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Agricultural intensification has a strong impact on arthropod diversity, yet predators such as spiders provide key ecosystem services through natural pest regulation. Understanding how local and landscape factors shape spider assemblages throughout the season is essential for designing effective agro-ecological infrastructures that can sustain their services in crop systems. We investigated ground-dwelling spider communities in Belgian winter cereal fields and their margins. Pitfall traps were used across seasons to assess the effects of habitat (field vs. margin), surrounding crop cover, and seasonal dynamics on spider richness, activity-density, and community structure. Results show that spider activity-densities were consistently higher in margins than in fields, whereas species richness showed no significant differences between these habitats. Significant seasonal variations were detected on both spider richness and abundance. The landscape effect of the annual crop cover was context dependent, showing seasonal and species-specific patterns and even positive associations in autumn. Seasonal shifts also reflected life stage and sex-specific phenologies. This study reveals that spider communities in Belgian cereal systems are shaped by interacting local, landscape, and seasonal factors. Margins mainly act as refuges that bolster spider numbers rather than species pools, while the influence of the surrounding landscape depends on the season and the species identity. These findings highlight the need to incorporate temporal and biological context when designing margins and other agro-ecological infrastructures to support natural pest regulation providers such as spiders.

The comparison of chromosome-level genomes allows biologists to investigate new axes of organismal evolution. Spiders comprise a significant proportion of known arachnid diversity, with many complex morphologies and unique natural histories, yet comparative genomics in spiders has been limited due to the number of available genomes. We present a de novo chromosomal reference genome of a mature male tarantula, Aphonopelma marxi, and comparatively examine spider genome evolution across the order Araneae. Using PacBio HiFi and Hi-C sequencing, the final 6.5 Gb assembly consists of 17 autosomes, 1 X chromosome, and 127 unplaced scaffolds, with an N50 of 370 Mb and Arachnida (odb10; 2,934 genes) BUSCO of 96.7%. By comparing 20 additional spider genomes from 15 families, we find mygalomorphs (trapdoor spiders and their kin) generally possess more repetitive genomes with similar composition compared to their much more diverse sister lineage, the araneomorphs. We report mygalomorphs recover a lower number of completed BUSCOs than araneomorph spiders, a finding not correlated with sequencing coverage, as mygalomorphs have a portion of missing or derived BUSCOs in the current arachnid dataset. Across the Araneoidea (orb-weaving spiders and their kin), there is a correlation between decreasing genome size and repeat content, suggesting repetitive elements are being lost or removed. Importantly, visualization of macrosynteny across available genomes highlights structural rearrangements and allows identification of previously unreported sex chromosomes. This new, high-quality mygalomorph genome will provide new avenues of exploration for arachnid evolutionary biology.

