Interaction between spiders and ticks-ancient arthropod predatory behavior?

Ticks are ectoparasite vectors of pathogens affecting human and animal health worldwide. Rational integration of different control interventions including plant-derived repellents and acaricides, management of natural predators, and vaccines is required for innovative approaches to reduce the risks associated with ticks and tick-borne diseases. How tick populations are naturally controlled is always a question. Tick interactions with other arthropods including predators evolved from ancient times. In this study, Cretaceous (ca. 100 Mya) Burmese amber inclusions were identified as probably related to Compluriscutula vetulum (Acari: Ixodida: Ixodidae) tick larvae and spider silk. As illustrated in this study, ancient interactions between ticks and spiders may support arthropod predatory behavior as a natural control intervention. Rational integrative management of different tick control interventions including natural predators under a One Health perspective will contribute to effectively and sustainably reducing the risks associated with ticks and tick-borne diseases.

A brown recluse spider bite wound: a case report and literature review.

DECLARATION OF INTEREST: The authors have no conflicts of interest.

Pest categorisation of Cenopalpus irani.

The EFSA Panel on Plant Health performed a pest categorisation of Cenopalpus irani (Trombidiformes: Tenuipalpidae), known as the Iranian false spider mite, following the commodity risk assessment of Malus domestica plants from Türkiye, in which C. irani was identified as a pest of possible concern for the territory of the European Union (EU). The pest is only known to be present in Iran and Türkiye and has not been reported from the EU. The mite primarily feeds on Rosaceae plants but is considered polyphagous. Important crops of the EU that are hosts of C. irani include apples (Malus domestica), pears (Pyrus communis) and figs (Ficus carica). Plants for planting and fruits provide potential pathways for entry into the EU. Host availability and climate suitability in southern EU countries would most probably allow this species to successfully establish and spread. This mite is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. Phytosanitary measures are available to reduce the likelihood of entry and spread of this species into the EU. The mite C. irani satisfies the criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest, although there is a key uncertainty over the likelihood and magnitude of impact.

A novel spider venom peptide from the predatory mite Neoseiulus barkeri shows lethal effect on phytophagous pests.

The long-term use of pesticides in the field, and the high fertility and adaptability of phytophagous mites have led to resistance problems; consequently, novel safe and efficient active substances are necessary to broaden the tools of pest mite control. Natural enemies of arthropods typically secrete substances with paralytic or lethal effects on their prey, and those substances are a resource for future biopesticides. In this study, two putative venom peptide genes were identified in a parasitic mite Neoseiulus barkeri transcriptome. Recombinant venom NbSP2 peptide injected into Tetranychus cinnabarinus mites was significantly more lethal than recombinant NBSP1. NbSP2 was also lethal to Spodoptera litura when injected but not when fed to third instar larvae. The interaction proteins of NbSP2 in T. cinnabarinus and S. litura were identified by affinity chromatography. Among these proteins, ATP synthase subunit ß (ATP SSß) was deduced as a potential target. Four binding sites were predicted between NBSP2 and ATP SSß of T. cinnabarinus and S. litura. In conclusion, we identified a venom peptide with activity against T. cinnabarinus and S. litura. This study provides a novel component for development of a new biological pesticide.

The use of therapeutic plasma exchange in systemic loxoscelism induced treatment resistant hemolytic anemia: A case report.

Brown recluse spider bites can lead to severe reactions such as skin necrosis,hemolytic anemia, and multiorgan failure, which can be life-threatening. Therapeutic plasma exchange has been reported to provide clinical benefit for such cases. In thisreport, we present a case of a brown recluse spider bite that was successfully treated with therapeutic plasma exchange and compare it with previous case reports.

Loxosceles amazonica Brown Spider venom: Insights into enzymatic activities, immunorecognition, and novel phospholipase D isoforms.

