then, to assess learning, a surprised familiarity test was conducted. The results of Experiment 1, using two sets of stimuli, found better statistical learning for negative triplets than for neutral triplets. Experiment 2 revealed similar benefits even when only a single negative item was in the triplet at the second or third position, suggesting the advantage is not cumulative. We speculated that the predictability of the negative items is driving the effect. Consequently, Experiment 3 confirmed that the memory for neutral items preceding negative items was better than for neutral items preceding neutral items. Together, these findings provide novel insights into the mechanism of how the learning of incidental temporal associations is influenced by negative stimuli and the role of predictability in the negative valence benefit. [ABSTRACT FROM AUTHOR]

Semiochemicals left by predators in their foraging area can be utilised by prey to avoid predation. The range of predators' chemical cues with contrasting degradation rates might provide information of different quality, potentially allowing prey to differentiate between the immediate and the longer-term presence of predators in a location. So far, knowledge about the roles of volatile versus stable chemical cues in informing predation risk is limited. We here seek to disentangle the role of ephemeral trail pheromones compared to persistent cuticular hydrocarbons of ants (predators) on the antipredator behaviour of juvenile spiders (prey), with the expectation that volatile semiochemicals induce avoidance behaviour in spiders at a higher rate compared to stable cues. We allowed the spiders to choose between sites with and without ant cues separately for volatile trail pheromones and stable hydrocarbons. Unexpectedly, spiders avoided the presence of persistent cuticular hydrocarbons more clearly than the highly volatile trail pheromone. This underscores the widespread impact of these stable cues on the avoidance behaviour of potential intraguild prey. The response to trail pheromones was unclear, possibly because spiders always encounter these cues simultaneously with visual and vibratory cues from ants; hence, trail pheromones may not contain any additional information, hindering the evolution of the ability to detect them. [ABSTRACT FROM AUTHOR]

Himalayan orogeny and consequent climatic changes, such as the strengthening of the Asian monsoon, are considered as two main drivers in shaping local biogeography. The mountainous Sinopoda spiders, which are widely distributed in East Asia and Southeast Asia and especially abundant in the mountains near the Himalayas, represent an ideal model lineage for investigating Himalayan biogeography. This is due to their high diversity, limited dispersal ability, and wide elevational distribution, ranging from sea level up to 3500 meters. We investigated the evolutionary history of Sinopoda spiders, focusing on ecological, molecular, and morphological traits in relation to local geological events and fluctuations in Neogene (23.0–2.6 Ma) Asian monsoon patterns. Distribution modeling results show that extant Sinopoda spiders are sensitive to humidity fluctuations. They are mainly distributed in two distinct habitats: areas with moderate precipitation at high altitude (relatively cold) and areas with high precipitation at low altitude (relatively warm). The biogeographical and elevation reconstruction analyses show that as the Himalayas rose and the Asian monsoon intensified, Sinopoda spiders (Sparassidae: Heteropodinae) moved out of the Himalayas (ca 18.1 Ma) then 'down' the rising mountain slopes (ca 9.6 Ma). We then see a secondary return to the mountains (ca 3.3 Ma) as the severity of the East Asian monsoon decreased. We hypothesize that our 'out of Himalaya' dispersal pattern hypothesis will also apply to closely related spider groups with limited ballooning ability (e.g. Lycosidae, Thomisidae) or other organisms with low vagility (such as herpetofauna) that are sensitive to humidity and possess similar geographical distributions. [ABSTRACT FROM AUTHOR]

Predation exerts a profound influence on the evolution of camouflage and detection abilities in both predators and prey. For instance, flower‐visiting spiders need to ensure their concealment when ambushing on flowers, which compels pollinators to check any spider cues cautiously before landing. Although numerous studies have examined the visual camouflage of spiders deceiving bees, little is known regarding whether spiders also employ olfactory camouflage. Additionally, the detection of spiders by dipteran insects is often overlooked, despite them being major non‐bee pollinators. Here, we explored the detection ability of dipteran pollinators and the crypsis skill of spiders from both olfactory and vision perspectives using the housefly Musca domestica L. (Diptera: Muscidae) as prey, the crab spider Ebrechtella tricuspidata (Fabricius) (Araneae: Thomisidae) as predators and chamomile Matricaria recutita L. (Asteraceae) as substrates. Our olfactory experiments revealed that experienced houseflies could respond to and avoid spider odour. However, this response did not appear to be innate, as naive individuals showed no aversion. Moreover, experienced houseflies did not have any avoidance behaviours to the mixed odours of spider and flower, indicating that spiders achieved olfactory crypsis utilizing floral scent. Our vision experiments and visual modelling demonstrated that houseflies could detect spiders positioned on flower. Surprisingly, instead of avoiding them, houseflies exhibited a preference for flowers occupied by female spiders, suggesting the attractive nature of female spider colouration. This paper provides evidence for the first time that crab spiders use floral scent to achieve olfactory crypsis and proposes a potential yellow‐signalling mechanism for crab spiders to attract insects. [ABSTRACT FROM AUTHOR]

• Refugia or refuges are a concept that can contribute to an understanding of survival in the Anthropocene at different levels of abstraction. • Urban green spaces are areas where interactions between human and non-human nature can occur. They serve as refuges in the city and can be beneficial for both biodiversity and human well-being. • Over 70 % of the reviewed studies report positive effects of unmown refuges on arthropod abundance and richness in meadows or green spaces. • Unmown refuges allow habitat heterogeneity, a shelter for surviving arthropods from mowing, a chance for larval development, and a place to hibernate. Large refugia and small refuges have always been crucial for species survival, particularly during periods like the Ice Age. When their original habitats became uninhabitable, they provided important shelters in space and time. Drawing from a biological and philosophical perspective, we propose creating and preserving refuges as socio-ecological solutions in an epoch primarily shaped by human activity, the Anthropocene. Our focus lies on green refuges within urban settings, given that urbanization is one of the large drivers of insect decline and has adverse effects on humans, such as increased heat. Refuges can be beneficial for both biodiversity and human well-being. After clarifying the relevant terminology on four levels of abstraction, we conducted a systematic biological literature review - as a case study. Here, we summarize the current state of research on the effects of unmown refuges on insects and spiders. The mere existence of refuges proved beneficial for arthropods, with over 70 % of studies reporting positive responses among these species. While insects and spiders have specific habitat requirements, humans are able to create a habitable environment for themselves. However, ecological crises for humans and arthropods are increasing, as are human populations. Therefore, refuges offer a way to address both ecological and social challenges simultaneously, enhancing biodiversity and human well-being. [Display omitted] [ABSTRACT FROM AUTHOR]

