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• 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 present study documents novel egg parasitoid-host associations between two genera of baeine wasps and a myrmecomorph spider, Myrmaplata plataleoides (O. Pickard-Cambridge) from West Bengal, India. Until now, no egg parasitoids have been reported from any myrmecomorph spiders. Of the two species, Idris bharati Debnath and Rajmohana sp. nov. is described as new, while Odontacolus markadicus Veenakumari is reported for the first time from the eggs of M. plataleoides. The mt COI DNA barcode sequences for these two species are the only sequences of baeine wasp species from India. Additionally, a preliminary phylogenetic tree has been provided for the members of Idris. Some interesting observations on the nesting behaviour and maternal care of M. plataleoides are also provided. [ABSTRACT FROM AUTHOR]

Plesiopelma longisternale is a widespread tarantula in Argentina and its limit is difficult to determine due to their morphological variation among populations. Males are distinguishable by the following character combination: a field of spines on the apical half of the palpal tibia, a very long embolus and a field of spines on the reotrolateral face of cymbium; females are characterized by long spiraled ducts distant from each other. Here, we used mitochondrial DNA (cox1) to reconstruct the first phylogeny of P. longisternale , in combination with morphological data and molecular species delimitation, to assess the taxonomic limits of this species. Our phylogenetic results confirm a close relationship among the populations from central Argentina and a new evolutionary independent lineage identified as a new species, Plesiopelma absconditus , which is here diagnose, described and illustrated. We further analyzed the diagnostic characters of P. longisternale through the examination of the types and specimens from many populations and found that their morphological intraspecific variations largely overlap. Altogether, our results demonstrate that some of the variability of P. longisternale in central Argentina represent polymorphisms of a single species supported by molecular data. In addition, we discovered a new species from this genus distinguishable by molecular and morphological data and highlight the need for multiple lines of evidence to solve the taxonomic problems in species of tarantulas. [ABSTRACT FROM AUTHOR]

The presence and proportions of photopigments, which are responsible for the visual and physiological effects of light, vary between taxonomic groups. This leads to differing wavelength sensitivities ranging from ultraviolet (UV; <400 nm) to infrared (IR; >780 nm) and complicates the balancing of spectra used for outdoor lighting to maximize human visual performance while mitigating light pollution effects on wildlife. I developed a database of spectral response information for terrestrial wildlife to create generalized spectral response curves by taxonomic phylum, class, and order. Existing data on species visual sensitivity were collected from previously published research that used behavioral responses, electroretinograms (ERGs), and reflectance within the eye. Resulting summaries of photopigment peak sensitivities (n=968) and sensitivity curves (n=177) allow for general observations. Overall, longer wavelengths provide the highest possibility for supporting human visual performance at night while reducing intrusive overlap with the vision of other species, because many taxonomic groups are sensitive to light in the blue and into the ultraviolet. Comparison of average response curves at the class level and the spectral power distribution of lamps suggests that spectral tuning might reduce the apparency of the lowest correlated color temperature (CCT) lamps to insects, spiders, and non-human mammals the most, with substantial but smaller reductions for reptiles, birds, and amphibians. Spectral tuning, most simply by reducing CCT, should be considered an additional benefit to be used in concert with other mitigation measures such as dimming, shielding, and part-night lighting. [ABSTRACT FROM AUTHOR]

Loxosceles spider envenomation results in dermonecrosis, principally due to phospholipases D (PLDs) present in the venom. These enzymes have a strongly conserved sequence, 273 ATXXDNPW 280 , in the C-terminal region (SMD-tail) that make contact with β-sheets of the TIM barrel, in which the amino acids Asp277 and Trp280 establish the energetically strongest contacts. The SMD-tail is conserved in PLDs from different species but absent in the non-toxic PLD ancestral glycerophosphodiester phosphodiesterases (GDPDs). This work aims to understand the role of the C-terminal region in the structural stability and/or function of phospholipases D. Through site-directed mutagenesis of the rLiD1 protein (recombinant Loxosceles intermedia dermonecrotic protein 1), we produced two mutants: rLiD1D277A and rLiD1W280A (both with sphingomyelinase activity), in which Asp277 and Trp280 were replaced by alanine. rLiD1D277A showed similar sphingomyelinase activity but at least 2 times more dermonecrotic activity than rLiD1 (wild-type protein). Conversely, while the rLiD1W280A displayed a slight increase in sphingomyelinase activity, its biological activity was similar or lower compared to rLiD1, potentially due to its decreased thermostability and formation of amyloid aggregates. In conclusion, these new findings provide evidence that SMD-tail mutants impact the structure and function of these proteins and point out that residues outside the active site can even increase the function of these enzymes. • Spider PLD's C-terminal mutation, Asp277 to Ala, increases dermonecrosis in vivo. • The Asp277 to Ala mutation does not affect enzymatic activity in vitro. • Spider PLD's C-terminal mutation, Trp280 to Ala, lowers enzyme thermostability. • Trp280 to Ala mutation slightly increases enzyme activity in vitro. • Mutations in PLD's conserved C-terminal amino acids affect its structure and function. [ABSTRACT FROM AUTHOR]

Wind disturbances and consequent salvage logging lead to drastic changes in forest soil conditions, vegetation and microclimate, potentially affecting arthropod communities. In mountain regions, topography is expected to be particularly important to modulate the effect of canopy removal and soil disturbance potentially amplifying the ecological contrast between forest and disturbed areas. Here, we studied the short-term response of ground beetles (Carabidae), spiders (Araneae), and harvestmen (Opiliones) in wind-damaged spruce forests along statistically orthogonal gradients in elevation, slope, and aspect. We addressed three main ecological questions: (i) Does the effect of wind disturbance on diversity depend on topography? (ii) Are there specific taxon-related responses to disturbances?, and (iii) What is the role of dispersal in shaping species assembly dynamics? We generally observed that increasing slope and elevation amplified the differences between undisturbed forest and windfall areas. On the one hand, the diversity of ground beetles and harvestmen seemed to be negatively affected by wind disturbance, causing a loss of specialized forest species with a low rate of colonization of species typical of open habitats. On the other hand, several novel spider species were able to rapidly colonize windfalls and community composition strongly shifted from forest to disturbed areas. Species with long-range dispersal strategies (e.g. flying and ballooning) were those more likely to colonize windfalls. Our findings suggest that disturbance effects on ground-dwelling organisms were modulated by underlying environmental gradients and that short-term response of different taxa was dependent on their dispersal ability. [Display omitted] • Wind disturbance and salvage logging affected forest ground-dwelling arthropods, driving community changes in the short term. • Changes in activity density of ground beetles, spiders and harvestmen after disturbance were mediated by elevation and slope. • Forests at high elevations and on steep slopes were more sensitive to disturbance. • Spiders showed a high species turnover rate with richer communities occurring after disturbance. • Species with long-distance dispersal strategies occurred more frequently in windfalls. [ABSTRACT FROM AUTHOR]

As a consequence of agricultural intensification and habitat fragmentation since the mid-20th century, biological diversity has declined considerably throughout the world, particularly in Europe. We assessed how habitat and landscape-scale heterogeneity, such as variation in fragment size (small vs. large) and landscape configuration (measured as connectivity index), affect plant and arthropod diversity. We focused on arthropods with different feeding behaviour and mobility, spiders (predators, moderate dispersal), true bugs (mainly herbivores and omnivores with moderate dispersal), wild bees (pollinators with good dispersal abilities), and wasps (pollinators, omnivores with good dispersal abilities). We studied 60 dry grassland fragments in the same region (Hungarian Great Plain); 30 fragments were represented by the grassland component of forest-steppe stands, and 30 were situated on burial mounds (kurgans). Forest-steppes are mosaics of dry grasslands with small forests in a matrix of plantation forests. Kurgans are ancient burial mounds with moderately disturbed grasslands surrounded by agricultural fields. The size of fragments ranged between 0.16–6.88 ha (small: 0.16–0.48 ha, large: 0.93–6.88 ha) for forest-steppes and 0.01–0.44 ha (small: 0.01–0.10 ha and large: 0.20–0.44 ha) for kurgans. Fragments also represented an isolation gradient from almost cleared and homogenous landscapes, to landscapes with relatively high compositional heterogeneity. Fragment size, connectivity, and their interaction affected specialist and generalist species abundances of forest-steppes and kurgans. Large fragments had higher species richness of ground-dwelling spiders, and the effect of connectivity was more strongly positive for specialist arthropods and more strongly negative for generalists in large than in small fragments. However, we also found a strong positive impact of connectivity for generalist plants in small kurgans in contrast to larger ones. We conclude that besides the well-known effect of enhancing habitat quality, increasing connectivity between fragments by restoring natural and semi-natural habitat patches would help to maintain grassland biodiversity. [ABSTRACT FROM AUTHOR]