Sex identification at early stages of development is of great interest for studies in evolutionary biology in many animals. Knowing the sex ratio, even more in offspring, allows testing hypotheses related to the cause of sex ratio biases in populations and species. Spiders born with a defined sex, mostly have an X1X20 sex chromosome system, but it is not possible to determine their sex phenotypically until the adult or near-adult stage. The wolf spider Allocosa marindia inhabits the sandy coast of Southern South America and shows sex role reversal. Laboratory and field studies suggest a strong bias in the sex ratio in favour of females in this species. Here, we analysed the 2C nuclear DNA content by flow cytometry in females and males of A. marindia to determine whether the difference between the sexes is enough to identify the sex of the individuals. The average 2C DNA content for females was 4.96 ± 0.036 pg and for males 4.72 ± 0.020 pg. Then, we tested the usefulness of the technique to sex A. marindia frozen spiderlings, in order to be able to decouple the collection time from the processing time. We analysed 59 spiderlings from four known females. Although we found greater variability in frozen samples, the difference in DNA content was enough to determine the sex of 54 frozen spiderlings (43 females and 11 males). Our results show a promising technique for sexing hatchlings of diplodiploid arthropods. In future studies, we will seek to sex spiderlings from a larger number of mothers to understand the causes of female bias in this species. La identificación del sexo en las primeras etapas del desarrollo es de gran interés para estudios de biología evolutiva en muchos animales. Conocer la proporción de sexos, especialmente en la descendencia, permite probar hipótesis relacionadas con la causa de los sesgos en la proporción de sexos en poblaciones y especies. Las arañas nacen con un sexo definido, en su mayoría tienen un sistema de cromosomas sexuales X1X20, pero no es posible determinar su sexo fenotípicamente hasta la etapa adulta o casi adulta. La araña lobo Allocosa marindia habita arenales costeros del sur de Sudamérica y muestra inversión de roles sexuales. Estudios de laboratorio y de campo sugieren un fuerte sesgo en la proporción de sexos a favor de las hembras en esta especie. Aquí, analizamos el contenido nuclear 2C de ADN por citometría de flujo en hembras y machos de A. marindia para determinar si la diferencia entre los sexos es suficiente para identificar el sexo de los individuos. El contenido de ADN 2C promedio para las hembras fue de 4,96 ± 0,036 pg y para los machos de 4,72 ± 0,020 pg. A continuación, probamos la utilidad de la técnica para determinar el sexo de crías congeladas de A. marindia, con el fin de separar el tiempo de recolección del tiempo de procesamiento. Analizamos 59 crías de cuatro hembras conocidas. Si bien encontramos mayor variabilidad en las muestras congeladas, la diferencia en el contenido de ADN fue suficiente para determinar el sexo de 54 crías congeladas (43 hembras y 11 machos). Nuestros resultados muestran una técnica prometedora para determinar el sexo de crías de artrópodos diplodiploides. En estudios futuros, buscaremos determinar el sexo de crías de un mayor número de madres para comprender las causas del sesgo hacia las hembras en esta especie.

In tropical forests, there is a high diversity of parasites that use arthropods as resource, particularly arachnids. One of the most frequent groups of spiders' parasites in tropical forests are fungi of the genus Gibellula, for which a considerable knowledge gap remains in these environments. In this study, we present the description of a new species that infects spiders of the species Iguarima censoria (Anyphaenidae) in the Brazilian Atlantic Forest, Gibellula mineira sp. nov. We also described the prevalence of the new fungal species in the host spider population and evaluated whether the host size influences their probability of parasitism. Morphological and molecular analyses revealed that G. mineira represents a distinct species forming a clade with 100% support of bootstrap and showing a close phylogenetic relationship with Gibellula aurea. The characteristics that distinguish it from other species of the genus include light brown hyphae, white and slightly larger conidiophores, and thinner phialides. We observed a high prevalence of parasitism in this interaction, reaching 25% of the observed I. censoria population. Furthermore, we noted that the cadavers of parasitized spiders are exclusively attached to the underside of leaves, following the typical pattern observed for Gibellula species. Parasitism is more frequent in smaller I. censoria individuals, which is probably associated with thinner cuticles or higher foraging activity in smaller individuals. We suggested that G. mineira is an important natural enemy of I. censoria, directly influencing the population dynamics of this spider and expanding our knowledge of the ecology and biodiversity of araneopathogenic fungi.

Spider webs are increasingly recognised as passive environmental collectors; however, fungi remain amongst the least explored biological components associated with spider silk, particularly when examined using culture-based and taxonomically resolved approaches. In this study, we present a proof-of-concept investigation of culturable fungal diversity associated with two-dimensional, debris-decorated orb webs, constructed by the orb-weaving spider Cyclosa mulmeinensis in rice agroecosystems in Thailand. Using a standardised field-to-laboratory isolation workflow combined with genus-appropriate multilocus phylogenetic analyses, decorated orb webs were sampled as individual units from rice agroecosystems in Thailand and fungi were isolated via dilution plating on potato dextrose agar supplemented with chloramphenicol. A total of 112 fungal isolates were recovered, grouped into 45 colony morphotypes and resolved into 23 taxa across six genera: Alternaria, Aspergillus, Cladosporium, Fusarium, Penicillium and Talaromyces. Taxonomic placement was inferred primarily from multilocus phylogenetic analyses, with morphological characteristics used as supporting evidence. Notably, several isolates formed well-supported lineages within Cladosporium and Talaromyces that could not be assigned to any described species, indicating the presence of potentially undescribed taxa. These findings demonstrate that spider webs can serve as a low-impact, non-destructive substrate for accessing viable fungal diversity in agricultural ecosystems. This approach enables reproducible culture-based recovery of taxonomically informative fungal lineages and highlights the potential of spider web sampling as a complementary tool for biodiversity assessment and environmental monitoring.