The jumping spider Marpissa marina (Goyen, 1892) is endemic to Aotearoa New Zealand. In this paper, we redescribe the species. Marpissa marina was placed in the Northern Hemisphere genus Marpissa due to its subjective similarity to spiders in that genus. The original description lacked modern morphological diagnoses and useful illustrations. The description was based largely on the female, and therefore lacked the taxonomically important characters seen in the male pedipalp. Previous literature has suggested M. marina may be related to the Australian genus, Maratus Karsch, 1878. We applied an integrative taxonomic approach based on diagnostic morphological characters and molecular analysis for a more detailed species description and assignment into an appropriate genus. Morphological features indicate that M. marina belongs to Maratus. This is supported by phylogenetic analyses using DNA sequences from the nuclear gene Actin 5C and the mitochondrial gene 16S ribosomal RNA. We transfer Marpissa marina into the genus Maratus, as Maratus marinus (Goyen, 1892), new combination. [ABSTRACT FROM AUTHOR]

Arthropods may make a significant fraction of the total number of soil organisms. They function as plant litter transformers or ecosystem engineers, and thus contribute positively to soil health. The present study was conducted during the 2020--2022 at International Rice Research Institute, South Asia Regional Centre, Varanasi. Study investigates the impact of different farming methods- conventional (Scenario 1; Sc1), LINF- Low-input natural farming (Sc 2); BBEF- Biochar-based ecological farming (Sc 3); CROF- Climate-resilient organic farming (Sc 4); RF- Regenerative farming (Sc 5) practices on soil arthropod populations in rice-wheat systems. Study utilized pitfall traps across various experimental setups. The findings revealed a significant increase in arthropod diversity and abundance, particularly in organic farming scenarios, where the Formicidae family (ants) and the Araneae family (spiders) were most prevalent. In an organically rich soil system, the five most diverse groups (Isopoda, Myriapoda, Insecta, Acari, and Collembola) were reported. This increase can be attributed to the nutrient-rich amendments that positively influence soil organisms. This study highlights a gradual increase in specific taxa, such as cockroaches, spiders, ants, and grasshoppers, following the transition to organic farming. Principal component analysis (PCA) further revealed distinct arthropod distribution patterns in the different farming systems, indicating the unique ecological impact of each method. Interestingly, predator populations in zero-till wheat fields under regenerative agriculture were greater than those in conventionally tilled fields. These results underscore the substantial role of organic and regenerative farming practices in promoting sustainable agricultural ecosystems. This study reveals the complex interplay between farming practices and arthropod dynamics and highlights the ecological benefits of sustainable agricultural methods, emphasizing their potential to enhance biodiversity and ecosystem health. [ABSTRACT FROM AUTHOR]

Consumers are thought to select food resources based on their nutritional content. While laboratory experiments have explored this, the nutritional dynamics of invertebrate predators have been scarcely studied in the field given various methodological constraints. The intersection of these nutritional dynamics with predator traits is also poorly characterised, leading to many gaps in our understanding of how different predators forage and feed in natural systems. Here, we integrate dietary metabarcoding with prey macronutrient (protein, lipid and carbohydrate) content and abundance to assess how nutrients and predator traits (sex, life stage and taxonomy) interactively drive prey preferences in the field, using spider–prey interactions as a model system. Different spider genera, sexes and life stages had nutritionally distinct diets. Our analyses demonstrated disproportionate foraging (selection and avoidance) for prey rich in different macronutrients, with the nature of these relationships differing between spider taxa, life stages and sexes. This may be explained by niche differentiation among spider groups, driven by biases toward prey rich in different nutrients, or nutrient‐specific foraging in which individual spiders vary their nutritional preferences to redress deficits, although further evidence is required to confirm this. This insight into the nutritional dynamics of generalist invertebrate predators extends our understanding beyond lab‐based behavioural assays and provides a novel framework for other complex real‐world systems. [ABSTRACT FROM AUTHOR]

ABSTRACT Spiders are a hyperdiverse taxon and among the most abundant predators in nearly all terrestrial habitats. Their success is often attributed to key developments in their evolution such as silk and venom production and major apomorphies such as a whole‐genome duplication. Resolving deep relationships within the spider tree of life has been historically challenging, making it difficult to measure the relative importance of these novelties for spider evolution. Whole‐genome data offer an essential resource in these efforts, but also for functional genomic studies. Here, we present de novo assemblies for three spider species: Ryuthela nishihirai (Liphistiidae), a representative of the ancient Mesothelae, the suborder that is sister to all other extant spiders; Uloborus plumipes (Uloboridae), a cribellate orbweaver whose phylogenetic placement is especially challenging; and Cheiracanthium punctorium (Cheiracanthiidae), which represents only the second family to be sequenced in the hyperdiverse Dionycha clade. These genomes fill critical gaps in the spider tree of life. Using these novel genomes along with 25 previously published ones, we examine the evolutionary history of spidroin gene and structural hox cluster diversity. Our assemblies provide critical genomic resources to facilitate deeper investigations into spider evolution. The near chromosome‐level genome of the ‘living fossil’ R. nishihirai represents an especially important step forward, offering new insights into the origins of spider traits. [ABSTRACT FROM AUTHOR]

Electroreception is the capacity of living organisms to detect the presence of electricity, usually studied in the aquatic environment. Electroreception in air, however, has received much less attention until relatively recently. Understanding how and why aerial electroreception may work requires a multidisciplinary framework, anchored in both the physics of static electricity and the ecology of sensory biology. In essence, the novel challenge arises from the fact that air is a much less conductive medium than water. Yet, recent research on terrestrial arthropods, including bees, flies, spiders, worms and caterpillars, has unveiled sensitivity to electric fields in different sensory ecological contexts. For each aerial organism considered thus far, filiform hairs and/or the antennae have been proposed to be the specialised sensory structures enabling detection based on both empirical and theoretical evidence. This newfound sensory modality reveals a previously unrecognised source of information, a new informational ecological niche integral to diverse life histories and navigational abilities, which remarkably involves animals, plants and atmospheric electricity (Figure 1). Understanding aerial electroreception in arthropods opens avenues for exploring their behaviour and ecology in diverse environments and sheds light on the evolution of sensory adaptations in terrestrial organisms. Because, as is known today, humans are not sensitive to weak electric fields, challenges arise in our comprehension of the elusive and discrete nature of aerial electric fields, and how they could be detected and used by terrestrial organisms. Daniel Robert introduces aerial electroreception, a sensory modality documented in terrestrial arthropods, such as bees and spiders, that is based on electrostatic charging, and operates in the contexts of plant–pollinator and predator–prey interactions, as well as in dispersal and phoretic behaviours. [ABSTRACT FROM AUTHOR]