Oil palm (Elaeis guineensis) is a tropical crop that produces palm oil: the most traded vegetable oil worldwide. It is principally grown in Southeast Asia, but West Africa – oil palm's native range – is rapidly becoming a hotspot of cultivation. Oil palm in West Africa is cultivated using both traditional (i.e., by local people) and industrial (i.e., by corporations) approaches. Little is known about the relative ecological impacts of these different oil palm cultivation styles on native rainforest ecosystems. Working in Liberia within the framework of the Sustainable Oil Palm in West Africa (SOPWA) Project, we investigated the impacts of traditional and industrial approaches to oil palm cultivation on spiders—important meso-predators that provide pest control services—inhabiting understory vegetation. We sampled spiders in three systems: (1) rainforest, (2) fallowed farmland with wild-growing oil palms, which local people manage and harvest ('country palm'), and (3) industrial oil palm farms. We assessed differences in the abundance of all spiders, adults only, and juveniles only; spider species richness, and spider species-level community composition. Through focussed samples of orb web-building spiders, we also assessed differences in spider web-building (the average web area, total web area, standard deviation of web area) and prey capture (the average captured prey, total captured prey, standard deviation of captured prey) across systems. We found that rainforest had more species in total and on average than country palm and industrial oil palm, and that country palm had fewer spider individuals than rainforest and industrial oil palm. All systems supported distinct spider communities. Our focussed studies on orb web-building spiders indicated that the average web area, total web area, and standard deviation of web area were all higher in industrial oil palm than forest and country palm, which led to higher average and total prey capture. Our findings indicate that conversion of rainforest to country palm and industrial oil palm in Liberia has negative effects on spider biodiversity, with clear "winning" and "losing" species, and levels of spider-associated ecosystem functioning. Our findings also show that industrial oil palm farms can support relatively abundant and speciose spider communities, which may provide important pest control services that could boost oil palm productivity. Future work is needed to identify effective management strategies to conserve spiders and associated pest control services in West African country palm and industrial oil palm systems. • Ecological impacts of oil palm cultivation in West Africa are poorly known. • We compared spiders in forest and oil palm managed traditionally and industrially. • Rainforest had the most species, and systems differed in species-level composition. • Industrial oil palm contained species with larger webs, enhancing prey capture. • Spiders—and their pest control services—should be conserved in oil palm systems. [ABSTRACT FROM AUTHOR]

Predator-prey interactions are the interspecific relationships of greatest interest in ecology. Spiders are among the most diverse and ubiquitous terrestrial predators on the planet. Their large dietary breadth is often linked with the development of specific predatory behaviors and morphological adaptations. However, studies on the predatory behavior of spiders have mostly focused on specialist species, leaving behind the ethological variability occurring in generalist species that allow them to respond to the different prey types. For three species of generalist wandering spiders, we searched images of predation events on the Internet to determine the most common prey. Subsequently, the focal predator species were then used in behavioral experiments. Using high-speed videos, handling patterns for different prey types (spider and cricket) were analyzed. Our results show a notable difference in handling patterns between prey types. We found that the spider prey was often rotated around the axis allowing the predator to bite in the ventral region of the prey and thus avoid a counterattack. Contrary, crickets were arbitrarily rotated. Our work may be an indication that these three species of generalist spiders have a preference for manipulating prey differently with a preference to rotate spiders, allowing them to exploit prey with various defensive mechanisms. • Bite Location: we observed a preference for ventral biting spider prey in the field, online and in the laboratory. • Prey Manipulation: Spider prey is rapidly but non-stereotypically manipulated for a ventral bite, crickets for a dorsal bite. • Unique Behavioral Units: Phoneutria depilata and Trechalea sp. have exclusive behavioral units. • Maximal Velocity and Spider Size: maximum velocity in all three wandering spider species depends on spider size. [ABSTRACT FROM AUTHOR]

Most spiders rely on specialized capture threads to subdue prey. Cribellate spiders use capture threads, whose adhesion is based on thousands of nanofibers instead of specialized glue. The nanofibers adhere due to van der Waals and hygroscopic forces, but the adhesion is strengthened by an interaction with the cuticular hydrocarbons (CHCs) covering almost all insects. The interaction between CHCs and cribellate threads becomes visible through migration of the CHCs into the thread even far beyond the point of contact. In this study, we were able to show that the migrated CHCs not only influence adhesion but also change the mechanical characteristics of the thread. While adhesion, extensibility and total energy decreased in threads treated with CHCs from different insects, we observed an increasing force required to break threads. Such mechanical changes could be beneficial for the spider: Upon the first impact of the insect in the web, it is important to absorb all the energy without breaking. Afterwards, a reduction in extensibility could cause the insect to stay closer to the web and thus become additionally entangled in neighboring threads. An increased tensile force would additionally ensure that for insects already in the web, it is even harder to free themselves. Taken together, all these changes make it unlikely that cribellate spiders reuse their capture threads, if not reacting rapidly and removing the prey insect before the CHCs can spread across the thread. Cribellate spiders use capture threads that, unlike other spiders, consist of nanofibers and do not rely glue. Instead, prey adheres mainly because their surface compounds, so-called cuticular hydrocarbons (CHCs), interact with the thread, this way generating strong adhesion forces. Previous studies on biomechanics and adhesion of cribellate threads only dealt with artificial surfaces, neglecting any interaction with surface compounds. This study examines the dramatical mechanical changes of a cribellate thread after interaction with prey CHCs, showing modifications of the thread's extensibility, tensile force and total energy. Our results highlight the importance of studying mechanical properties of silk not only in an artificial context, but also in real life. [Display omitted] [ABSTRACT FROM AUTHOR]

A new species, Tekellina araucana sp. n., is described from Chile and Argentina. Detailed morphological data from the spinnerets and male palp of T. araucana sp. n. and Tekellina sadamotoi Yoshida & Ogata, 2016 is provided. A new diagnostic character of Tekellina Levi, 1957 , a row of bottle-like modified setae between the anal tubercle and the spinnerets was found. The absence of aggregate and cylindrical gland spigots may be a further diagnostic character for the genus. New molecular sequence data of T. araucana sp. n., Tekellina archboldi Levi, 1957 (generotype) and Nescina kohi Lin, Ballarin & Li, 2016 , is provided and analyzed together with legacy genetic and transcriptomic data from a wide sampling of species representing all areaneoid families. Both molecular and morphological data suggest that Tekellina is closely related to Synotaxus Simon, 1895 together with three genera formerly placed in Nesticidae. From those results we broaden the limits of Synotaxidae to include the genera Synotaxus, Hamus Ballarin & Li, 2015 , Nescina Ballarin & Li, 2015 , Gaucelmus Keyserling, 1884, and Tekellina. The morphological data, especially of the male palps, is consistent with that re-limitation. [ABSTRACT FROM AUTHOR]

• Optimization of lycorine extraction from roots of Giant Spider Lily by using RSM. • Ultrasound assisted extraction (UAE) was found superior for lycorine recovery. • Independent variables like SS ratio and extraction time contributed for maximizing the recovery of lycorine. • Extraction yield increased from 2.19 to 5.84 mg/g DW. Crinum x amabile Donn ex Ker Gawl. is an ornamental and medicinally important bulbous plant. It is a vital source of an anticancer alkaloid called lycorine (LY). In the present study, LY extraction was enhanced by using Response Surface Methodology (RSM) with Box-Behnken Design (BBD). Optimal responses were recorded at 95% ethanol concentration, 1:30 g/mL SS ratio and 30 min extraction time with the highest recovery of LY (5.84 mg/g DW) when roots were subjected to ultrasonic assisted extraction (UAE). Among tested extraction methods, highest LY content was noted from UAE (3.74±0.00 mg/g DW), while lowest in Soxhlet extraction (1.68±0.007 mg/g DW). Promising antioxidant activities like DPPH (0.10±0.05 mg AAE/g extract), ABTS (2.44±0.04 mg AAE/g extract), FRAP (3.66±0.08 mg Fe (II)E/g extract), and PMA (3.680±0.12 mg AAE/g extract) were recorded from the extract obtained through UAE. Similarly, remarkable α-amylase activity (54.04±0.04 %) and the highest alkaloid content (1.5±0.01 mg SE/g extract) were recorded from the UAE extracts. This study proved that parameters such as SS ratio and extraction time positively influence the extraction of LY. Roots of C. x amabile could be used as a potent source of an anticancer alkaloid and as an innovative drug to control oxidative stress related disorders. [ABSTRACT FROM AUTHOR]