Venoms are complex chemical arsenals that have evolved across various animal lineages for predation, defence, and other ecological functions. In predatory species, venom composition is often shaped by diet, potentially leading to unique toxin profiles. Spiders are the most diverse group of terrestrial venomous predators, yet the venoms of most species, including highly specialised stenophagous species with narrow trophic niches, remain poorly understood. In this study, we investigated the venom of Ammoxenus amphalodes, a spider that preys exclusively on termites, to explore its molecular composition and functional adaptations. Using a proteotranscriptomic approach, we identified 116 putative toxin sequences. Half of these were cysteine-rich peptides with distinct structural motifs, most of which diverge from known spider toxins containing an inhibitor-cystine-knot (ICK) motif. The venom proteome is dominated by two ammoxotoxin families, which together account for more than half of all transcripts, supporting the hypothesis that spiders with specialised diets have lower toxin diversity. We also identified a low proportion of larger venom proteins, including cholinesterases, phospholipases, immune proteins, carbonic anhydrases, and EF-hand proteins, which may serve housekeeping functions or play auxiliary roles in prey incapacitation. Pilot bioassays with selected lab-produced peptides revealed one peptide, U-AXTX(9)-Aa15, a member of the waprin family, which induced stronger paralysis in termites than in flies. However, the other tested peptides showed similar or higher paralysis in flies, challenging assumptions of venom specialization in A. amphalodes. These findings provide new insights into the evolution of venom in dietary specialists and broaden the search for novel bioactive compounds with potential biotechnological applications.

Spiders are renowned for their ecological versatility and silk-based innovations in materials science, yet marine environments remain virtually uncolonized by this predominantly terrestrial lineage. A striking exception is the obligate intertidal spider genus Desis, whose members have evolved extraordinary physiological and behavioural adaptations to persist in wave-swept, saline habitats that oscillate between land and sea. However, the molecular basis of these adaptations has remained largely unexplored. Here, we present a high-quality, chromosome-scale genome of the intertidal spider Desis jiaxiangi, together with a reference genome of the water spider Argyroneta aquatica, integrated with transcriptomic and proteomic data. This multi-omics framework reveals the genomic architecture underlying adaptation to life at the ocean's edge. We uncover expansions of gene families linked to hormone biosynthesis and DNA repair, alongside signatures of adaptive evolution in genes involved osmoregulation, the rate-limiting step of glycolysis, mitochondrial regulation, epithelial tube morphogenesis and circadian rhythm. Notably, we characterize a novel silk spidroin enriched with a unique GVGAKV motif, which may enhance silk hydrophobicity, and detect the duplication burst of hemocyanin genes likely supporting oxygen transport during submersion. Together, these findings reveal convergent molecular strategies for coping with extreme and fluctuating environments, and demonstrate how genomic innovation enables terrestrial lineages to invade marine-influenced ecosystems. Our study establishes Desis as powerful model for understanding adaptation at terrestrial-marine interface.

Spider-pathogenic fungi serve as critical regulators of spider populations in natural systems, playing irreplaceable roles in maintaining ecological balance and also serving as reservoirs of bioactive compounds. Despite recent taxonomic refinements at the generic level, their broader phylogenetic diversity remains significantly underrepresented compared to entomopathogenic fungi. In this study, we collected several novel spider-pathogenic fungi from various provinces in China and conducted comprehensive taxonomic and phylogenetic analyses. Based on integrated morphological characterization and multigene phylogenetic analyses of five loci (ITS, nrLSU, TEF1, RPB1, and RPB2), eight novel species are described and illustrated: Arachnidicola (1), Gamszarella (1), Gibellula (2), Hevansia (1), and Liangia (1) within Cordycipitaceae; Husseyia (1) within Clavicipitaceae; and Purpureocillium (1) within Ophiocordycipitaceae. Additionally, six new combinations are proposed, one Chinese new record is reported, the type specimen of one known species is revised, and five potential cryptic species are identified. Our phylogenetic analyses provide robust evidence for the taxonomic placement of Chlorocillium and Husseyia within Clavicipitaceae. Molecular clock analysis, utilizing a dataset of five loci from 648 fungal strains, estimated the stem and crown ages of Hypocreales and indicated that spider-pathogenic fungi likely emerged during the mid-Cretaceous and subsequently diversified. Multiple lineages displayed marked trends toward host specialization, suggesting that these fungi developed highly efficient parasitic strategies to exploit constrained ecological niches. This research substantially expands the documented diversity of araneopathogenic fungi, providing a robust phylogenetic framework for elucidating their evolutionary origins and diversification patterns, while offering valuable biological resources for future biotechnological and ecological applications.