The definition of species boundaries in mygalomorph spiders is historically based on morphological characters, which can be problematic due to the homogeneous morphology and continuous variation across species. The male copulatory bulb of Neodiplothele, as of many mygalomorphs, is phenotypically diverse and the differences are displayed mostly by subtle shape variations. The purpose of this research was to evaluate the traditional morphology-based delimitation of species informal groups and assess the significance of morphological characters in the systematics of the highly variable and widespread mygalomorph spiders of the barychelid genus Neodiplothele. We conducted a geometric morphometric analysis on the bulb of specimens of Neodiplothele using Fourier descriptors. The results show that the bulb is rather difficult to apply as a discrete character in a taxonomic context and show the proximity of a group of undescribed species of Neodiplothele to both groups proposed in a previous revision, indicating a continuous variation. As a taxonomic character, the use of the copulatory bulb shape as a discrete character may be uninformative in the case of species that present one or more intermediate states, when the incorrect treatment of the character can result in a misrepresentation of shape diversity and equivocate inference of evolutionary relationships.https://zoobank.org/urn:lsid:zoobank.org:author:471C6BE5-D24C-4805-B2DE-EB89B6D1D8FAhttps://zoobank.org/urn:lsid:zoobank.org:author:D4955FF5-FE7F-4E68-AB2F-4A89593F9850 [ABSTRACT FROM AUTHOR]

Spiders are an abundant group of natural enemies preying on insect pests in agroecosystem. But their potential in biological control has not been fully realized due to difficult mass production. One hindrance is the intense intraspecific aggression in spiders. Neurotransmitters such as serotonin play important roles in modulating aggression. Here, we investigated the regulatory function of serotonin (5‐hydroxytryptamine [5‐HT]) signaling in the intraspecific aggression in a wandering spider Pardosa pseudoannulata (Araneae, Lycosidae). The aggression was quantified with 5 escalated aggression behaviors as approach, chasing, lunging, boxing, and biting. Virgin (VG) females exhibited higher aggression levels but less 5‐HT content than post‐reproductive (PR) females. Systemic increase of 5‐HT via 5‐HT injection decreased aggression, while decrease of 5‐HT via RNA interference (RNAi) of the tryptophan hydroxylase gene, increased aggression. The involvement of the four 5‐HT receptors were determined via individual or combined RNAi. Co‐RNAi of the three 5‐HT1 genes increased overall aggression with decreased incidents of approach, chasing, lunging, and increased biting. RNAi of 5‐HT1B decreased approach and increased biting, whereas RNAi of 5‐HT1A or 5‐HT1C did not affect aggression. RNAi of 5‐HT7 decreased approach only. Therefore, different 5‐HT receptor types contribute to different aspects of the inhibitory effects of 5‐HT on aggression and provide several pharmacological targets for manipulating spider aggression. 5‐HT injection did not affect spiders’ predation on their insect prey, the brown planthopper Nilaparvata lugens. The findings reveal 1 neuronal mechanism regulating intraspecific aggression in spiders and provide an insight in developing aggression suppression strategies for spider mass rearing. [ABSTRACT FROM AUTHOR]

The Rapoport Effect is a macroecological approach that proposes to explain the trend of species distribution across environmental gradients. Here, edaphic spiders were chosen as a model organism to test the Rapoport Effect along an elevational gradient in a ‘Brejo de Altitude’ in the Baturité Massif, Northeast Brazil. Spiders were sampled during 13 months from August 2020 to August 2021 using pitfall traps in five elevational bands distributed along the Baturité Massif. A total of 1,476 individuals were collected, of which adults correspond to 1,171 individuals, belonging to 107 morphospecies from 29 families. A tendency was observed in the decrease of species richness as a function of the increase in altitude, except in the two higher bands. We also found that 26 morphospecies present maximum elevational amplitude (740 m). Our results provide support for the occurrence of the Rapoport Effect in edaphic spiders along the elevational gradient in Baturité Massif. [ABSTRACT FROM AUTHOR]

Characterization of fungal spider pathogens lags far behind their insect counterparts. In addition, little to nothing is known concerning the ecological reservoir and/or fungal entomopathogen community surrounding infection sites. Five infected spider cadavers were identified in the neo-tropical climate of north-central Florida, USA, from three of which viable cultures were obtained. Multi-locus molecular phylogenetic and morphological characterization identified one isolate as a new Gibellula species, here named, Gibellula floridensis, and the other isolates highly similar to Parengyodontium album. The fungal entomopathogen community surrounding infected spiders was sampled at different habitats/trophic levels, including soil, leaf litter, leaf, and twig, and analyzed using ITS amplicon sequencing. These data revealed broad but differential distribution of insect-pathogenic fungi between habitats and variation between sites, with members of genera belonging to Metarhizium and Metacordyceps from Clavicipitaceae, Purpureocillium and Polycephalomyces from Ophiocordyceps, and Akanthomyces and Simplicillium from Cordycipitaceae predominating. However, no sequences corresponding to Gibellula or Parengyodontium, even at the genera levels, could be detected. Potential explanations for these findings are discussed. These data highlight novel discovery of fungal spider pathogens and open the broader question regarding the environmental distribution and ecological niches of such host-specific pathogens. [ABSTRACT FROM AUTHOR]

Maternal care is critically important for the survival of offspring in various animals. Spiders in the family Lycosidae are known for their hunting ability and maternal care behaviors. Predation on newly hatched spiderlings (pulli) by mother spiders decreases when they come into contact, and they carry the pulli on their dorsal surface. However, the factors inducing maternal care in lycosid spiders have not been elucidated. In this study, we investigated maternal care in Pardosa pseudoannulata (Araneae, Lycosidae) females. We proposed that the physical interaction between pulli and mother spiders induces maternal care via m‐aminophenylacetylene (m‐A), a novel regulator of maternal care. The presence of pulli on the dorsal abdomen of non‐mother spiders suppressed pulli predation and increased the pulli‐carrying rate, and the absence of pulli on the mother spiders increased pulli predation and decreased the pulli‐carrying rate. The compound m‐A was abundant in mother spiders, and it could be induced in non‐mother spiders when they carried pulli. The topical application of m‐A to non‐mother spiders and m‐A injection decreased pulli predation and increased the pulli‐carrying rate, respectively; these findings indicate that m‐A in both internal tissues and the integument is required for the induction of maternal care behavior, and the interaction between pulli and females induces the production of m‐A. In‐depth study of the regulatory mechanism of maternal care will enhance our understanding of spider biology and behavior. [ABSTRACT FROM AUTHOR]