The Loxosceles genus represents one of the main arachnid genera of medical importance in Brazil. Despite the gravity of Loxosceles-related accidents, just a handful of species are deemed medically important and only a few have undergone comprehensive venom characterization. Loxosceles amazonica is a notable example of a potentially dangerous yet understudied Loxosceles species. While there have been limited reports of accidents involving L. amazonica to date, accidents related to Loxosceles are increasing in the North and Northeast regions of Brazil, where L. amazonica has been reported. In this work, we provide a complementary biochemical and immunological characterization of L. amazonica venom, considering its most relevant enzymatic activities and its immunorecognition and neutralization by current therapeutic antivenoms. Additionally, a cDNA library enriched with phospholipase D (PLD) sequences from L. amazonica venom glands was built and subsequently sequenced. The results showed that L. amazonica venom is well immunorecognised by all the tested antibodies. Its venom also displayed proteolytic, hyaluronidase, and sphingomyelinase activities. These activities were at least partially inhibited by available antivenoms. With cDNA sequencing of PLDs, seven new putative isoforms were identified in the venom of L. amazonica. These results contribute to a better knowledge of the venom content and activities of a synanthropic, yet understudied, Loxosceles species. In vivo assays are essential to confirm the medical relevance of L. amazonica, as well as to assess its true toxic potential and elucidate its related pathophysiology.

Fatal Viscerocutaneous Brown Recluse Envenomation With Orbital Compartment Syndrome.

Loxosceles is an arachnid genus comprising several species in the United States, popularly known as brown recluse spiders. The venom is cytotoxic, complex, and has a mixture of many proteins, some of which function as proteases. Envenomation can cause necrotic skin lesions that may become extensive and take many months to heal. Even more rarely, venom may cause systemic effects, leading to widespread hemolysis, coagulopathy, and death. These symptoms typically occur rapidly within 24-48 hours following the bite. We describe a rare case of a 44-year-old male with fatal systemic loxoscelism with orbital compartment syndrome requiring emergent lateral canthotomy and cantholysis.

Management of skin necrosis and wound dehiscence following brown recluse spider bite in the course of breast reconstruction: A case report.

Background: Breast reconstruction following mastectomy is a critical component of breast cancer treatment, aimed at improving patient quality of life. However, the management is fraught with potential complications, including skin necrosis and wound dehiscence, which can significantly impact clinical outcomes. Case Presentation: We report a unique case of a patient, 5 years post-breast reconstruction following mastectomy and radiation therapy, who developed severe skin necrosis and wound dehiscence due to a brown recluse spider bite on the reconstructed breast. The complication necessitated the debridement of skin, removal of the implant, and further reconstruction with a latissimus flap. Discussion: The case underscores the unusual etiology of spider bite-induced necrosis in breast reconstruction and highlights the challenges and strategic considerations in managing such complications. Upon presentation, the patient's affected breast area showed signs of extensive necrosis and wound dehiscence, directly attributed to the cytotoxic effects of the brown recluse spider's venom. The venom's pathophysiology involves a complex cascade, leading to local and systemic effects. The local effects, marked by dermonecrosis, com- promised skin integrity in this instance. Systemic effects, not observed in this patient but potentially severe, can include hemolysis, coagulopathy, and acute renal failure, highlighting the seriousness of brown recluse spider bites. Conclusion: In conclusion, this case illustrates the complexities of managing breast reconstruction post-mastectomy complications, particularly those caused by external factors such as brown recluse spider bites. It highlights the need for meticulous attention to unusual etiologies of necrosis and dehiscence, demonstrating the importance of adaptable surgical strategies and a thorough understanding of venom pathophysiology in ensuring successful patient outcomes.

Otaciliakhezu sp. nov., a new troglobitic spider (Araneae, Phrurolithidae) from Guangxi, China.

Background: Only two Otacilia Thorell, 1897 species with troglobitic characteristics have been recorded from Laos and no records of troglobitic Otacilia species from China. New information: A new troglobitic species is reported from Guangxi, China: Otaciliakhezu Lin & Li, sp. nov. (♂♀). Photos and morphological descriptions of the new species are presented; the type specimens of the new species are deposited in the Institute of Zoology, Chinese Academy of Sciences (IZCAS), Beijing.