• In the Westerwald mountain range, mid-western Germany, humid long-term fallows rather than traditional hay meadows harboured the highest spider richness and diversity. • Spider assemblages were structured by on-site management, and additionally by eutrophication, fallow-related parameters, and the proportion of forests in the surrounding landscape. • In traditional landscapes of rather low land-use intensity, enhancing structural heterogeneity, e.g. through fallows, may be of key importance to promote spider diversity. • Long-term grassland fallows should be subsidized under agri-environmental schemes. Agricultural intensification is an important driver of biodiversity decline. Regarding grassland ecosystems, traditionally managed hay meadows, as opposed to highly productive silage grassland, are often of high conservation value. Here, we compare spider assemblages among five grassland management regimes along an intensification gradient, ranging from long-term fallows (not farmed for ≥ 30 years) via traditionally managed hay meadows to high-intensity silage grassland. Humid long-term fallows harboured highest species richness and diversity, and their assemblages differed strongly from other management regimes. There was surprisingly little variation though among different types of hay meadows and silage grassland. We also included environmental parameters and land-cover types in the surroundings of study sites, indicating that spider assemblages were most strongly shaped by fallow-related parameters and the proportion of forests. The high spider diversity on fallows may result from their undisturbed vegetation structure, while management, regardless of frequency, may have detrimental effects. Our results demonstrate the high importance of unmanaged areas even in regions with an overall low land-use intensity, such as grassland ecosystems. We thus recommend the inclusion of temporal grassland fallows (unmanaged for 3-5 years) in agri-environmental schemes to increase landscape heterogeneity and preserve spider diversity. [ABSTRACT FROM AUTHOR]

Soft and stretchable electronics have garnered significant attention in various fields, such as wearable electronics, electronic skins, and soft robotics. However, current wearable electronics made from materials like conductive elastomers, hydrogels, and liquid metals face limitations, including low permeability, poor adhesion, inadequate conductivity, and limited stretchability. These issues hinder their effectiveness in long-term healthcare monitoring and exercise monitoring. To address these challenges, we introduce a novel design of web-droplet-like electronics featuring a semi-liquid metal coating for wearable applications. This innovative design offers high permeability, excellent stretchability, strong adhesion, and good conductivity for the electronic skin. The unique structure, inspired by the architecture of a spider web, significantly enhances air permeability compared to commercial breathable patches. Furthermore, the distribution of polyborosiloxane mimics the adhesive properties of spider web mucus, while the use of semi-liquid metals in this design results in remarkable conductivity (9 × 10 6  S/m) and tensile performance (up to 850% strain). This advanced electronic skin technology enables long-term monitoring of various physiological parameters and supports machine learning recognition functions with unparalleled advantages. This web-droplet structure design strategy holds great promise for commercial applications in medical health monitoring and disease diagnosis., (Copyright © 2024 Science China Press. Published by Elsevier B.V. All rights reserved.)

Loxoscelism is a serious public health problem in Peru, with approximately 2500 accidents reported per year. To envision alternatives to cope with this health problem, the neutralizing humoral immune response against the lethal effects of Peruvian spider Loxosceles laeta venom was evaluated in a mouse model by immunization with a non-toxic multiepitopic protein (rMEPLox). This immunogen contains epitopes from an astacin-like metalloprotease, a hyaluronidase and a sphingomyelinase-D from Loxosceles intermedia and from SMase-I from L. laeta venoms. In vivo protection assays showed that five out of six mice immunized with rMEPLox (after six injections) resisted to 1.4 LD 50 of L. laeta venom, whereas only two animals from a control group survived. The present results indicates that this multiepitopic protein can be a promising candidate for anti-loxoscelic antivenom production and experimental vaccination approaches. [Display omitted] • Loxoscelism is a serious public health problem in Peru, with approximately 2500 accidents reported per year. • A recombinant protein containing epitopes from Loxosceles spp. toxins is recognized by Peruvian L. laeta antivenom. • rMEPLox induces neutralizing antibodies against Peruvian L. laeta venom in mice. • rMEPLox is a good candidate for vaccination or antivenom production approaches. [ABSTRACT FROM AUTHOR]

There is general awareness of artificial selection and its potential implications on the health and welfare of animals. Despite growing popularity and increasing numbers of reptile breeds of atypical colour and pattern variants, only a few studies have investigated the appearance and causes of diseases associated with colour morphs. Ball pythons (Python regius) are among the most frequently bred reptiles and breeders have selected for a multitude of different colour and pattern morphs. Among those colour variants, the spider morph of the ball python is frequently associated with wobble syndrome. The aim of this study was to determine whether a morphological variant can be found and associated with the clinical occurrence of wobble syndrome in spider ball pythons, using computed tomography and magnetic resonance imaging as in-vivo diagnostic methods. Data from five spider and three wild type ball pythons was assessed and evaluated comparatively. We were able to identify distinctive structural differences in inner ear morphology in spider ball pythons, which were highly likely related to wobble syndrome. To our knowledge, this is the first report of these anomalies and provides a basis for further anatomical and genetic studies and discussion of the implications for animal welfare in reptile breeding. [ABSTRACT FROM AUTHOR]

We present the case of a 32-year-old male patient hospitalized during the COVID-19 pandemic because of a Brown spider bite on his lower lip. The Brown spider accident occurred in southern Brazil; at hospital admission, the patient presented on his lip: edema, pustules, necrotic regions, and ulcerations. The patient complained of lower back pain, fever and dyspnea. Laboratory tests showed monocytosis, leukocytosis, neutrophilia, increased D-dimer levels, C-reactive protein, glutamate-pyruvate transaminase, delta bilirubin, creatine phosphokinase, procalcitonin, and fibrinogen. The patient was hospitalized and a multi-professional team carried out the treatment. The medical team diagnosed loxoscelism with moderate changes. The dentist treated the oral cavity. The patient began to develop nausea, vomiting, and desaturation episodes during hospitalization. A computed tomography of the chest was performed, which showed signs of viral infection. The RT-PCR test for COVID-19 was positive. The systemic conditions worsened (renal dysfunction, systemic inflammatory response, pulmonary complications). This condition may have resulted from the association of the two diseases (loxoscelism and COVID-19), leading to the patient's death. This case illustrates the difficulties and risks in treating patients with venomous animal accidents during the pandemic, and the importance of a multi-professional team in treating such cases. [Display omitted] • Describes a local and systemic reaction to a Brown spider bite on the lower lip. • The combined systemic effect of Brown spider venom and SARS-CoV-2 infection. • Special attention in treating patients after Brown spider bites. • Loxoscelism -a condition that increases and exacerbates inflammatory response. [ABSTRACT FROM AUTHOR]

Crop diversification is an increasingly recognized management strategy to support biodiversity and ecosystem services, like pest and disease control, in agricultural systems. However, a significant obstacle to its adoption is the potential trade-off between ecosystem services and optimizing yields. We used a two year, on-farm study in Eastern Germany to test how different spatial arrangements of soy (Glycine max L.) and winter wheat (Triticum aestivum L.) can affect pest abundance, aphid predation, and natural enemy biodiversity as well as yields. We compared conventional sole cropping to three types of spatially diversified cropping systems: relay intercropping, wide strip cropping, and patch cropping. Strip cropping generally supported some of the highest levels of carabid abundance both years and spider abundance in 2022 without any yield penalties. While the relay system failed due to insufficient precipitation, strip cropping produced similar or higher yields than sole cropping (124 % and 96 % of the sole wheat yield and 96 % and 109 % of sole soy yield in 2022 and 2023, respectively). Strip cropping supported significantly more carabid beetles compared to sole cropped soy both years and sole cropped wheat in 2022. We found significantly different carabid community composition between wheat strips and patches and the corresponding soy strips and patches. There were no differences in aphid abundance between systems. Nevertheless, we found 51 % and 36 % higher aphid predation rates in wheat strips compared to wheat patches in 2022 and 2023. Our results provide initial insights into the potential of strip cropping to support both natural enemies and yields while also being an approachable diversification strategy for farmers. • Wide strip cropping increased carabid abundance and aphid predation, with no yield penalties. • Row relay intercropping may not be viable in our sandy continental region due to drought. • Aphid abundance was unaffected by cropping treatment but aphid predation was higher in strips than in patches. [ABSTRACT FROM AUTHOR]

