Behavior Of Spiders Research Articles

Differential Effects of Ephemeral and Stable Predator Chemical Cues on Spider Antipredator Behaviour

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

Riding on ants: A new report of this interesting behavior in Attacobius spiders (Araneae: Corinnidae)

Riding on ants: A new report of this interesting behavior in Attacobius spiders (Araneae: Corinnidae)

A parallel social spider algorithm based on population mining

The social spider algorithm is a meta-heuristic algorithm inspired by the foraging behavior of biological social spiders, and is initially used to solve optimization problems with continuous functions. There exist many challenges when dealing with discrete combinatorial optimization problems. Therefore, a novel parallel social spider algorithm based on population mining is proposed. Its starting point is to mine dynamic heuristic information from the population of social spiders that cause vibrations to guide the spider’s next walk. It proposes the concept of vibration candidate sets and enhances the behavior of artificial spiders. Furthermore, it is implemented in parallel on the graphics processing unit. According to our investigation, it is the first parallel social spider algorithm. The classical traveling salesman problem is solved as an example. By solving 30 small-scale and medium-scale problems and comparing with other algorithms, it shows that its solution quality is significantly better. By solving 17 large-scale problems, compared with the parallel ant colony system and parallel iterative hill climbing algorithm on the GPU, it is found that both the solution quality and performance are also significantly better. Codes are available at https://github.com/BuptCIAGroup/P-SSA.

Investigating the Influence of Anthropogenic Activities on Behavioral Changes of an Orb Web Spider (Neoscona vigilans).

Orb web spiders are common and highly diversified animals found in almost all habitats. They have remarkable plasticity against biotic and abiotic factors, making them excellent indicators of environmental health. The web creation behavior of spiders is influenced by disturbances in the environment. The aim of this research was to observe the alteration in the web-building behavior of Neoscona vigilans caused by human activities, specifically traffic disturbances. Spider webs were located and photographed at nighttime along the roadside, and their web characteristics were calculated. Spiders were captured from webs for their body measurements. Spider fourth leg length, carapace width, and body length had a significant association with web size and diameter, CTL, capture area, and mesh size. The quantity of trapped prey, the height of the plant, and the foliage radius increased with the distance from the road. Conversely, anchor points and web elevation from the ground dropped. The highest and lowest proportions of anomalies (modifications/defects) were recorded as holes (52.7%) in 105 webs (100%) and supernumerary (0.7%) in 55 webs (52.4%), respectively. Road disturbance had a negative influence on the spider's behavior as the webs formed in close proximity to the road had a higher frequency of anomalies, with a gradual decrease distantly. We can gain further insight into how different environmental changes, disruptions, and pollutants lead to this imperfection in the otherwise flawless perfect structure of spider webs.

An Efficient Modified Black Widow Optimized Node Localization in Wireless Sensor Network

Wireless Sensor Network (WSN) is an encouraging technology in various applications like atmosphere monitoring, vehicular systems, and targeting devices. Localization in WSN is performed to identify the current position or coordinates of sensor nodes. The crucial task of localization is to find coordinates without manual configuration and expensive hardware like GPS. This work proposes a new localization algorithm using Modified Black Widow Optimization (MBWO). The proposed method involves an optimal selection of anchor nodes to reduce localization errors. Black Widow Optimization (BWO) is a naturally inspired optimization algorithm encouraged by the unique coupling behaviour of black widow spiders. The performance of black widow optimization is improved by levy flight distribution to escape from local minima. Experimental results show that the proposed MBWO-optimized localization achieves a higher localized node count with minimized localized error compared to other optimization algorithms.

Rapid prey manipulation and bite location preferences in three species of wandering spiders

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.

RETRACTION: Non‐conceptive sexual behavior in spiders: A form of play associated with body condition, personality type, and male intrasexual selection

Retraction: Pruitt, J. N., Burghardt, G. M., & Riechert, S. E. (2011). Non‐conceptive sexual behavior in spiders: A form of play associated with body condition, personality type, and male intrasexual selection. Ethology, 118(1), 33–40. https://doi.org/10.1111/j.1439‐0310.2011.01980.xThe above article, published online on October 23, 2011 in Wiley Online Library (wileyonlinelibrary.com) has been retracted by agreement between the Journal's Editor‐in‐Chief, Wolfgang Goymann, and Wiley‐VCH GmbH. The retraction has been agreed upon following concerns raised about the validity of the quantitative data reported. J.N. Pruitt, the corresponding author, did not respond following repeated requests to provide the primary data. During the investigation, coauthors S.E. Riechert and G.M. Burghardt requested retraction because they would have no way to validate the article's conclusions without those data. The coauthors have lost confidence in the conclusions of the article, as have the editors and Wiley, hence our decision to retract. Corresponding author J.N. Pruitt was informed of the decision but has remained unresponsive.