Background: The sea spiders (Pycnogonida Latreille, 1810) of the Hunsrück Slate (Lower Devonian, ~400 million years ago) are iconic in their abundance, exquisite pyritic preservation, and in their distinctive body plan compared to extant sea spiders (Pantopoda Gerstäcker, 1863). Consequently, the Hunsrück sea spiders are important in understanding the deep evolutionary history of Pycnogonida, yet they remain poorly characterised, impacting upon attempts to establish a time-calibrated phylogeny of sea spiders. Methods: Here, we investigated previously described and new material representing four of the five Hunsrück pycnogonids: Flagellopantopus blocki Poschmann & Dunlop, 2006; Palaeoisopus problematicus Broili, 1928; Palaeopantopus maucheri Broili, 1929; and Pentapantopus vogteli Kühl, Poschmann & Rust, 2013; as well as a few unidentified specimens. Using X-ray microtomography and Reflectance Transformation Imaging, we describe new fossils, provide evidence for newly revealed anatomical features, and interpret these data in comparison to extant species. We also reinterpret the previously published illustration of the (probably lost) holotype of Palaeothea devonica Bergström, Stürmer & Winter, 1980. Results: We provide the first detailed description of the cephalic appendages of Palaeoisopus problematicus and revise the interpretation of the organisation of its ocular tubercle. Furthermore, we provide new insights into the structure of the legs and the proboscis of Palaeopantopus maucheri, the first description of the body of Flagellopantopus blocki and describe a new specimen of Pentapantopus vogteli, demonstrating that it had eight legs, in contrast to previous interpretations. We argue that, contrary to previous suggestions, Palaeothea devonica probably had a different body plan from extant pantopods. We discuss the ecological traits of the Hunsrück pycnogonids based on their morphological adaptations, and conclude that there is no compelling evidence of Pantopoda in the Devonian. Through comparative interpretation of the legs as well as general morphology, we can divide the Hunsrück pycnogonids into two morphological groups, while Pantopoda constitutes a third morphological group. [ABSTRACT FROM AUTHOR]

At high latitudes, where the sun does not set over the horizon for a significant part of the summer, living organisms cannot regulate diurnal rhythms on the basis of photoperiod. In such regions, are other factors acting as zeitgebers or are the animals in these regions arrhythmic? The objectives of this study were to determine whether diurnal rhythms of locomotor activity are pronounced in model groups of terrestrial arthropods under natural conditions of constant light and to determine whether factors such as light, temperature, humidity, and wind influence this activity. Using pitfall traps, we have studied the diurnal activity of springtails, soil mites, dipterans, spiders, and beetles on Shokalsky Island, Kara Sea, Western Siberia (72.92°N 74.33°E). It was revealed that the continuous light regime in the Arctic does not eliminate the daily periodicity of activity of terrestrial arthropods. Periodicity was observed both at the whole community level and at the level of model groups and species. For the majority of the taxa studied, there was a daily peak of activity that occurred in the first half of the day. The general rhythm observed in different taxonomic groups indicates that the activity is regulated by some external factors. Although the rhythms identified apparently correlate with light level, temperature, and thermal preference, it remains difficult to determine the leading factor driving activity in the field. [ABSTRACT FROM AUTHOR]

The open ecosystem (e.g. grasslands, prairies, shrublands) tends to be ecologically less stable than closed one (i.e. forests) and encompassess higher spatial heterogeneity in terms of environmental diversity. Such differences are expected to differentially constrain the diversity and structure of the communities that inhabit each of them, but identifying the specific processes driving contrasting biodiversity patterns between open and closed systems is challenging. In order to understand how environmental variability might structure spider assemblages, both between and within open and closed ecosystems, we implement a high throughput multiplex barcode sequencing approach to generate a dataset for 8585 specimens representing 168 species, across the open ecosystem within the Canary Islands. Combining these with spider sequences from the closed ecosystem within the same islands, we show that spider communities in the open ecosystem show higher species richness, higher beta diversity, and higher proportions of rare species but proportionately lower numbers of endemic species than communities in the closed ecosystem. We furthermore assess if environmental heterogeneity and habitat stability are the major drivers of such differences by assessing spatial genetic structuring and the influence of bioclimatic variables. Our results point to environmental heterogeneity rather than stability as a major driver of spatial patterns between open and closed ecosystems. [ABSTRACT FROM AUTHOR]

Oil palm plantations are typically managed in a monoculture system over large areas. This system contributes to biodiversity loss and promotes pest outbreaks by reducing natural enemies. However, ecosystem functions in oil palm plantations vary spatially and temporally and can still support biodiversity under certain conditions.We conducted a study on the species richness, abundance and species composition of natural enemies in oil palm plantations and investigated the factors influencing natural enemy communities in oil palm plantations at both local and landscape scales. We selected 12 sites in an oil palm plantation in Central Borneo, Indonesia, which were grouped into 4 sub‐areas based on the presence of natural habitats, which varied in local and landscape characteristics. Arthropods were sampled using canopy knockdown fogging with a pyrethroid insecticide.Different taxa of natural enemies responded differently to changes in habitat characteristics within oil palm plantations. Species richness of spiders was not affected by either local or landscape scale, but their species composition was affected by oil palm tree age (local scale) and the total edge of dominant oil palm tree age (landscape scale). Ant species richness was influenced by the class area of natural habitat (landscape scale), whereas their species composition was not influenced by either local or landscape scale. On the other hand, species richness of parasitoid wasps was influenced by light intensity (local scale) and the variation of oil palm tree age within a landscape (landscape scale). However, their species composition was only affected by light intensity.The results suggest that oil palm management practices need to consider both local and landscape scales to maintain biodiversity and biological control and to achieve sustainable management of oil palm plantations. [ABSTRACT FROM AUTHOR]