Spider-derived peptides with insecticidal, antimicrobial and/or cytolytic activities, also known as spider venom antimicrobial peptides (AMPs), can be found in the venoms of RTA-clade spiders. They show translational potential as therapeutic leads. A set of 52 AMPs has been described in the Chinese wolf spider (Lycosa shansia), and many have been shown to exhibit antibacterial effects. Here we explored the potential to enhance their antimicrobial activity using bioengineering. We generated a panel of artificial derivatives of an A-family peptide and screened their activity against selected microbial pathogens, vertebrate cells and insects. In several cases, we increased the antimicrobial activity of the derivatives while retaining the low cytotoxicity of the parental molecule. Furthermore, we injected the peptides into adult Drosophila suzukii and found no evidence of insecticidal effects, confirming the low levels of toxicity. Our data therefore suggest that spider venom linear peptides naturally defend the venom gland against microbial colonization and can be modified into more potent antimicrobial agents that could help to battle infectious diseases in the future. [Display omitted] • Bioengineering of three derivatives of a natural Lycosa shansia short linear venom peptide. • Enhanced charge and/or hydrophobicity in the engineered peptides. • Bioengineered modifications translate into increased antimicrobial activity. • Retained low toxicity to insects and vertebrate cells. [ABSTRACT FROM AUTHOR]

An important ecosystem service in agriculture is the regulation of pests. However, modern agricultural practices often disrupt natural enemies that provide these services. Adopting Integrated Pest Management (IPM) can conserve natural enemies that protect crop yield and reduce production costs, but surprisingly few field studies have experimentally demonstrated at production scale that IPM improves biological control. We evaluated an integrated system that combined a specialty crop (watermelon as the target crop) surrounded by a field crop (corn) on commercial-level plots to compare IPM based on pest action thresholds with Conventional Pest Management (CPM) that relied on preventative or "insurance" pesticide applications with insecticide-treated seedings and calendar-scheduled insecticide applications to manage insect pests. Over two years at multiple sites, we measured the abundance of key pests (striped cucumber beetle (SCB) Acalymma vittatum Fabricius in watermelon and western corn rootworm Diabrotica virgifera virgifera LeConte in corn, generalist predators (spiders), and non-pest prey (Collembola), as well as field predation estimated with surrogate prey. In watermelon, the abundance of SCB, spiders, Collembola, and field predation was three times or greater on average in IPM compared to CPM field plots where the pest action threshold was rarely reached regardless of treatment. In the surrounding corn, abundances across trophic levels were similar between plots planted with either neonicotinoid-treated or untreated seeds. This study demonstrates how indiscriminate use of insecticides as a pest management strategy can directly (in watermelon) and indirectly (in the surrounding corn) disrupt the benefit of natural enemies and non-pest prey, and mask regulatory ecosystem services otherwise available in commercial crop production. • Preventative insecticides in watermelon production disrupt biocontrol services. • IPM in watermelon can increase pests, non-pest prey, predators and field predation. • Cucumber beetle pests managed with IPM generally remain below action thresholds. • IPM can provide effective pest management in US Midwest watermelon production. [ABSTRACT FROM AUTHOR]

Whip spiders (Amblypygi Thorell, 1883) are easily distinguished from their spider relatives (Araneae Clerck, 1757) by their raptorial pedipalps, the second pair of appendages, which are covered in spines and used to grasp and impale prey. Among other characters, the number, distribution, and size differences among the pedipalp spines continue to be important for whip spider systematics at different levels in the taxonomic hierarchy. However, traditional meristic and qualitative characters used to describe the pedipalp spines often limit their use for species-level taxonomy, as character states are invariant or overlapping. The present study employs landmark-based morphometrics to map the morphospace comprising the retrolateral surface of the pedipalp patella and its dorsal spines in a group of Neotropical whip spiders of the genus Phrynus Lamarck, 1801, all of which share an inconspicuous spine on the prodorsal surface of the pedipalp tarsus, i.e., "group B" proposed by Quintero (1983). The analysis presented demonstrates that the relative pedipalp patella lengths and the patella spine P3 length to patella width ratios are of similar use for species diagnosis as the commonly employed relative length of leg femur I. Importantly, the analysis reveals that, beyond the traditional approach of qualitatively reporting relative pedipalp patella dorsal spine lengths (e.g., P3 > P5 > P2 > P4 > P6 > P1), the ratios between spine lengths are useful morphometric characters for species-level taxonomy in Phrynus. New morphometric ratios are provided for the species of Phrynus group B and used, together with traditional characters, to describe Phrynus guarionexi sp. nov. from the Dominican Republic. Finally, new morphological data are provided concerning the cerotegument, frontal process and prolateral surface of the pedipalp tibia in the species of group B. [ABSTRACT FROM AUTHOR]

A spider nest shaped multi-scale three-dimensional substrate consisting of reduced graphene oxide (RGO) and nickel foam is fabricated for enzymatic electrodes and biofuel cells. According to the excellent conductivity and large electroactive surface area of this special structure, the enzymatic electrodes show large enzymatic loading density, low electron transfer resistance and high electrocatalytic efficiency. The strong forces in the spider nest shaped structure and the excellent enzymatic embedding method ensure the stability of the glucose oxidase bioanodes and laccase biocathodes. The Michaelis–Menten constant value for the bioanodes to glucose is calculated to be 2.24 mM, which is close to the Michaelis–Menten constant for free glucose oxidase, implying a remarkably high enzymatic activity. Employed the obtained bioelectrodes with great properties, the relative glucose/oxygen biofuel cell has an open-circuit voltage of 0.70 V, with a high output power performance, and a maximum output power of 7.05 ± 0.05 mW cm−2, owe to the high enzyme loading and low electron transfer resistance of the electrode based on the spider nest shaped structure. After 60 days of periodic storage experiments, the performance of the biofuel cell still maintained 84.2%, showing a good long-term stability. A unique spider nest shaped multi-scale three-dimensional substrate with extremely large specific surface area and excellent conductivity is employed to fabricate glucose/oxygen biofuel cells with remarkable electrocatalytic efficiency, great output power density and good stability. [Display omitted] • A unique spider nest shaped multi-scale three-dimensional substrate is fabricated. • The bioelectrodes show high enzymatic loading density and catalytic efficiency. • The glucose oxidase on bioanodes shows great enzymatic activity. • High power output and good stability of the biofuel cell is obtained. [ABSTRACT FROM AUTHOR]

A 22 years old undergraduate student was injured three times by a C. medius spider while wearing pants. Right foot and internal lower leg were bitten in three sites, leading to local pain and oedema, besides a total leg paresthesia as immediate symptoms. A series of photographs of the sites were taken since day 0 until resolution in day 10. Two hours after the accident, the victim received intravenous promethazine. Despite cessation of pain and paresthesia after 24 hours, an intense erythema and itching emerged reaching the maximum in day 4, when the victim returned to hospital and received topic dexamethasone and oral dexchlorpheniramine. The regression was complete in day 10. This accident opened room for discussion of empiric drug choice for immediate and subsequent symptoms of unknown envenomations, as good as a reference for further accidents with this common spider. Biological aspects such as venom composition and spider control of delivered venom amount are also discussed. [Display omitted] • An accident with three consecutive bites of Ctenus medius. • Treatment of nonspecific symptoms of spider bite. • Control of venom injection supporting a more severe envenomation after two bites. [ABSTRACT FROM AUTHOR]