Animal coloration is a complex trait useful for studying adaptive evolution. In consequence, a major goal in evolutionary biology is to understand the genetic and developmental basis underlying coloration in animals and thus establish direct links between genetic and phenotype variability. Genomics tools have contributed the identification the specific genes and variants responsible for color variation in nonmodel animals, but the evidence is biased toward some taxa, while groups such as arachnids have been neglected. In this study, we aimed to identify genes that underlie coloration in spiders and generate genomic resources for these organisms. By deep sequencing RNA-seq libraries from yellow, orange, white, and black female morphs of the color polymorphic spider Gasteracantha cancriformis, we assembled a transcriptome for this species and identified genes that were differentially expressed between color morphs. Among these, we detected genes with known roles in pigmentation pathways for carotenoids, melanin, ommochromes, and pteridines, suggesting that both pigmentary and structural coloration are involved in abdominal coloration in spiders. Signatures of positive selection on these genes suggest that abdominal coloration in G. cancriformis plays an adaptive role, although the specific selective pressures remain unknown. However, the fact that we identified more venom gland genes expressed in the most conspicuous morphs we tested (i.e., yellow and orange) suggests that abdominal coloration likely serves a defensive function against predators in these spiders. Overall, our results provide evidence that several pathways that control pigmentation in insects and vertebrates also play a role in arachnids.

Consistent among-individual differences in behaviours, also known as animal personalities, are ubiquitous across the animal kingdom. At the same time, the expression of these behaviours may remain context- and time- dependent. Social spiders lack morphological castes and apparent dominant hierarchies, but show consistent among-individual differences in behaviours such as boldness and aggression. Previous studies have shown that these personality traits are not associated with task participation and that personality repeatability weakens over longer durations. In this study, we tested whether short-term boldness was stable across intrinsic (nutritional state) and extrinsic (disturbance) contexts in the Indian social spider, Stegodyphus sarasinorum. We subjected individuals to feeding or starvation and repeated disturbance or no disturbance treatments, and measured boldness over three consecutive days. We found that neither variation in nutritional state nor disturbance influenced the mean boldness scores or their repeatability. Our results show that boldness is robust to short-term changes in hunger and disturbance. The ecological and social functions of the boldness personality trait remain unresolved in social spiders and further studies are warranted to understand how exactly among-individual variation in boldness influences colony productivity and demographic outcomes.

Anthropogenic activities have intensified soil degradation and disrupted essential ecological processes, underscoring the need for effective ecological restoration strategies. Terminalia argentea, a pioneer species of the Cerrado, has demonstrated potential for recovering degraded areas and facilitating arthropod recolonization. Arthropods are sensitive to environmental changes and are thus recognized as bioindicators. This study aimed to assess the recovery of a degraded area by evaluating insect and spider ecological indices, their interactions, and the plant biomass of T. argentea saplings over a two-year field establishment period. Saplings with greater biomass (e.g., more leaves/branch) supported a higher abundance and richness of tending ants. During the first year after planting, the leaves of T. argentea saplings exhibited higher numbers of chewing insects (e.g., Cerotoma sp.) and their ecological indices (e.g., diversity), spiders (e.g., Oxyopidae) and their species richness, bees (e.g., Trigona spinipes) and their abundance, and tending ants (e.g., Brachymyrmex sp.) and their diversity and richness of species. In contrast, saplings in the second year after planting hosted higher numbers of sap-sucking insects (e.g., Aphis spiraecola), their tending ant Camponotus sp., and their Dolichopodidae predators. Saplings with more sap-sucking insects (e.g., Phenacoccus sp.) also had more tending ants (e.g., Camponotus sp.). However, an increase in tending ants (e.g., Ectatomma sp.) was associated with a reduction in predators (e.g., Photinus sp.) and chewing insects (e.g., Lamprosoma sp.). The presence of spiders (e.g., Araneidae) was correlated with higher numbers of chewing insects (e.g., Cephalocoema sp.), while Mantis religiosa and Polybia sp. were more common on saplings with higher defoliation percentages, and Syrphus sp. was associated with Bemisia sp.. These results indicate that trophic interactions, mediated by both bottom-up and top-down mechanisms, structure the arthropod community on T. argentea, promoting the coexistence of functional groups and enhancing ecological indices. Future studies involving predator exclusion and leaf chemical analyses will be essential to deepen this understanding.