Spider and Wasp Acylpolyamines: Venom Components and Versatile Pharmacological Leads, Probes, and Insecticidal Agents.

Polyamines (PAs) are polycationic biogenic amines ubiquitously present in all life forms and are involved in molecular signaling and interaction, determining cell fate (e.g., cell proliferation, dif-ferentiation, and apoptosis). The intricate balance in the PAs' levels in the tissues will determine whether beneficial or detrimental effects will affect homeostasis. It's crucial to note that endoge-nous polyamines, like spermine and spermidine, play a pivotal role in our understanding of neu-rological disorders as they interact with membrane receptors and ion channels, modulating neuro-transmission. In spiders and wasps, monoamines (histamine, dopamine, serotonin, tryptamine) and polyamines (spermine, spermidine, acyl polyamines) comprise, with peptides and other sub-stances, the low molecular weight fraction of the venom. Acylpolyamines are venom components exclusively from spiders and a species of solitary wasp, which cause inhibition chiefly of iono-tropic glutamate receptors (AMPA, NMDA, and KA iGluRs) and nicotinic acetylcholine receptors (nAChRs). The first venom acylpolyamines ever discovered (argiopines, Joro and Nephila toxins, and philanthotoxins) have provided templates for the design and synthesis of numerous analogs. Thus far, analogs with high potency exert their effect at nanomolar concentrations, with high se-lectivity toward their ionotropic and ligand receptors. These potent and selective acylpolyamine analogs can serve biomedical purposes and pest control management. The structural modification of acylpolyamine with photolabile and fluorescent groups converted these venom toxins into use-ful molecular probes to discriminate iGluRs and nAchRs in cell populations. In various cases, the linear polyamines, like spermine and spermidine, constituting venom acyl polyamine backbones, have served as cargoes to deliver active molecules via a polyamine uptake system on diseased cells for targeted therapy. In this review, we examined examples of biogenic amines that play an essential role in neural homeostasis and cell signaling, contributing to human health and disease outcomes, which can be present in the venom of arachnids and hymenopterans. With an empha-sis on the spider and wasp venom acylpolyamines, we focused on the origin, structure, derivatiza-tion, and biomedical and biotechnological application of these pharmacologically attractive, chemically modular venom components.

Identification and Evolutionary Analysis of the Widely Distributed CAP Superfamily in Spider Venom.

Venom plays a crucial role in the defense and predation of venomous animals. Spiders (Araneae) are among the most successful predators and have a fascinating venom composition. Their venom mainly contains disulfide-rich peptides and large proteins. Here, we analyzed spider venom protein families, utilizing transcriptomic and genomic data, and highlighted their similarities and differences. We show that spiders have specific combinations of toxins for better predation and defense, typically comprising a core toxin expressed alongside several auxiliary toxins. Among them, the CAP superfamily is widely distributed and highly expressed in web-building Araneoidea spiders. Our analysis of evolutionary relationships revealed four subfamilies (subA-subD) of the CAP superfamily that differ in structure and potential functions. CAP proteins are composed of a conserved CAP domain and diverse C-terminal domains. CAP subC shares similar domains with the snake ion channel regulator svCRISP proteins, while CAP subD possesses a sequence similar to that of insect venom allergen 5 (Ag5). Furthermore, we show that gene duplication and selective expression lead to increased expression of CAP subD, making it a core member of the CAP superfamily. This study sheds light on the functional diversity of CAP subfamilies and their evolutionary history, which has important implications for fully understanding the composition of spider venom proteins and the core toxin components of web-building spiders.

Review of the genus Karschia Walter, 1889 from Xizang, China (Solifugae, Karschiidae).