A Pareto-optimality based black widow spider algorithm for energy efficient flexible job shop scheduling problem considering new job insertion

The utilization of flexible job shops is on the rise, driven by the decreasing life cycle of consumer products. In dynamic flexible job shops, the occurrence of disruptive events like machine breakdown, tool wear, and new job arrivals is common, emphasizing the critical need for efficient scheduling to achieve productivity and cost-effectiveness. Additionally with the growing concerns about energy consumption and global warming, the imperative to contemplate workshops with lower energy usage is becoming increasingly significant. Therefore, in this study a multi-objective dynamic flexible job shop scheduling problem (MODFJSP) with insertion of new jobs for optimization objectives: makespan, total energy consumption and schedule instability is addressed. A novel multi-objective black widow spider algorithm (MOBWSA), inspired by the mating behavior of black widow spiders, is proposed. The MOBWSA ensures an optimal balance between minimizing makespan and energy consumption through its superior evolutionary processes of procreation, mutation and cannibalism. Furthermore, a strategic on/off strategy is implemented to enhance energy efficiency. The disruptions in schedule at rescheduling stage are addressed through the proposed sigmoidal weighted instability function. To handle the multi-objective nature of the problem this work incorporates Pareto-optimality approach in combination with novel hybrid crowding distance metric. The optimization is further aided by exploitation of search space through an ensemble of local search operators. Testing and evaluation of the MOBWSA with 30 benchmark problems is conducted, and its performance for multiple metrics is compared with recently published state-of-the-art algorithms. The results establish the effectiveness and efficiency of the proposed algorithm.

Summary of caesium evaporation and deposition during SPIDER first campaign

SPIDER (Source for the Production of Ions of Deuterium Extracted from a Radio frequency plasma) is currently in a major shutdown period dedicated to the upgrade of several components in order to enhance its performances and guarantee their agreement with the ITER requirements. During this phase, an in-depth inspection of the beam source components is fundamental to understand SPIDER behaviour during the previous experimental campaigns, and in particular caesium evaporation inside the source by means of Cs ovens. Caesium evaporation and its deposition on the plasma grid (PG) is fundamental to minimize the work function of PG surface causing an increased generation of negative ions and a reduction of the electron density in front of the PG, which means less co-extracted electrons. This work presents the analysis of the caesium ovens performances and of their status after removal. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) analyses were carried out on samples of plasma source walls, and the experimental data was compared to the results obtained from other investigations: numerical models for the caesium evaporation and deposition, chemical surface analyses (performed in strategical locations of the source walls and extraction grid), and Laser Absorption Spectroscopy (LAS) measurements. The non-uniformity of Cs distribution has been taken into account since it has repercussions on negative ion extraction efficiency and uniformity.

Quantitative liquid storage by billiards‐like droplet collision on surfaces with patterned wettability

AbstractThere has been significant interest in researching droplet transport behavior on composite wetting surfaces. However, current research is primarily focused on modifying individual droplets and lacks an in‐depth investigation into high‐precision droplet storage. This study introduces a “billiard ball” droplet transport and storage platform (TSP) with differentiated areas. Within this platform, the volume of droplets stored in the area reaches a consistent threshold through droplet “scrambling,” inspired by the water‐gathering behavior of spiders. The TSP involves connecting two regions of different sizes using a three‐dimensional stepped wedge angle structure. However, this connection is not seamless, leaving a 2‐mm gap between the regions. This gap is intentionally designed to enable continuous droplet transfer while preventing any static migration. Through systematic experimental and simulation analysis, we investigated the influence of superhydrophilic pattern structures and parameters on quantitative droplet storage. We established a functional relationship between the pattern area and the stored volume, and analyzed the intrinsic mechanism of droplet collision separation. This enabled us to achieve on‐demand quantitative droplet storage and autonomize the storage process. The “billiard ball” droplet transport–storage platform proposed in this study holds promising applications in the fields of biomedical and organic chemistry.

A Multi-Objective Approach for Optimal Sizing and Placement of Distributed Generators and Distribution Static Compensators in a Distribution Network Using the Black Widow Optimization Algorithm

This paper presents a new optimization technique for the locations and sizes of Distributed Generators (DGs) and distribution static compensators (DSTATCOMs) in a radial system of a distribution network based on a multi-objective approach. It uses black widow optimization to improve voltage profile and power loss reduction. The black widow optimization simulates the mating behaviour of black widow spiders. The optimum size and placement of DGs and DSTATCOMs are deemed to be decision variables that are defined by using black widow optimization. The proposed technique is implemented in selected IEEE bus systems to evaluate its performance. The simulation results indicate reduced power losses and voltage profile enhancement as sizes and locations of integrated DGs and DSTATCOMs are adjusted based on optimization. The number of DGs and DSTATCOMs required to achieve the objectives is reduced. Furthermore, the results of the black widow algorithm are compared to existing techniques in the literature.