With the rapidly growing demand for flexible energy storage devices in wearable electronics, the development of electrode materials that combine high energy/power density with excellent flexibility has become critical. Inspired by the natural "spiderweb-mucilage" structure, we successfully prepared a lignin-based electrode material via electrospinning, carbonization, and hydrothermal processes. This material achieves efficient dual-mode energy storage by mimicking the synergistic roles of the spider web and mucilage. The material features an rGO-CNFs skeleton with high conductivity (4.02 S·cm-1) and flexibility, serving as a "conductive spider web", while NiCo-LDHs nanosheets are anchored as "mucilage" for rapid Faradaic reactions. The above components are tightly interconnected by stable M-O-C chemical bonds, endowing the composite structure with excellent mechanical robustness. This design yields exceptional performance: a specific capacitance of 1492.6 F·g-1 at 1 A·g-1, vastly surpassing pure CNFs (161.4 F·g-1) and rGO-CNFs (440.6 F·g-1). Such excellent electrochemical performance originates from the synergistic effect of dual-energy storage and the significantly enhanced electrolyte wettability of the electrode, whose contact angle with the electrolyte is reduced from 133.3° to 34.4°. The assembled flexible symmetric supercapacitor achieves an energy density of 82.67 Wh·kg-1 at 800 W·kg-1 and retains 94.5% capacitance after 2000 cycles, demonstrating excellent stability.

Spider mites, particularly Tetranychus urticae Koch and T. turkestani Ugarov and Nikolskii (Acari: Tetranychidae), are major agricultural pests, and their increasing resistance to chemical acaricides underscores the need for alternative control strategies. This study explored the biocontrol potential of Trichoderma spp. against these mites. Specifically, we evaluated (1) the efficacy of spore suspensions from five isolates of four Trichoderma species (Trichoderma afroharzianum, T. guizhouense, T. harzianum and T. virens) and their combinations on different biological stages of T. urticae, (2) the efficacy of T. afroharzianum spore suspension on different populations of T. urticae (green and red forms) and T. turkestani in both Petri dish and pot experiments. Results showed that Trichoderma spore suspensions were ineffective against T. urticae eggs, with mortality rates ≤ 2.8% at 7 days post-application (dpa), which did not differ significantly from the control. However, the fungi caused significant mortality of 50-65% in the mobile stages of the mites (larvae, nymphs, and adult females) compared with the control. Based on the initial screening results, a single Trichoderma isolate (T. afroharzianum) was selected for detailed assessment across multiple spider mite populations. Petri dish assays at 7 dpa showed that T. afroharzianum was more effective against T. turkestani (up to 60%) and the green form of T. urticae (53%) than against the red form of T. urticae (35%). Pot experiments confirmed these results, showing that T. afroharzianum reduced egg and mobile stage populations by 36-39% in T. turkestani and T. urticae (green form and laboratory culture populations), whereas reductions in the red form of T. urticae were not statistically significant. These findings suggest that T. afroharzianum has potential as a biological control agent; however, its efficacy varies among spider mite populations, highlighting the need to integrate it with other biological or chemical strategies.