The species of the genus Karschia Walter, 1889, collected from Xizang, China, were reviewed. A total of six species were recognized using morphological and molecular data, Karschia (Karschia) tibetana Hirst, 1907 is redescribed based on newly collected males and females, and five new species, Karschia (Karschia) dingyesp. nov., Karschia (Karschia) lhasasp. nov., Karschia (Karschia) zhuisp. nov., Karschia (Karschia) shigatsesp. nov., and Karschia (Karschia) namlingsp. nov., are described.

The protamines of the noble false widow spider Steatoda nobilis provide an example of liquid-liquid phase separation chromatin transitions during spermiogenesis.

While there is extensive information about sperm nuclear basic proteins (SNBP) in vertebrates, there is very little information about Arthropoda by comparison. This paper aims to contribute to filling this gap by analyzing these proteins in the sperm of the noble false widow spider Steatoda nobilis (Order Araneae, Family Theridiidae). To this end, we have developed a protein extraction method that allows the extraction of cysteine-containing protamines suitable for the preparation and analysis of SNBPs from samples where the amount of starting tissue material is limited. We carried out top-down mass spectrometry sequencing and molecular phylogenetic analyses to characterize the protamines of S. nobilis and other spiders. We also used electron microscopy to analyze the chromatin organization of the sperm, and we found it to exhibit liquid-liquid phase spinodal decomposition during the late stages of spermiogenesis. These studies further our knowledge of the distribution of SNBPs within the animal kingdom and provide additional support for a proposed evolutionary origin of many protamines from a histone H1 (H5) replication-independent precursor.

Diversity and Functionality of Bacteria Associated with Different Tissues of Spider Heteropoda venatoria Revealed through Integration of High-Throughput Sequencing and Culturomics Approaches.

Spiders host a diverse range of bacteria in their guts and other tissues, which have been found to play a significant role in their fitness. This study aimed to investigate the community diversity and functional characteristics of spider-associated bacteria in four tissues of Heteropoda venatoria using HTS of the 16S rRNA gene and culturomics technologies, as well as the functional verification of the isolated strains. The results of HTS showed that the spider-associated bacteria in different tissues belonged to 34 phyla, 72 classes, 170 orders, 277 families, and 458 genera. Bacillus was found to be the most abundant bacteria in the venom gland, silk gland, and ovary, while Stenotrophomonas, Acinetobacter, and Sphingomonas were dominant in the gut microbiota. Based on the amplicon sequencing results, 21 distinct cultivation conditions were developed using culturomics to isolate bacteria from the ovary, gut, venom gland, and silk gland. A total of 119 bacterial strains, representing 4 phyla and 25 genera, with Bacillus and Serratia as the dominant genera, were isolated. Five strains exhibited high efficiency in degrading pesticides in the in vitro experiments. Out of the 119 isolates, 28 exhibited antibacterial activity against at least one of the tested bacterial strains, including the pathogenic bacteria Staphylococcus aureus, Acinetobacter baumanii, and Enterococcus faecalis. The study also identified three strains, GL312, PL211, and PL316, which exhibited significant cytotoxicity against MGC-803. The crude extract from the fermentation broth of strain PL316 was found to effectively induce apoptosis in MGC-803 cells. Overall, this study offers a comprehensive understanding of the bacterial community structure associated with H. venatoria. It also provides valuable insights into discovering novel antitumor natural products for gastric cancer and xenobiotic-degrading bacteria of spiders.

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

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

An atlas of spider development at single-cell resolution provides new insights into arthropod embryogenesis.