Threat superiority effects describe the reaction time advantage for locating threatening objects in a visual search paradigm, compared to locating visually similar non-threatening objects. They are widely reported for threats of both natural (snakes and spiders) and man-made (guns and knives) origins. Across two experiments, the current study contrasts threat superiority effects for natural and man-made targets. When targets are not depicted held, snakes and spiders tended to exhibit larger threat superiority effects, and were searched for with additional caution, than were guns and knives. When snakes and spiders were depicted held and weapons wielded, systematic differences between the natural and man-made threats disappeared. This means the advantage for threats of natural origin observed when all targets were depicted not held may be attributable to differences in animation – snakes and spiders are alive and may strike at any time if in your vicinity, whereas a weapon can only inflict harm if wielded. From these data there is no evidence that evolved visual sensitivities to the basic shapes of venomous animals support faster detection and response times to these animals than can occur to targets such as guns and knives, whose shapes must be learned. The selection pressures that led to the evolution of such sensitivities (observable even in infancy) may therefore lie in protecting young children and babies from envenomation, before they even have the cognitive capacity to understand the dangers that snakes and spiders pose. [ABSTRACT FROM AUTHOR]

Accidents involving Brown spiders are reported throughout the world. In the venom, the major toxins involved in the deleterious effects are phospholipases D (PLDs). In this work, recombinant mutated phospholipases D from three endemic species medically relevant in South America (Loxosceles intermedia , L. laeta and L. gaucho) were tested as antigens in a vaccination protocol. In such isoforms, key amino acid residues involved in catalysis, magnesium-ion coordination, and binding to substrates were replaced by Alanine (H12A-H47A, E32A-D34A and W230A). These mutations eliminated the phospholipase activity and reduced the generation of skin necrosis and edema to residual levels. Molecular modeling of mutated isoforms indicated that the three-dimensional structures, topologies, and surface charges did not undergo significant changes. Mutated isoforms were recognized by sera against the crude venoms. Vaccination protocols in rabbits using mutated isoforms generated a serum that recognized the native PLDs of crude venoms and neutralized dermonecrosis and edema induced by L. intermedia venom. Vaccination of mice prevented the lethal effects of L. intermedia crude venom. Furthermore, vaccination of rabbits prevented the cutaneous lesion triggered by the three venoms. These results indicate a great potential for mutated recombinant PLDs to be employed as antigens in developing protective vaccines for Loxoscelism. • Mutated Loxosceles recombinant Phospholipases-D are non-toxic proteins with antigenic properties. • Vaccination protocols prevented mouse lethality induced by Loxosceles intermedia venom. • Vaccination protocols prevented signals of cutaneous loxoscelism in rabbits caused by Loxosceles venoms. • Serum of vaccinated animals neutralized cutaneous loxoscelism induced by Loxosceles intermedia venom. • Results evidence these non-toxic Phospholipases-D as potential antigens to develop protective vaccines for Loxoscelism. [ABSTRACT FROM AUTHOR]

In the present study, an effort has been made to elucidate the gut bacterial diversity of twelve species of the family Araneidae under three subfamilies collected from 5 states of India along with their predicted metabolic role in functional metabolism. Further, we also compared the host species phylogeny based on partial cytochrome c oxidase subunit I (COI) sequences with the gut bacteria composition dendrogram to decipher the phylosymbiotic relationships. Analysis revealed the presence of 22 bacterial phyla, 145 families, and 364 genera in the gut, with Proteobacteria, Firmicutes, Actinobacteria, and Deinococcus-Thermus as the highest abundant phyla. Moreover, phylum Bacteriodetes was dominated only in Cyclosa mulmeinensis and Chlamydiae in Neoscona bengalensis. At the genus level, Bacillus , Acinetobacter , Cutibacterium , Pseudomonas , and Staphylococcus were the most dominant genera. Furthermore, the genus Prevotella was observed only in Cyclosa mulmeinensis, and endosymbiont Wolbachia only in Eriovixia laglaizei. The differential abundance analysis (DeSeq2) revealed the 19 significant ASVs represented by the genera like Acinetobacter , Vagoccoccus , Prevotella , Staphylococcus , Curvibacter , Corynebacterium , Paracoccus , Streptococcus , Microbacterium , and Pseudocitrobacter. The inter- and intra-subfamilies comparison based on diversity indices (alpha and beta diversity) revealed that the subfamily Araneinae have high richness and diversity than Argiopinae and Gasteracanthinae. The phylosymbiotic analysis revealed that there is no congruence between the gut bacteria composition dendrogram with their host phylogeny. [ABSTRACT FROM AUTHOR]

Loxoscelism is the most dangerous araneism form in Brazil and antivenom therapy is the recommended treatment. Antivenom is produced by horse immunization with Loxosceles spider venom, which is toxic for the producer animal. Moreover, due to the high amount of venom required for horse hyperimmunization, new strategies for antigens obtention have been proposed. In this sense, our research group has previously produced a non-toxic recombinant multiepitopic protein derived from Loxosceles toxins (rMEPLox). rMEPLox was a successful immunogen, being able to induce the production of neutralizing antibodies, which could be used in the Loxoscelism treatment. However, rMEPLox obtention procedure requires optimization, as its production needs to be scaled up to suit antivenom manufacture. Therefore, an effective protocol development for rMEPlox production would be advantageous. To achieve this objective, we evaluated the influence of different cultivation conditions for rMEPLox optimum expression. The optimum conditions to obtain large amounts of rMEPlox were defined as the use of C43(DE3)pLysS as a host strain, 2xTY medium, 0.6 mM IPTG, biomass pre induction of OD 600nm = 0.4 and incubation at 30 °C for 16 h. Following the optimized protocol, 39.84 mg/L of soluble rMEPLox was obtained and tested as immunogen. The results show that the obtained rMEPLox preserved the previously described immunogenicity, and it was able to generate antibodies that recognize different epitopes of the main Loxosceles venom toxins, which makes it a promising candidate for the antivenom production for loxoscelism treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • 20 spiders harbored novel Wolbachia. • Group A was more common than group B in Wolbachia that infect spiders. • We revealed three recombination events of Wolbachia in spiders for the first time. • Our results suggested the horizontal transmission of Wolbachia in spiders. Wolbachia are maternally inherited endosymbiotic bacteria. These intracellular bacteria are common in arthropods and could manipulate host reproduction in diverse ways, such as feminization, parthenogenesis, male killing and cytoplasmic incompatibility. In spiders, infection by Wolbachia has been found in a total of 99 species belonging to 62 genera and 17 families. Furthermore, recent studies analyzed the phylogeny of Wolbachia in Hylyphantes graminicola , 2 cave spiders and Agelenopsis species using multilocus sequence typing (MLST) approach. However, the diversity of Wolbachia strains determined by MLST in spiders from China is still largely unknown. In this study, we collected 1153 spider individuals from Mangshan in China and screened for Wolbachia in 975 individuals representing 68 spider species belonging to 45 genera of 16 families. We analyzed the phylogenetic relationship between Wolbachia and their host spiders by MLST approach. We found novel infections of Wolbachia in 1 family, 9 genera and 20 species of spiders. We found 13 new Wolbachia strains and suggest that group A is more common than group B in Wolbachia that infect spiders. Our results revealed three recombination events of the concatenated multilocus sequences in Wolbachia that infect spiders. Furthermore, our results demonstrated the phylogenetic incongruence between Wolbachia and spiders, suggesting the horizontal transmission of Wolbachia in spiders. We suggest that recombination and horizontal transmission may play an important role in the diversity and evolution of Wolbachia in spiders. [ABSTRACT FROM AUTHOR]

Several classes of toxins are present in the venom of Brown spiders (Loxosceles genus), some of them are highly expressed and others are less expressed. In this work, we aimed to clone the sequence of a little expressed novel toxin from Loxosceles venom identified as a serine protease inhibitor (serpin), as well as to express and characterize its biochemical and biological properties. It was named LSPILT, derived from L oxosceles s erine p rotease i nhibitor- l ike t oxin. Multiple alignment analysis revealed high identity between LSPILT and other serpin molecules from spiders and crab. LSPILT was produced in baculovirus-infected insect cells, resulting in a 46-kDa protein fused to a His-tag. Immunological assays showed epitopes in LSPILT that resemble native venom toxins of Loxosceles spiders. The inhibitory activity of LSPILT on trypsin was found both by reverse zymography and fluorescent gelatin-degradation assay. Additionally, LSPILT inhibited the complement-dependent lysis of Trypanosoma cruzi epimastigotes, reduced thrombin-dependent clotting and suppressed B16-F10 melanoma cells migration. Results described herein prove the existence of conserved serpin-like toxins in Loxosceles venoms. The availability of a recombinant serpin enabled the determination of its biological and biochemical properties and indicates potential applications in future studies regarding the pathophysiology of the envenoming or for biotechnological purposes. • The serine protease inhibitor (LSPILT) of brown spider venom is a serpin. • LSPILT was cloned and expressed in baculovirus-infected cells. • Epitopes in LSPILT resemble native venom toxins of Loxosceles spiders. • The recombinant serpin is able to inhibit trypsin in vitro. • LSPILT inhibited complement system and suppressed B16-F10 melanoma cells migration. [ABSTRACT FROM AUTHOR]