Acid gases pose a severe threat to human health, rendering their rapid visual detection imperative, particularly in unfamiliar environments. Compared with other detection methods, fluorescent polymeric micro-nano luminescence fibers offer a promising approach for the visual and rapid monitoring of acid gases. Herein, a type of poly(lactic acid) lumnescent micro-nano fibers with a spider-web structure (PLA-ZNF) were successfully fabricated through electrospinning. Scanning electron microscopy (SEM) images revealed that the spider-web structure constituted more than 80% of the overall structure, endowing the PLA-ZNF with a significantly enhanced specific surface area. The fluorescence spectra indicated that the spider-web structure resulted in a significantly higher fluorescence intensity of PLA-ZNF than that of conventional polylactic acid micro-nano luminescent fibers (PLA-NF). Moreover, PLA-ZNF demonstrated excellent detection ability for acid gases, with response times of only 5 s for hydrochloric acid and nitric acid, and 7 s for formic acid and acetic acid vapors. The combination of good recyclability, flexibility, and mechanical properties of PLA-ZNF as a promising material for the wide application in visual and rapid detection of acid gases.

Brown spider envenomation (loxoscelism) represents a significant public health concern in South America, yet most studies focus on a few medically recognized species. Here, we provide the first molecular and functional characterization of the venom gland extract from Loxosceles aff. variegata (LafvVGE), a brown spider collected in synanthropic habitats in Ituiutaba, Minas Gerais, Brazil. SDS-PAGE and immunoblot analyses revealed prominent protein bands consistent with phospholipase D (PLD) toxins, the main agents of loxoscelism symptoms. ELISA assays demonstrated that LafvVGE is effectively recognized by Brazilian therapeutic antivenoms, indicating immunological cross-reactivity. Enzymatic assays confirmed sphingomyelinase and collagenase/gelatinase activities comparable to those of Loxosceles gaucho (a species of acknowledged medical relevance), although LafvVGE from female individuals showed higher activities than male derived pools under our experimental conditions. Neutralization assays showed complete inhibition of sphingomyelinase activity but only partial inhibition of gelatinase activity by the anti-loxoscelic antivenom, highlighting differential susceptibility of venom components to antivenom-mediated neutralization under in vitro conditions. Molecular analysis of venom gland transcripts identified eight distinct PLD isoforms (LafvPLD1-8), all containing conserved catalytic and metal-binding residues characteristic of class II Loxosceles PLDs. Structural modeling revealed isoform-specific variations in the aromatic cage motif and electrostatic surface, suggesting potential effects on membrane interactions and substrate specificity. Collectively, these findings place L. aff. variegata within the biochemical and structural spectrum of medically relevant Loxosceles species, expanding comparative knowledge of PLD diversity and function. While clinical relevance remains to be established in vivo, this study underscores the value of integrating biochemical, immunological, and structural analyses to identify emerging venom phenotypes with potential implications for surveillance and antivenom coverage.

Spiders are major predatory natural enemies in agricultural and forest ecosystems and play an important role in pest control. The vitellogenin receptor (VgR) mediates the endocytosis of vitellogenin (Vg) into developing oocytes, providing essential nutrients for embryogenesis and playing a critical role in insect reproductive processes. In this study, A VgR gene was cloned from adult female Pardosa astrigera (L. Koch) and designated as PastVgR1. The open reading frame of PastVgR1 is 5,337 bp in length and encodes a protein of 1,779 amino acids, with a predicted molecular weight of 197.8 kDa. Sequence analysis revealed that the PastVgR1 protein possesses an N-terminal signal peptide consisting of the first 17 amino acid residues and contains conserved domains characteristic of the LDLR superfamily. RT-qPCR analysis showed that PastVgR1 expression was highly specific to the ovaries, with the highest levels in virgin females. RNA interference (RNAi)-mediated silencing of PastVgR1 significantly prolonged the pre-oviposition period, caused ovarian atrophy and oocyte dispersion, reduced both the number of eggs laid per female and the hatching rate, and delayed ovarian development. In summary, PastVgR1 represents a promising molecular target for enhancing the mass rearing of predatory spiders used in biological pest management. Optimizing the large-scale production of these natural enemies could lower the cost of biological control and ultimately support the development of sustainable, green agriculture.