Although urbanisation is one of the greatest threats to biodiversity, its effect on particular invertebrate groups remains ambiguous on local and landscape scales.We aimed to analyse the effect of urban grassland management on spiders (Araneae) and carabids (Coleoptera: Carabidae), as well as other local and landscape parameters. We investigated 27 grasslands of two different management intensities ('extensive': one to two late cuts with removal of biomass [n = 18]; 'intensive': three to five mulching cuts [n = 9]) in the city of Karlsruhe, Germany. Pitfall trapping and sweep netting were performed to sample carabids and spiders.Results indicate that urban grasslands in Karlsruhe are inhabited by species‐rich assemblages, including several species of conservation concern (cc). Latter remain mostly restricted to dry grassland. The number of total specimens and of those belonging to species of cc were negatively affected by intensive management. The number of specimens of species of cc further decreased with increasing humidity and in spiders, additionally, by vegetation height. Landscape factors had limited effects, and only isolation of meadows negatively influenced the species richness of carabids (total and of species of cc).Our results demonstrate that conservation of dry grasslands in urban areas is crucial for sustaining local arthropod communities. Dry urban grassland may also act as a refugium for species of cc and mitigate the global insect crisis on a local and regional scale. In conclusion, biodiversity‐friendly mowing regimes should be applied on a broader scale in urban areas and target especially dry grassland plots. In addition, increasing connectivity and permeability of the urban matrix assist the colonisation by species of cc. [ABSTRACT FROM AUTHOR]

The jumping spider species Gedea pinguis Cao & Li, 2016 is newly recorded from Vietnam and redescribed based on the sole male specimen. A detailed redescription, illustrations of the copulatory organs, and somatic features, along with an updated distribution map are provided. DNA barcode derived from the mitochondrial cytochrome c oxidase subunit I (COI) gene of the species G. pinguis from Vietnam is also included for future use and to compare the genetic distances with Gedea cf. tibialis Zabka, 1985 from Malaysia. With the addition of a new record, the genus Gedea Simon, 1902 in Vietnam now reaches 3 species, but doubts arise regarding the conspecificity of the two opposite sex species, Gedea tibialis Żabka, 1985 (male) and Gedea typica (Żabka, 1985) (female), as they share the same type locality. Additionally, a dichotomous key to all Gedea species is also given in this study. [ABSTRACT FROM AUTHOR]

Falconina cafetera sp. nov. (Araneae, Corinnidae) is described based on specimens of both sexes. Specimens were collected in shaded coffee agro-ecosystems and in a suburban cacao orchard in Chiapas, Mexico. This new species is the first Falconina recorded from Mexico and the northernmost species of the genus in continental America, with the exception of F. gracilis (Keyserling, 1891) introduced to the USA and Cuba. F. cafetera sp. nov. differs from all other Falconina species by having most of its opisthosoma light-colored with some dark patches and by the characteristics of the male palp and female epigynum. Observations are included about one sclerite found in the male palp of this species, not mentioned for other species in this genus. The key of Falconina species by García and Bonaldo (2023) is modified to include this species. Furthermore, field observations and laboratory rearing of juveniles indicate that F. cafetera sp. nov. spiders are able to feed on ants. [ABSTRACT FROM AUTHOR]

The species Xysticus lendli is known only from its original description of a single male and one doubtful record so far. Here, we illustrate and redescribe the species based on 34 specimens in total and describe its female for the first time. We illustrated the male palp via compound micrographs and scanning electron micrographs. We generated a DNA barcode and placed it into a current phylogenetic scaffold to confirm the species' placement of Spiracme, a long-debated sister- or subgroup of Xysticus; hence, a new combination of Spiracme lendli (Kulczyński, 1897), comb. nov. is proposed. We illustrated the visually similar Xysticus mongolicus and the type species of Spiracme, S. striatipes, and compared them to S. lendli to aid future distinctions between those species. [ABSTRACT FROM AUTHOR]

A new monotypic genus, Pamirosa gen. nov. with the type species P. kudratbekovi sp. nov. (♂♀), is described from Pamir Mountains in eastern Tajikistan. The new genus represents the first record of the mainly Austrolasian subfamily Artoriinae Framenau, 2007 in Central Asia. It differs from all known genera of Artoriinae, as well as from all other lycosids, by having a unique spiraled embolus and epigyne with screw-shaped membranous copulatory ducts unknown in other wolf spiders. The new species was collected among stone screes at an elevation of 4700 meters. Unlike all other Palaearctic lycosids inhabiting stony screes and possessing four or more pairs of ventral tibial spines on leg I, Pamirosa gen. nov. has only three pairs. Description, figures, diagnosis of the new species, and a photograph of its habitat are provided. Additionally, the distribution of scree-dwelling Lycosidae in Asia is discussed. [ABSTRACT FROM AUTHOR]

Parasitoid larvae consume their hosts to obtain the nutritional resources required for their development. Parasitoid wasps can optimally select the size of their hosts by laying unfertilized and fertilized eggs according to the amount of biomass available for consumption by the larvae. However, parasitoids may eventually experience low host availability within the optimal range of body sizes, affecting the survival of their offspring. In this study, we identified a situation in which all available hosts (Leucauge volupis) were smaller than those previously observed to be parasitized by Hymenoepimecis pinheirensis at the same study site. Therefore, we investigated how these parasitoids can bypass the scarcity of ideal hosts. Female wasps biased their oviposition toward the largest L. volupis females available. In this suboptimal scenario, they did not oviposit only unfertilized eggs, which developed into relatively small offspring (males). In this situation, they lay fertilized eggs mainly on larger spiders. Larval mortality was high, but the larvae attached to the larger spiders were more likely to complete their development. In general, H. pinheirensis females managed to target the best hosts available but could not delay the oviposition of fertilized eggs or avoid offspring mortality. Here, we discuss the potential causes of asynchronies in the life cycles of parasitoid wasps and their hosts, the availability of optimal hosts, and how these factors may affect their populations. [ABSTRACT FROM AUTHOR]

A new monotypic genus of Prodidominae, Paleotoca gen. n., is proposed to include one cave species collected in a paleoburrow and ferruginous caves from Quadrilátero Ferrífero, Minas Gerais, Brazil: Paleotoca diminassp. n. (♂♀). The new genus is closely related to other Neotropical Prodidominae by sharing the classic claw tuft clasper. Paleotoca gen. n. is diagnosed by the absence of a dorsal abdominal scutum, a ventral parallel rows of strong spines on the tibia and metatarsus I–II, a lack of a conductor, a discrete median apophysis on the bulb and a bifid retrolateral tibial apophysis in the male palp, a posterior extension that is beak-shaped, and folds of a copulatory duct ventrally visible in the female epigyne. Like other Prodidominae species from caves, P. diminassp. n. is a troglobitic spider with morphological characteristics that indicate specialization to live in subterranean environments, including reduction in cuticular pigments, eye loss, heavy spination and trichobothria. [ABSTRACT FROM AUTHOR]