Macrothelidae is a family of mygalomorph spiders containing the extant genera Macrothele and Vacrothele. China is an important center of diversity for Macrothele with 65 % of the known species occurring there. Previous work on Macrothele was able to uncover several important toxin compounds including Raventoxin which may have applications in biomedicine and agricultural chemistry. Despite the importance of Macrothele spiders, high-quality reference genomes are still lacking, which hinders our understanding and application of the toxin compounds. In this study, we assembled the genome of the Macrothele yani to help fill gaps in our understanding of toxin biology in this lineage of spiders to encourage the future study and applications of these compounds. The final assembled genome was 6.79 Gb in total length, had a contig N50 of 21.44 Mb, and scaffold N50 of 156.16 Mb. Hi-C scaffolding assigned 98.19 % of the genome to 46 pseudo-chromosomes with a BUSCO score of 95.7 % for the core eukaryotic gene set. The assembled genome was found to contain 75.62 % repetitive DNA and a total of 39,687 protein-coding genes were annotated making it the spider genome with highest number of genes. Through integrated analysis of venom gland transcriptomics and venom proteomics, a total of 194 venom toxins were identified, including 38 disulfide-rich peptide neurotoxins, among which 12 were ICK knottin peptides. In summary, we present the first high-quality genome assembly at the chromosomal level for any Macrothelidae spider, filling an important gap in our knowledge of these spiders. Such high-quality genomic data will be invaluable as a reference in resolving Araneae spider phylogenies and in screening different spider species for novel compounds applicable to numerous medical and agricultural applications. • The spider is one of the most diverse predators in the natural world, capable of secreting powerful venom toxins from the venom gland. • Although studies have shown the complexity and diversity of spider venom, the exact venom landscape remains unclear. • Here, we have assembled the first Chinese funnel-web spider genome, also the first near chromosome-level genome of the Mygalomorphae spiders. • By combining an integrated analysis of the venom gland transcriptome and venom proteome, we have obtained a comprehensive spider venom catalog. • The distribution of different components in the venom was elucidated. • These findings and results deepen our understanding of spider toxins and provide an invaluable resource for further research. [ABSTRACT FROM AUTHOR]

• This work reports for the first time the presence of adult black widow spiders in winter in northeastern Patagonia. • Some of them even survived the winter, arriving alive the following spring. • All overwintering specimens inhabited abandoned anthropic materials (urban waste) in peri‑urban areas near the city of Puerto Madryn. Cases of araneism reported in the province of Chubut (Argentina) have tripled in the last two decades, and almost 80 % of them involve Latrodectus mirabilis (Holmberg) (Araneae: Theridiidae). According to descriptions of the life cycle of this species in Argentina, the low temperatures typical of autumn-winter cause the death of all adult spiders, so that no adult specimens of L. mirabilis are observed in winter. Field samplings, observations by the Grupo de Entomología Patagónica (GENTPAT, IPEEC CCT CENPAT CONICET), and citizen reports for more than 15 years suggested a similar cycle in northeastern Patagonia. However, for the last three consecutive years, we have recorded adult females in the field throughout the Patagonian winter. Some of these individuals even survived the winter and were alive the following spring. The purpose of this note is to report the field presence of adult female specimens of L. mirabilis in the outskirts of the city of Puerto Madryn (Chubut, Argentina) during the last three consecutive winters corresponding to the years 2021, 2022 and 2023; and to note that at least two of them survived the winter, arriving alive (and in good condition) the following spring. Given the medical importance of this spider, the publication of this information, the context of the findings, and their ecological implications will help to prevent its spread and reduce the likelihood of accidents. [Display omitted] [ABSTRACT FROM AUTHOR]

A long and small duct can be used to control nanoparticles and macromolecules' distributed. [Display omitted] • Spider's spinning process is elucidated and bio-mimicked. • A new electrospinning method with a long tube is designed. • PVDF Nanofibers are fabricated, and the piezoelectric performance is studied. • Application to wearable sensors is discussed experimentally. Scientists have been fascinated by the spider's spinning process, which enables its silk to be incredibly strong. This paper explores the use of a long needle in the electrospinning process to control the inner structure of a PVDF nanofiber. The results show that a longer needle can significantly enhance the nanofiber's piezoelectric performance. The mechanism behind this enhancement is elucidated using the laminar flow theory. [ABSTRACT FROM AUTHOR]

[Display omitted] • Population of spiders and species richness in Bt cotton were high in August. • Maximum abundance was of Hylyphantes graminicola and Neoscona theisi. • Seven guilds of spiders were recorded with diverse nature of hunting crop's pests. • Topmost symbiotic bacterial genus was Wolbachia in spiders. • In grouping and similarity, noticed 5 microbial sets among 4 groups of spiders. The genetically modified cotton holding Bt proteins, is noxious to bollworms larvae but very little is known about its impact on population of non-target spiders within the field. Studies conducted with the aim to identify spiders along with their abundance, prevalence pattern, preying habit on insect pests in Bt cotton (L280, Cry2Ab4) and commonness of symbiotic bacteria in these spiders. Spiders collections were made via vial tapping/jarring, from May to end of October (2018). In total, 13,342 spiders were recorded during the entire cropping season. Least relative abundance was in May (0.28%), highest in August (30.39%) while ahead decline was observed, reached to 12% in October. The 27 species were verified, least richness was in May (3 species), high in August (19 species), later in the end, reduced to 7 species. High abundance was of Hylyphantes graminicola (68.56%) and Neoscona theisi (19.98%). Existence of H. graminicola and Pardosa astrigera observed during the whole cropping season. Presence of seven guilds among spiders had a diverse nature of hunting insect pests and on number of species existed in the crop, maximum was from direct hunting habit. Composition and community structure of microbiota varied as of spider species. Proteobacteria was the most abundant bacterial phylum and topmost genus was Wolbachia in observed spiders. Five groups of bacteria distinguished across 4 clusters of spiders depending on core community of symbiotic bacterial genera. This effort is an initial step to get knowhow about spiders in Bt cotton, which will facilitate future research studies concerning spiders. [ABSTRACT FROM AUTHOR]

Antivenom is the only effective therapy for treating any envenomation. Despite its obvious public health importance, the laborious process of procuring, distributing and controlling the quality of such immunobiologicals is being neglected. Brazil is fully self-sufficient in the production of antivenoms. Since the 1950s, Loxoscelism, a syndrome with an onset after a spider bite from specimens of the Loxosceles genus occurs, is considered a public health issue. The Brazilian history in developing antivenom therapy, its production hindrances, and other challenges are discussed in this paper, as well as some promising novelties that can improve production and processing of Loxosceles antivenom. Image 1 • Loxosceles spiders lead the spider bites cases in Brazil. • Antivenom is the only effective therapy in envenomation cases. • Brazil is self-sufficient in antivenom production. • Challenges in antivenom production include cost, venom acquisition and refrigeration during distribution. [ABSTRACT FROM AUTHOR]