The insecticidal molecules of spiders persistently evolve to ensure rapid paralysis of their prey, and the best molecules are transmitted to their progeny. Here, we cloned two insecticidal peptides, Bs2 and Bs3, from the venom glands of the theraphosid Brachypelma smithi. Bs2 and Bs3 are 90.2% identical, but they exhibit interesting structural differences at their C-termini, including a connecting disulfide bond (residues Cys15-Cys36 for Bs2 and Cys15-Cys30 for Bs3). The genomic origin of Bs2 and Bs3 may be a cause for gene duplication events. Moreover, Bs2 differs in two residues from Tal1 (95.1% identical), an insecticidal peptide, from the tarantula Tliltocatl albopilosus. Likewise, Bs3 is similar to Asp3a from Aphonopelma sp., a peptide that targets mammalian Cav (voltage-dependent Ca2 + channel), but it has not been tested in insects. Bs2 and Bs3 were cloned and recombinantly expressed in bacterial cells, and their paralytic effects were tested on three species of insects. The insecticidal peptide rBs2 with the connecting loop Cys15-Cys36 was significantly more insecticidal than that of rBs3 when affecting Galleria mellonella larvae (Lepidoptera). Yet, the insecticidal peptide rBs3 with the connecting loop Cys15-Cys30 was significantly more insecticidal than that of rBs2 when affecting Acheta domesticus nymph crickets (Orthoptera), and Gromphadorhina portentosa cockroaches (Blattodea). rBs2 and rBs3 structural models show a low-structured C-terminal in rBs3, which correlates with a more flexible amino acid sequence of such C-terminal from residues Tyr30 to Leu42. Since insecticidal spider peptides are constantly evolving for prey capture, they are valuable ion channel antagonists for understanding insect cell receptors, and they are also promising leads for insect control.

Spider mites (Oligonychus trichardti) are emerging as a major constraint to Urochloa forage productivity in East Africa; however, knowledge of genotypic variation and tolerance remains limited. Herein, 55 Urochloa genotypes were evaluated under field-infested and non-infested conditions across two seasons using an alpha-lattice design. Agronomic and physiological traits, including plant height (PH), tiller number (TN), the Normalized Difference Vegetation Index (NDVI), total dry weight (TDW), and mite damage indices (visual severity index (VSI) and stress tolerance index (STI)) were assessed. Infestation reduced biomass by 22.4% on average, with reductions of up to 45% in susceptible genotypes. Significant genotypic variation was detected for PH, TN, TDW, and VSI. Heritability estimates under mite infestation were moderate to high for all traits except TDW, suggesting that direct selection of these traits could be effective in breeding programs aimed at improving mite resistance. VSI showed a strong negative correlation with NDVI (r = -0.63), supporting its value as a phenotyping indicator of spider mite response. Additive main effects and multiplicative interaction (AMMI) analysis revealed significant genotype × environment interactions for TDW. The AMMI biplot identified Xaraes, ILRI_13369, and ILRI_14787 as high-yielding and stable genotypes, while the AMMI Stability Value (ASV) and the Weighted Average of Absolute Scores from the Best Linear Unbiased Prediction (WAASB) identified CIAT_16122, CIAT_664, ILRI_14801, ILRI_14787, and ILRI_13266 as the most stable and broadly adapted across environments. STI further highlighted ILRI_13751 (2.71) and ILRI_13531 (2.58) as highly tolerant under stress. Overall, the study reveals substantial exploitable genetic diversity and identifies stable, high-yielding, and mite-tolerant genotypes suitable for breeding to improve Urochloa productivity in East Africa.

Based on several small collections, new taxonomic and faunistic data on spiders of the United Arab Emirates (UAE), Saudi Arabia, Kuwait, and Lebanon are presented. Six species are described as new to science: Dorceus saif Szűts & Zamani, sp. nov. (♂; Saudi Arabia), Loureedia melanconi Szűts & Zamani, sp. nov. (♂; Saudi Arabia) (both Eresidae), Leptopilos hajarensis Zamani & Marusik, sp. nov. (♀; UAE), Synaphosus dulcicola Zamani & Marusik, sp. nov. (♀; UAE) (both Gnaphosidae), Arctosa formosa Zamani & Marusik, sp. nov. (♂♀; UAE) (Lycosidae), and Prodidomus emiratus Zamani & Marusik, sp. nov. (♀; UAE) (Prodidomidae). In addition, the previously unknown male of Trichothyse golan (Levy, 1999) (Gnaphosidae) is illustrated and described. Finally, one new family record, 16 new generic records and 22 new species records are documented, and the previous record of Sahastata infuscata (Kulczyński, 1901) (Filistatidae) from Yemen is rejected.