Spiders are a diverse order of chelicerates that diverged from other arthropods over 500 million years ago. Research on spider embryogenesis, particularly studies using the common house spider Parasteatoda tepidariorum, has made important contributions to understanding the evolution of animal development, including axis formation, segmentation, and patterning. However, we lack knowledge about the cells that build spider embryos, their gene expression profiles and fate. Single-cell transcriptomic analyses have been revolutionary in describing these complex landscapes of cellular genetics in a range of animals. Therefore, we carried out single-cell RNA sequencing of P. tepidariorum embryos at stages 7, 8 and 9, which encompass the establishment and patterning of the body plan, and initial differentiation of many tissues and organs. We identified 20 cell clusters, from 18.5 k cells, which were marked by many developmental toolkit genes, as well as a plethora of genes not previously investigated. We found differences in the cell cycle transcriptional signatures, suggestive of different proliferation dynamics, which related to distinctions between endodermal and some mesodermal clusters, compared with ectodermal clusters. We identified many Hox genes as markers of cell clusters, and Hox gene ohnologs were often present in different clusters. This provided additional evidence of sub- and/or neo-functionalisation of these important developmental genes after the whole genome duplication in an arachnopulmonate ancestor (spiders, scorpions, and related orders). We also examined the spatial expression of marker genes for each cluster to generate a comprehensive cell atlas of these embryonic stages. This revealed new insights into the cellular basis and genetic regulation of head patterning, hematopoiesis, limb development, gut development, and posterior segmentation. This atlas will serve as a platform for future analysis of spider cell specification and fate, and studying the evolution of these processes among animals at cellular resolution.

Eye-specific detection and a multi-eye integration model of biological motion perception.

'Biological motion' refers to the distinctive kinematics observed in many living organisms, where visually perceivable points on the animal move at fixed distances from each other. Across the animal kingdom, many species have developed specialized visual circuitry to recognize such biological motion and to discriminate it from other patterns. Recently, this ability has been observed in the distributed visual system of jumping spiders. These eight-eyed animals use six eyes to perceive motion, while the remaining two (the principal anterior medial eyes) are shifted across the visual scene to further inspect detected objects. When presented with a biologically moving stimulus and a random one, jumping spiders turn to face the latter, clearly demonstrating the ability to discriminate between them. However, it remains unclear whether the principal eyes are necessary for this behavior, whether all secondary eyes can perform this discrimination, or whether a single eye-pair is specialized for this task. Here, we systematically tested the ability of jumping spiders to discriminate between biological and random visual stimuli by testing each eye-pair alone. Spiders were able to discriminate stimuli only when the anterior lateral eyes were unblocked, and performed at chance levels in other configurations. Interestingly, spiders showed a preference for biological motion over random stimuli - unlike in past work. We therefore propose a new model describing how specialization of the anterior lateral eyes for detecting biological motion contributes to multi-eye integration in this system. This integration generates more complex behavior through the combination of simple, single-eye responses. We posit that this in-built modularity may be a solution to the limited resources of these invertebrates' brains, constituting a novel approach to visual processing.

Note on hydrostatic skeletons: muscles operating within a pressurized environment.

Muscles and muscle fibers are volume-constant constructs that deform when contracted and develop internal pressures. However, muscles embedded in hydrostatic skeletons are also exposed to external pressures generated by their activity. For two examples, the pressure generation in spiders and in annelids, we used simplified biomechanical models to demonstrate that high intracellular pressures diminishing the resulting tensile stress of the muscle fibers are avoided in the hydrostatic skeleton. The findings are relevant for a better understanding of the design and functionality of biological hydrostatic skeletons.

Visualization strategies to aid interpretation of high-dimensional genotoxicity data.

This article describes a range of high-dimensional data visualization strategies that we have explored for their ability to complement machine learning algorithm predictions derived from MultiFlow® assay results. For this exercise, we focused on seven biomarker responses resulting from the exposure of TK6 cells to each of 126 diverse chemicals over a range of concentrations. Obviously, challenges associated with visualizing seven biomarker responses were further complicated whenever there was a desire to represent the entire 126 chemical data set as opposed to results from a single chemical. Scatter plots, spider plots, parallel coordinate plots, hierarchical clustering, principal component analysis, toxicological prioritization index, multidimensional scaling, t-distributed stochastic neighbor embedding, and uniform manifold approximation and projection are each considered in turn. Our report provides a comparative analysis of these techniques. In an era where multiplexed assays and machine learning algorithms are becoming the norm, stakeholders should find some of these visualization strategies useful for efficiently and effectively interpreting their high-dimensional data.