The Loxosceles genus belongs to the Sicariidae family and it comprises species whose venom can cause accidents with potentially fatal consequences. We have previously shown that SMase D is the enzyme responsible for the main pathological effects of Loxosceles venom. Despite the severity of accidents with Loxosceles , few species are considered to be of medical importance. Little is known about the venom of non-synanthropic species that live in natural environments. To contribute to a better understanding about the venom's toxicity of Loxosceles genus, the aim of this study was to (i) characterize the toxic properties of Loxosceles amazonica from two different localities and a recent described cave species Loxosceles willianilsoni and (ii) compare these venoms with that from Loxosceles laeta, which is among the most toxic ones. We show here that both L. amazonica venoms (from the two studied locations) and L. willianilsoni presented SMase D activity similar to that exhibited by L. laeta venom. Although L. amazonica and L. willianilsoni venoms were able to induce complement dependent human erythrocytes lysis, they were not able to induce cell death of human keratinocytes, as promoted by L. laeta venom, in the concentrations tested. These results indicate that other species of Loxosceles , in addition to those classified as medically important, have toxic potential to cause accidents in humans, despite interspecific variations that denote possible less toxicity. • Loxosceles spider venoms may cause accidents with potentially fatal consequences. • Despite the severity of accidents, few species are considered of medical importance. • Venom from the cave species , L. willianilsoni, induce complement dependent hemolysis. • L. willianilsoni and L. amazonica venoms do not induce keratinocyte death as L. laeta. • Loxosceles venoms present interspecific variations in their toxicity. [ABSTRACT FROM AUTHOR]

Web-building spiders secrete dragline silk fibers to sustain their body and use them as frameworks during web construction. They spin dragline silk fibers at various spinning speed and humidity conditions depending on their natural habitat. Here, we investigated the effect of spinning speed and humidity on the structural and mechanical properties of dragline silk fibers from web-building spider Trichonephila clavata obtained by the forcibly spinning method. We found that the crystal and morphological structures did not rely on the spinning speed and humidity. Furthermore, the mechanical strength and extensibility of the dragline silk fibers were maintained, demonstrating that dragline silk fibers ensure robustness irrespective of the spinning speed and humidity. The results obtained in the present study are helpful not only to understand the biological basis of the silk fiber formation of spiders but also contribute to consider the spinning conditions for the process of creating synthetic silk fibers. [ABSTRACT FROM AUTHOR]

Latica galeanoi , the sole species in a new genus within Gnaphosidae, is described from Uruguay and Argentina based on morphological, molecular and biogeographic data. The genus is sister to the rest of the Herpyllinae subfamily. The delimitation of this new genus is supported by various plesiomorphic and synapomorphic characters, which represents homoplasies that allow the genus to be distinguished from other representatives of the subfamily. Species distribution modeling suggests that the most favourable area for the species is the Pampa province. [ABSTRACT FROM AUTHOR]

Whip spiders (Amblypygi) are a group of terrestrial arachnids that exhibit fascinating and unique behavioral habits. The genus Heterophrynus has a wide distribution in South America and since most of the species are morphologically (gross morphology) highly similar to each other there is a strong need of revision. To this purpose, we studied the spermatophore morphology, reproductive behavior and the detailed structure of the reproductive organs in selected members of the genus and evaluate the usefulness of this information for species discrimination. According to our investigation and data from the literature, the reproductive behavior of the observed species are, in most aspects, remarkably similar. Minor differences exist in specific behavioral patterns. The overall behavior is simpler than that in other whip spider genera since it lacks the numerous phases and behavioral patterns they exhibit. The most reliable difference among the concerned species involves the action of the male to modify the spermatophore head with the chelicera before the female takes up the sperm mass. The general schema of the entire spermatophore is quite similar within the genus Heterophrynus , but differences are apparent between the two proposed groups. For example, the sperm package carrier is either plate-like or curved oblong, and the entire sperm mass has different locations. However, the reproductive organs provide among the most reliable characters for distinct species discrimination, since they are formed by variously shaped lobes. Others are the ventral pedipalp spination groups and the ratio between pedipalp tibia length and carapace width. We thus strongly recommend the inclusion of these aspects and especially a detailed description of the reproductive organs in taxonomic works. In addition, a species from Columbia is described as new to science. [ABSTRACT FROM AUTHOR]

Background: Ovarian hormones have been implicated as a potential source of variability in the effectiveness of exposure therapy for anxiety disorders in women. Additionally, preclinical studies in healthy women indicate that ovarian hormones are related to cognitive modes of emotion regulation, like cognitive restructuring. The purpose of the current study was to determine whether a relationship exists between endogenous ovarian hormones and the outcomes of cognitive restructuring in clinically anxious women.Methods: Ninety women with spider phobia received training in cognitive restructuring or a control task and provided a blood sample for the measurement of serum estradiol and progesterone levels. Behavioral avoidance, using a behavioral approach task with a live spider, and self-reported fear of spiders were measured at baseline and 1-week post-treatment.Results: The results indicated that heightened levels of progesterone, but not estradiol, at the time of cognitive restructuring predicted greater post-treatment reductions in behavioral avoidance, but not self-reported fear, amongst women who received cognitive restructuring but not those in the control group.Limitations: As menstrual cycle phase was not assessed; the present study provides information regarding how the benefits of cognitive therapy are predicted by between-person individual differences in absolute hormone levels, but does not examine the relationship between within-person fluctuations in hormone levels and outcomes.Conclusions: These results suggest the effectiveness of cognitive therapy for anxiety disorders in women may differ depending on endogenous levels of progesterone, and raise the possibility that progesterone could be a useful pharmacological adjunct to cognitive therapy. [ABSTRACT FROM AUTHOR]

• We studied carabid and spider responses to impervious surfaces and patch isolation. • The nestedness component mainly explained the total taxonomic and functional β-diversity. • Impervious surfaces cause functional homogenization and turnover in both groups. • Patch isolation homogenizes and shifts species composition in both groups. • Spider dispersal capacity increases with urbanization density and patch isolation. The conversion of natural lands in urban areas is exponentially increasing worldwide, causing a major decline in biodiversity. Environmental alterations caused by urbanization, such as land conversion and isolation of natural patches, favour tolerant and generalist species, causing both species loss and replacement. In addition, selective pressure is exerted on particular functional traits, driving a functional homogenization or turnover of biotic communities. We sampled ground arthropods within the municipality of Turin (NW-Italy), wherein an isolated and a connected control subplot were repeatedly sampled at 15 stations distributed along a gradient of increasing urbanization. Such a nested sampling design allowed us to investigate the taxonomic and the functional responses of carabids and spiders to both the urbanization level and patch isolation. First, we highlighted the dominant role played by species homogenization (nestedness) in explaining both taxonomic and functional variation in both groups of arthropods. Secondly, we showed that urbanization causes simultaneously functional homogenization and replacement in both carabid and spider assemblages, whereas patch isolation influences carabid species composition and homogenizes and shifts spider taxonomic and functional composition. Lastly, by relating community-weighted means of body length, dispersal capacity and trophic strategy to the urbanization and isolation gradients, we demonstrated that urbanization alters the trophic structure of both taxonomic groups and increases the average dispersal capacity of spiders. On the other hand, patch isolation affected the functional composition of spiders only, reducing the body size and increasing dispersal capacity and the proportion of web-builder species. Our results demonstrate that both urbanization and patch isolation alter species composition by causing functional and taxonomic homogenization. In addition, they exert a strong filtering effect on community functional traits, increasing the proportion of phytophagous species in carabids, and increasing dispersal capacity and web-builders occurrence in spiders, while reducing spider body size. [ABSTRACT FROM AUTHOR]

High levels of sociality in spiders interact with morphological traits that enhance dispersal and dispersal propensity. The social spider Anelosimus eximius occurs in tropical rainforests in South America, including in the north and mid-west Amazon, and we have recently found records of its presence in Atlantic Forest, even though the arid features of Cerrado apparently restrict contact between these two areas. In this study we investigated the population history of A. eximius using a spatiotemporal framework. Focusing on biogeographic history, we used sequences of the mitochondrial gene cytochrome oxidase subunit I (COI), to investigate population structure, diversity and time to the most recent common ancestor of the sampled individuals. We aimed to generate ecological niche models to estimate the distribution of the species from the last interglacial to the present. Our results revealed three major clusters in A. eximius (Trans-Andean, Cis-Andean, and French Guiana–Brazil) sharing common ancestors in the Late Pleistocene, c.a. 360 thousand years ago. The last interglacial period revealed a connection between A. eximius populations in Amazonia and the Atlantic forests, through the area currently occupied by the Cerrado. Dispersal over longer distances could be improved by higher rates of propagule production, growth and proliferation of new colonies. This increased dispersal capacity could be provided by wetter environments that promote prey with greater biomass, thus positively impacting the expansion of larger webs. [ABSTRACT FROM AUTHOR]