Local microgeographic sites subdivided by sharp ecological and climatic contrasts are important platforms for measuring biodiversity patterns and inferring the possible effect of climatic and ecological variables on species distributions and habitat use. Here, we report results from 24 months (September 2019–August 2021) of continuous pitfall trapping collection in Lower Nahal Keziv, Western Upper Galilee, Israel ("Evolution Canyon" II (hereafter—EC II)). This site receives an average annual rainfall of 784 mm and contains two slopes that differ markedly by solar radiation and plant formation. The first is the south-facing slope (SFS), which is characterized as a semiarid garrigue and open grassland. The second is the contrasting north-facing slope (NFS), which is characterized by a more humid East Mediterranean forest. The slopes are separated by a narrow valley bottom (VB). Analysis of ca. 1750 arachnid specimens, collected from 70 pitfall traps along the slopes and valley, indicates significantly different arachnid assemblages between the NFS and SFS, likely due to the differences in solar radiation that affect plant-cover percentage, which in turn affects the arachnid assemblage composition. In addition to 98 arachnid taxa collected and identified to species and morphospecies level, this study resulted in the discovery of two species new to science, which are described as part of this publication (100 arachnid species and 11 additional taxa that were not identified to species, a total of 111 taxa). Our study, moreover, contributes new ecological data on the spatial and temporal distribution of arachnids, and therefore attests to the importance of year-round sampling in an understudied region. Overall, our study enables a better understanding of arachnid diversity and their distributions and serves as a reference for future research aimed at testing the effect of climate change and other environmental factors that influence arachnid assemblages in natural habitats. [ABSTRACT FROM AUTHOR]

Resource subsides can link aquatic and terrestrial ecosystems. Animals that emerge from aquatic ecosystems can transport nutrients that are scarce in terrestrial environments, like long-chain polyunsaturated fatty acids (LC-PUFA), which are synthesized by algae in aquatic environments. LC-PUFAs have critical roles in animal physiology and are precursors to eicosanoids, which help mediate immune responses. We previously found that wolf spiders in wetland ecosystems had higher levels of LC-PUFA and stronger immune responses than nearby upland spiders. However, we could not determine if the stronger immune responses were because of eicosanoids derived from LC-PUFA subsidies or because they had a larger resource pool from aquatic prey subsidies. Here, we use 2 immune assays, 1 affected by eicosanoids and 1 not affected, to differentiate between those 2 possibilities. We fit generalized linear mixed models and found that LC-PUFA subsidies are responsible for the stronger immune responses in wetland spiders. We also found evidence that wolf spiders maintain some immune responses across reproductive states and increase other immune responses when they are gravid. Our results demonstrate that LC-PUFA subsidies can alter immune function in recipient consumers because LC-PUFAs are preferentially stored rather than used as energy. This alteration of immune function could have consequences for disease transmission and pathogen abundance in linked aquatic and terrestrial ecosystems. [ABSTRACT FROM AUTHOR]

Jumping spiders (Salticidae) are a diverse group of non‐web‐building predators and the most species‐rich spider family. The Salticidae Tribe Nannenini consists of a small group of Oriental jumping spiders that are very poorly known. The use of explicit phylogenetic analyses to establish its affinities has so far remained limited. The Nannenini genus Epidelaxia has a peculiar morphology, making its systematic position uncertain. In this study, we present a comprehensive dataset combining molecular and morphological data for Nannenini, including exemplars from all genera. This dataset comprises DNA sequences of approximately 2400 bp, including nuclear genes (18S, 28S and H3) and the mitochondrial gene CO1, sequenced for 40 taxa (20 ingroups and 20 outgroups), along with 61 morphological characters. Notably, both DNA sequences and morphological traits were analysed separately and concurrently for the first time. The Nannenini clade is recovered with high support. Further, Epidelaxia is monophyletic and sister to Tubalaxia gen. n. This is the first hypothesis on the internal phylogenetic structure of Epidelaxia and its placement within the Tribe Nannenini. A new genus Tubalaxia gen. n. and the following new species are described: E. bharathi sp. n., E. somasundaram sp. n., T. castanea sp. n., T. aurea sp. n. The following new combination is proposed: Tubalaxia minuta (Prószyński, 1992) comb. n. Epidelaxia albostellata, E. albocruciata and E. obscura are redescribed. It is worth noting that the newly described species face endangerment due to their limited distribution and small population sizes. [ABSTRACT FROM AUTHOR]

The genus Haplodrassus Chamberlin, 1922 is reported for the first time from Pakistan. The new species Haplodrassus nagri sp. n. is described and illustrated from Dir Lower. [ABSTRACT FROM AUTHOR]

Background: Sinamma Lin & Li, 2014 is a small tetrablemmid genus distributed in China, with three currently known species: Sinamma oxycera Lin & Li, 2014 from Guangxi Zhuang Autonomous Region and S. quadrata Tong & Li, 2022 and S. yingae Tong & Li, 2022 from Guangdong Province. New information: While examining spider specimens obtained by sifting leaf litter from Danxiashan National Nature Reserve in Guangdong Province of China, we discovered a new species of the genus Sinamma, S. danxia sp. nov., which is described here. [ABSTRACT FROM AUTHOR]

The new data on the distribution and bioecological features of 42 species included in the regional Red Data Book have been obtained. These are 37 species of insects, three species of arachnids and two species of gastropods. For 17 species, the data on their distribution in the region turned out to be fundamentally new. Seven studied species are represented in the Red Data Book of the Russian Federation and 36 species in the Red Data Books of other subjects of the Russian Federation. The driving factors of negative impact on the populations of many species are the following: a) intensive, sometimes continuous logging and forest fires, b) large-scale and intensive use of pesticides by farmlands and on the adjacent territories, c) significant recreational load on typical habitats of rare species, d) death of many invertebrates on dirt roads caused by motor vehicles of tenants, hunters, producers of biological products, etc. e) unregulated grazing of livestock, running of horses’ herds, organization of new farmlands and their further active exploitation, as well as fires in the steppe zone. The most vulnerable and sensitive to anthropogenic influence species include Carabus hungaricus, Argyronom laodice, Clossiana thore, Crebeta deidamia, Neolysandra coelestinus, Bombus armeniacus, B. fragrans, B. pratorum and B. veteranus. The state of populations of Parnassius apollo, Bombus terrestris, B. serrisquama, Bombyllus major, Laphria gibbosa and Allohogna singoriensis is not particularly alarming. In our opinion, Anax parthenope, Dendroxena quadrinaculata, Mycetina cruciata, Chelis dahurica, Eresus kollari and Hirudo medicinalis deserve to be listed in the third edition of the Red Data Book of Chelyabinsk Oblast in category III or IV.