Loxosceles spp. (Araneae, Sicariidae), known as brown spiders, are distributed in temperate and tropical regions worldwide. Accidents caused by these spiders are known as loxoscelism and constitute a public health problem, especially in Brazil. The present review describes the taxonomy, distribution, and ecological profile of brown spiders, as well as the molecular and biochemical aspects of Loxosceles venom. Additionally, it presents an overview on L. similis, a species found in the Southeastern region of Brazil. In this region, the number of Loxosceles accidents has been increasing in the past few years , thus calling attention to its raising importance as a medically relevant spider species in Brazil. [ABSTRACT FROM AUTHOR]

Protandry occurs when males mature prior to females in the breeding season. There may be a fitness benefit for males if they are able to copulate and defend virgin and more fecund females. Therefore, fitness benefits can be investigated by studying assortative mating during mate guarding of virgin females before and after female sexual maturation. The asynchrony of female development in the protandrous spider Manogea porracea (Araneidae) provides an opportunity to investigate how female sexual maturity (subadult and adult females) influence size-assortative pairing. We investigated size differences between couples composed of males and subadult females, and of males and adult females. We hypothesized that size-assortative pairing is stronger in couples with adult females. Adult females were larger than subadults, but the size of males paired with females from both groups was similar. We found assortative pairing within all couples involving an adult female. However, this pattern was not observed among couples with subadult females. It is possible that the production of sexual pheromones by adult females after their last molt intensifies male intrasexual competition, promoting positive assortative pairing. We discuss the potential mechanisms affecting male mate choice and mate competition during pairings in M. porracea. [ABSTRACT FROM AUTHOR]

Urbanization alters natural landscapes and creates unique challenges for urban wildlife. Similarly, the Urban Heat Island (UHI) effect can produce significantly elevated temperatures in urban areas, and we have a relatively poor understanding of how this will impact urban biodiversity. In particular, most studies quantify the UHI using broad-scale climate data rather than assessing microclimate temperatures actually experienced by organisms. In addition, studies often fail to address spatial and temporal complexities of the UHI. Here we examine the thermal microclimate and UHI experienced in the web of Western black widow spiders (Latrodectus hesperus) , a medically-important, superabundant urban pest species found in cities across the Western region of North America. We do this using replicate urban and desert populations across an entire year to account for seasonal variation in the UHI, both within and between habitats. Our findings reveal a strong nighttime, but no daytime, UHI effect, with urban spider webs being 2–5 °C warmer than desert webs at night. This UHI effect is most prominent during the spring and least prominent in winter, suggesting that the UHI need not be most pronounced when temperatures are most elevated. Urban web temperatures varied among urban sites in the daytime, whereas desert web temperatures varied among desert sites in the nighttime. Finally, web temperature was significantly positively correlated with a spider's boldness, but showed no relationship with voracity towards prey, web size, or body condition. Understanding the complexities of each organism's thermal challenges, the "functional microclimate", is crucial for predicting the impacts of urbanization and climate change on urban biodiversity and ecosystem functioning. • Urban heat island (UHI) effects are often estimated from broad-scale temperature estimates, and finer scale studies of thermal microclimates experienced by urban biota are necessary. • We find a pronounced nighttime UHI in the webs of Western black widow spiders (Latrodectus hesperus). • We also found spatial complexity (thermal patchiness) for urban spiders during the day and desert spiders at night. • Lastly, we found hotter webs to house bolder spiders, but found no relation between web temperature and web size, body condition, or voracity towards prey. [ABSTRACT FROM AUTHOR]

[Display omitted] • Local biodiversity in plantation forests is not higher than in arable lands. • No gains of biodiversity from massive plantations replacing arable land in landscape. • Ground arthropods benefit from rich local non-crop herb communities. City agencies across multiple continents have invested millions of funds in ambitious afforestation projects in urban and peri-urban areas to enhance the city green infrastructure. One example is the Beijing One Million Mu Plain Afforestation Project, which has established 146,000 ha of plantation forests, mainly on arable lands. This contradicts the national arable land conserving policies and has dramatically changed local habitat types and landscape context. However, the impact of these processes on biodiversity is not well understood. To investigate this impact at local and landscape scales, we explored a space-for-time approach. We selected 12 plantation forests and their nearby arable lands along a gradient of plantation forest cover in the surrounding landscapes. We surveyed ground spiders and carabids and analyzed their responses to local habitat type, landscape context, and their interaction. In the sampled landscapes, plantation forest cover increased (12.0%–35.9%), while arable land cover decreased (58.3%–31.8%). 96.3% of the new plantation forests were established on arable lands. Intensive afforestation on arable lands did not increase local ground arthropod diversity. In fact, ground arthropod abundance and species richness in plantation forests were significantly lower than in arable lands when the surrounding arable land cover was relatively high. With surrounding arable land cover decreasing, ground arthropod abundance and species richness in plantation forests increased but did not exceed those in nearby arable lands. Hence, the overall ground arthropod diversity at landscape scale was not improved. These findings suggest that, from a biodiversity conservation perspective, plantation forests did not surpass peri-urban agricultural lands as a better green infrastructure. However, ground arthropods benefit from rich local non-crop herb communities. Conserving peri-urban agricultural lands and implementing extensive management regimes for agricultural lands and existing plantation forests are more effective tools than ambitious afforestation of agricultural land in peri-urban areas of Beijing and other metropolises. [ABSTRACT FROM AUTHOR]

• High complementarity between spider and vascular plants as ecological indicators in peat bogs. • High complementarity between diversity metrics in the understanding of ecological patterns. • Landscape and local factors as interwoven structuring drivers of community in peat bogs. Despite their specific biodiversity and the ecosystem services they furnish, peat bogs remain poorly understood, especially in terms of their responses to changes at multiple spatial scales. Many subarctic peat systems face acute risks, due to current global change. In this study, using a multi-metric approach, we assessed the relative value of plants and spiders as ecological indicators in contrasted peat bogs of a French archipelago (St. Pierre-et-Miquelon), located in the North Atlantic. In 2021, pitfall trapping and suction sampling collected spiders while phytosociological relevés were used to document vascular plants. A total of 69 species of spiders and 38 species of vascular plants were identified, and both taxonomic (TD) and functional (FD, based on traits related to dispersal, size and ecosystem functioning) diversity were then estimated for three levels of species relative abundance (Hill numbers q = 0, 1 and 2) using the iNEXT 3D package for alpha diversity as well as iNEXT beta3D for beta diversity. As expected, patterns of TD and FD were highly correlated for each Hill number, but also between Hill numbers for spiders, indicating a surprisingly low effect of species abundance on (spider) diversity patterns. On the contrary, differences between sites were more visible for plants species when species coverage was considered (q = 1 and q = 2), for both TD and FD, and for alpha and beta diversity. RLQ and Fourth corner analyses indicated differences based on functional traits between sites which were significantly associated with relationships between dispersal modes and mostly local factors for plant assemblages. Finally, variance partitioning on assemblage composition showed the importance of an interaction between local and landscape factors for both plants and spiders, with a relatively high importance of local factors alone for plants. Our study thus revealed the high complementary of spider vs. plant assemblage-based metrics as indicators of changing local conditions in peat bogs, confirming these both experience rapid change in subarctic climates. [ABSTRACT FROM AUTHOR]

Natural floodplains are complex systems embodying an interwoven network of biodiverse aquatic and terrestrial ecosystems. Many floodplains have been impaired and disconnected from the river, leading to declines in biodiversity. River restorations often affect floodplains, yet monitoring programs rarely investigate effects on floodplain organisms. This study examined a river restoration project, which improved river hydromorpholgy and partly reconnected the adjacent floodplain. We applied a 'control–impact' design to investigate changes in floodplain community composition and diversity four, six, eight, and ten years after the restoration of the Nidda River in central Germany. Investigated taxonomic groups included ground beetles, birds, dragonflies, and spiders. We examined trends of abundance, richness, Shannon diversity, Shannon evenness, and temporal turnover over time post-restoration by comparing restored sites to a non-restored control site. Abundance and diversity increased in bird, dragonfly, and spider communities after the restoration. Effect sizes between restored and unrestored sites were mainly positive, indicating that restoration benefitted the investigated taxonomic groups. However, initially high abundance and diversity numbers of ground beetles declined at the restored sites over time, indicating differing responses across taxonomic groups. Our study accentuates and underlines the necessity for ongoing post-restoration monitoring of both floodplain and aquatic biota. [ABSTRACT FROM AUTHOR]