An updated checklist of faunal biodiversity of the spiders, in two norther states of India, Uttar Pradesh and Uttarakhand is presented herewith. A total of 520 species of spiders described under 236 genera belonging to 50 families were recorded in both the states of north India. The biodiversity of spiders is more in Uttar Pradesh (284 species, 146 genera, 36 families) than Uttarakhand (373 species, 202 genera, 45 families). However, most of the areas in both the states are still virgin regarding the faunal survey programmes and need intensive and extensive survey in those areas by enthusiastic workers.

Spiders contribute significantly to natural pest control in agriculture. Here, we investigated the biodiversity, population dynamics and predatory activities of spiders in the maize-growing districts (Kasur and Lahore) of Punjab, Pakistan during 2018–2019. Various collecting methods including pitfall and yellow pan traps, manual hand-picking, beat sheet, and sweep nets were used to collect spiders on a biweekly basis. The collected 12,894 individuals represented 45 different species, 27 genera, and 13 families. The major families recorded were Araneidae (32.92%), Lycosidae (20.43%) and Salticidae (11.12%) comprising >64% of the overall abundance. Neoscona theisi (Araneidae) was found to be most dominant species (11.61%). Moreover, the species Macracantha hasselti (Araneidae) and Atypena formosana are reported for the first time from Pakistan. Besides, the estimated species diversity from both districts was 97%. The Margalef's index was highest in Kasur (D = 5.08) and lowest in Lahore (D = 4.95). The values of the Shannon-Wiener and species evenness indices were similar in Kasur and Lahore suggesting similar diversity levels and an even distribution. Spider abundance was highest in April and lowest in June and July. These findings will help to develop effective Integrated Pest Management strategies in maize growing areas across the world.

Women remain underrepresented in most math-intensive fields. [Breda and Napp, Proc. Natl. Acad. Sci. U.S.A. 116, 15435 (2019)] reported that girls' comparative advantage in reading over math (i.e., the intraindividual differences between girls' reading vs. math performance, compared to such differences for boys) could explain up to 80% of the gender gap in students' intentions to pursue math-intensive studies and careers, in conflict with findings from previous research. We conducted a conceptual replication and expanded upon Breda and Napp's study by using new global data (PISA2018, N = 466,165) and a recent US nationally representative longitudinal study (High School Longitudinal Study of 2009, N = 6,560). We coded students' intended majors and careers and their actual college majors. The difference between a student's math vs. reading performance explained only small proportions of the gender gap in students' intentions to pursue math-intensive fields (0.4 to 10.2%) and in their enrollment in math-intensive college majors (12.3%). Consistent with previous studies, our findings suggest girls' comparative advantage in reading explains a minority of the gender gap in math-related majors and occupational intentions and choices. Potential reasons for differences in the estimated effect sizes include differences in the operationalization of math-related choices, the operationalization of math and reading performance, and possibly the timing of measuring intentions and choices. Therefore, it seems premature to conclude that girls' comparative advantage in reading, rather than the cumulative effects of other structural and/or psychological factors, can largely explain the persistent gender gap in math-intensive educational and career choices.

In the present study, we investigate how spiders can be used to assess the effectiveness of restoring mesic grasslands on former urban lawns. We compile and analyze a comprehensive dataset, including both past and current data, focusing on the Aachen region. By systematically examining this data, we identify various indicators using different analytical methods. This approach allows us to distinguish distinct species communities, making them useful as diagnostic tools at various stages of habitat development. Additionally, we identify further parameters that are essential for evaluating meadow restoration in urban settings. We highlight the crucial importance of understanding the local species repertoire, as this knowledge is vital for setting realistic benchmarks for restoration projects. [ABSTRACT FROM AUTHOR]

The Laufeia clade is a peculiar lineage of euophryine jumping spiders showing rapid divergence of male genital structures, especially the embolic complex that directly interacts with female genitalia during sperm transfer. With the rapid growth of species discovery and the perplexing morphology of male genitalia in the Laufeia clade, the controversy in its classification has become a crucial problem. In this study, we applied a phylogenomic approach using ultra‐conserved elements data to infer the phylogeny of the Laufeia clade with extensive taxon sampling. A comparative morphological study was performed to evaluate diagnostic characters and understand the evolution of the male embolic complex within the Laufeia clade. The evolution of microhabitats (foliage, tree trunk, rock and surface litter) was also investigated to uncover the potential link between the microhabitat shifts and male embolic complex divergence. The results provide a strongly supported phylogenetic framework and updated generic concepts for the Laufeia clade. The synapomorphies for the updated genera within the Laufeia clade were identified through character mapping on the phylogeny. Ancestral state reconstruction analyses revealed that the Type I embolic complex (characterized by a disc‐like embolic disc with a lamina as its outer edge) was ancestral and gradually evolved into the Type II (without lamina of embolic disc, base of embolic complex often modified into a functional "conductor") and Type III (lacking lamina of embolic disc and base of embolic complex) embolic complex, and that some embolic shapes evolved multiple times independently in different lineages of the Laufeia clade. The shift from foliage‐dwelling to tree trunk‐dwelling in the common ancestor of the Laufeia clade may have facilitated the divergent evolution of male embolic complex in the Laufeia clade. This study provides a solid foundation for future studies of systematics and evolution of this group. [ABSTRACT FROM AUTHOR]

Recent, rapid arthropod declines have been tied to human activity. Yet, the propensity for human‐produced noise to disturb the substrate‐borne (vibratory) channel remains virtually untested despite arthropods' ubiquitous use of vibratory information. Characterizing the vibratory landscape at biologically relevant scales is an essential initial step. We aimed to measure vibratory noise across space and time to assess its potential overlap with the urban–rural range and season of a funnel‐weaving spider, Agelenopsis pennsylvanica (C.L. Koch) (Araneae: Agelenidae), a common urban arthropod. We assessed 24‐h ambient vibrations (hereafter vibratory "noise") at 23 sites across urban–rural Lincoln, Nebraska (NE, USA), during the adult season of A. pennsylvanica (August–October). Vibratory noise (amplitude, Leq) varied by ~15 dB across sites overlapping with frequencies within A. pennsylvanica's sensitivity (20–1000 Hz). Urban vibratory noise was positively correlated with the principal component containing estimates of traffic‐induced vibrations (e.g., traffic volume, road proximity, and impervious cover), whereas rural noise levels correlated with probable harvest times. Our findings indicate spatial variation in noise in urban areas and seasonal noise variability in rural areas. We also tested how A. pennsylvanica—collected from four distinct noise survey sites—use their vibratory microhabitat. We assessed daily spider position and dry silk mass within a microcosm that played loud and quiet vibrations (white noise differing by ~15 dB) in separate but connected chambers. Age affected the chamber choice (hereafter "microhabitat use") of spiders collected from the loudest site, as younger adults associated with and used more silk in the loud chamber, but this effect decreased with age. As our data demonstrate that vibratory noise varies with A. pennsylvanica's microhabitat and season with a high potential for impacting behavior, we hypothesize that this environmental noise likely impacts other arthropods as well. [ABSTRACT FROM AUTHOR]

Venom represents a key adaptation of many venomous predators, allowing them to immobilise prey quickly through chemical rather than physical warfare. Evolutionary arms races between prey and a predator are believed to be the main factor influencing the potency and composition of predatory venoms. Predators with narrowly restricted diets are expected to evolve specifically potent venom towards their focal prey, with lower efficacy on alternative prey. Here, we evaluate hypotheses on the evolution of prey‐specific venom, focusing on the effect of restricted diet, prey defences, and prey resistance. Prey specificity as a potential evolutionary dead end is also discussed. We then provide an overview of the current knowledge on venom prey specificity, with emphasis on snakes, cone snails, and spiders. As the current evidence for venom prey specificity is still quite limited, we also overview the best approaches and methods for its investigation and provide a brief summary of potential model groups. Finally, possible applications of prey‐specific toxins are discussed. [ABSTRACT FROM AUTHOR]

Gut content metabarcoding has provided important insights into the food web ecology of spiders, the most dominant terrestrial arthropod predators. In small invertebrates, like spiders, gut content analysis is often performed on whole body DNA extracts of individual predators, from which prey sequences are selectively enriched and sequenced.Since many spider species are generalist predators, large numbers of samples comprising individual spider specimens must be analysed to recover an exhaustive image of a spider species' prey spectrum, which is costly and time‐consuming.Pooled processing of bulk samples of multiple specimens has been suggested to reduce the necessary workload and cost while still recovering a representative estimate of the prey diversity. However, it is still unclear if pooling approaches lead to bias in recovering the prey spectrum and if the results are comparable with data from individually processed spiders.Here, we test the effects of metabarcoding pooled spider gut content on the recovered taxonomic diversity and composition of prey. Using a newly adapted primer pair, which efficiently enriches COI barcode sequences of diverse arthropod prey groups while suppressing spider amplification, we test if pooling leads to reduced taxonomic diversity or skewed estimates of prey composition.Our results show that pooling and individual processing recover highly correlated taxonomic diversity and composition of prey. The only exception are very rare prey items which were less well recovered by pooling. Our results support pooling as a cost‐effective and time‐efficient approach to recover the diet of generalist predators for population‐level studies of spider trophic interactions. [ABSTRACT FROM AUTHOR]

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.

Abstract Venom is a remarkable innovation found across the animal kingdom, yet the evolutionary origins of venom systems in various groups, including spiders, remain enigmatic. Here, we investigated the organogenesis of the venom apparatus in the common house spider, Parasteatoda tepidariorum. The venom apparatus consists of a pair of secretory glands, each connected to an opening at the fang tip by a duct that runs through the chelicerae. We performed bulk RNA-seq to identify venom gland-specific markers and assayed their expression using RNA in situ hybridisation experiments on whole-mount time-series. These revealed that the gland primordium emerges during embryonic stage 13 at the chelicera tip, progresses proximally by the end of embryonic development and extends into the prosoma post-eclosion. The initiation of expression of an important toxin component in late postembryos marks the activation of venom-secreting cells. Our selected markers also exhibited distinct expression patterns in adult venom glands: sage and the toxin marker were expressed in the secretory epithelium, forkhead and sum-1 in the surrounding muscle layer, while Distal-less was predominantly expressed at the gland extremities. Our study provides the first comprehensive analysis of venom gland morphogenesis in spiders, offering key insights into their evolution and development.

The ideal free distribution (IFD) theory predicts that individuals are free to move among habitat patches and distribute among them “ideally,” in order to maximize individual evolutionary fitness. Size and quality of habitat patches then should directly impact the number of individuals occupying them, and connectivity of habitat patches likely plays a role if dispersal is limited. However, habitat patches can be distributed so that movement no longer can be considered free, for example, when patches are isolated. Challenges stemming from patch delimitation and detection rate of occupants further complicate efforts attempting to resolve such patterns. Here, we utilize as habitat patches the orb webs of four different populations belonging to three golden orb weaver spider species, Nephila pilipes (Fabricius, 1793), Nephilingis livida (Vinson, 1863), and Trichonephila clavipes (Linnaeus, 1767), and the obligate spider kleptoparasites (Argyrodinae, Theridiidae) that are associated with their webs. We examine how the IFD predicts the abundance of kleptoparasites under different patterns of patch size and distribution. We found that larger host webs, that is, habitat patches that contain more resources, are occupied by a higher number of kleptoparasitic spiders, regardless of their degree of isolation. Although the free movement prediction is often violated in natural systems, we find no evidence for habitat patch connectivity affecting the abundance of kleptoparasites, indicating that their dispersal ability facilitates the location and colonization of habitat patches regardless of their isolation. Therefore, our results support the interaction between argyrodine kleptoparasitic spiders and the webs of golden orb weavers to be a suitable natural system for studying the IFD. [ABSTRACT FROM AUTHOR]

Anti‐cancer peptides (ACPs) represent a promising potential for cancer treatment, although their mechanisms need to be further elucidated to improve their application in cancer therapy. Lycosin‐I, a linear amphipathic peptide isolated from the venom of Lycosa singorensis, shows significant anticancer potential. Herein, it is found that Lycosin‐I, which can self‐assemble into a nanosphere structure, has a multimodal mechanism of action involving lipid binding for the selective and effective treatment of leukemia. Mechanistically, Lycosin‐I selectively binds to the K562 cell membrane, likely due to its preferential interaction with negatively charged phosphatidylserine, and rapidly triggers membrane lysis, particularly at high concentrations. In addition, Lycosin‐I induces apoptosis, cell cycle arrest in the G1 phase and ferroptosis in K562 cells by suppressing the PI3K‐AKT‐mTOR signaling pathway and activating cell autophagy at low concentrations. Furthermore, intraperitoneal injection of Lycosin‐I inhibits tumor growth of K562 cells in a nude mouse xenograft model without causing side effects. Collectively, the multimodal effect of Lycosin‐I can provide new insights into the mechanism of ACPs, and Lycosin‐I, which is characterized by high potency and specificity, can be a promising lead for the development of anti‐leukemia drugs. [ABSTRACT FROM AUTHOR]