Infection‐related sexual conflict in mating behaviors of wolf spiders

AbstractResistance to mating by females has been hypothesized as a tactic to assess potential mates and avoid undesirable ones. Previous studies show infection with the pathogenic bacteria, Pseudomonas aeruginosa, triggers a costly immune response and negatively impacts fitness in the wolf spider Schizocosa ocreata (Hentz 1844). Studies also show that infection can be transmitted during copulation, suggesting that there are potential fitness costs associated with mating with an infected individual. We examined impacts of infection on mating interactions of male and female S. ocreata. As studies show infection can be detected through chemical cues, we tested whether males or females avoid mating with infected individuals when given the opportunity. We paired infected and uninfected (control) males and females and recorded their behavior. We found that mating outcome was independent of infection for males and females. While higher male courtship rates and more frequent female receptivity displays were associated with successful mating, we saw no direct effect of infection status on mating outcome. However, among spider pairs that did not mate, females were found to be significantly more resistant and aggressive toward infected males than control males. Male aggression, on the other hand, was greater in pairs that did result in mating. These results suggest that sexual conflict in mating can be related to infection status, and that females can recognize infected males and alter their behavior in response.

A trade-off in evolution: the adaptive landscape of spiders without venom glands.

Venom glands play a key role in the predation and defense strategies of almost all spider groups. However, the spider family Uloboridae lacks venom glands and has evolved an adaptive strategy: they excessively wrap their prey directly with spider silk instead of paralyzing it first with toxins. This shift in survival strategy is very fascinating, but the genetic underpinnings behind it are poorly understood. Spanning multiple spider groups, we conducted multiomics analyses on Octonoba sinensis and described the adaptive evolution of the Uloboridae family at the genome level. We observed the coding genes of myosin and twitchin in muscles are under positive selection, energy metabolism functions are enhanced, and gene families related to tracheal development and tissue mechanical strength are expanded or emerged, all of which are related to the unique anatomical structure and predatory behavior of spiders in the family Uloboridae. In addition, we also scanned the elements that are absent or under relaxed purifying selection, as well as toxin gene homologs in the genomes of 2 species in this family. The results show that the absence of regions and regions under relaxed selection in these spiders' genomes are concentrated in areas related to development and neurosystem. The search for toxin homologs reveals possible gene function shift between toxins and nontoxins and confirms that there are no reliable toxin genes in the genome of this group. This study demonstrates the trade-off between different predation strategies in spiders, using either chemical or physical strategy, and provides insights into the possible mechanism underlying this trade-off. Venomless spiders need to mobilize multiple developmental and metabolic pathways related to motor function and limb mechanical strength to cover the decline in adaptability caused by the absence of venom glands.

Single-cell transcriptomics reveals the brain evolution of web-building spiders

Spiders are renowned for their efficient capture of flying insects using intricate aerial webs. How the spider nervous systems evolved to cope with this specialized hunting strategy and various environmental clues in an aerial space remains unknown. Here we report a brain-cell atlas of >30,000 single-cell transcriptomes from a web-building spider (Hylyphantes graminicola). Our analysis revealed the preservation of ancestral neuron types in spiders, including the potential coexistence of noradrenergic and octopaminergic neurons, and many peptidergic neuronal types that are lost in insects. By comparing the genome of two newly sequenced plesiomorphic burrowing spiders with three aerial web-building spiders, we found that the positively selected genes in the ancestral branch of web-building spiders were preferentially expressed (42%) in the brain, especially in the three mushroom body-like neuronal types. By gene enrichment analysis and RNAi experiments, these genes were suggested to be involved in the learning and memory pathway and may influence the spiders’ web-building and hunting behaviour. Our results provide key sources for understanding the evolution of behaviour in spiders and reveal how molecular evolution drives neuron innovation and the diversification of associated complex behaviours.

Comparison of Spider-Robot Information Models

The paper deduces a mathematical model of a spider-robot with six three-link limbs. Many limbs with a multi-link structure greatly complicate the process of synthesizing a model, since in total the robot has twenty-four degrees of freedom, i.e., three coordinates of the center of mass of the body in space, three angles of rotation of the body relative to its center of mass and three degrees of freedom for each limb, to describe the position of the links. The derived mathematical model is based on the Lagrange equations with a further transformation of the equations to the Cauchy normal form in a matrix form. To test the resulting model in a SimInTech environment, an information model is synthesized and two simple experiments ar carried out to simulate the behavior of real spiders: moving forward in a straight line and turning in place at a given angle. The experimental results demonstrate that the synthesized information model can well cope with the tasks and the mathematical model underlying it can be used for further research.

A road map of jumping spider behavior

A road map of jumping spider behavior

Locomotor behaviour of tropical wolf spiders is affected by external temperature and body size, not load bearing

Locomotor behaviour of tropical wolf spiders is affected by external temperature and body size, not load bearing

Transcriptome Changes Reveal the Toxic Mechanism of Cadmium and Lead Combined Exposure on Silk Production and Web-Weaving Behavior of Spider A. ventricosus.

The combined exposure of multiple metals imposes a substantial burden on the ecophysiological functions in organisms; however, the precise mechanism(s) remains largely unknown. Here, adult female A. ventricosus were exposed to single and combined exposure to cadmium (Cd) and lead (Pb) through the food chain. The aim was to explore the combined toxicity of these metals on silk production and web-weaving behavior at physiological, cellular morphological, and transcriptomic levels. The Cd and Pb combined exposure significantly inhibited the ability of silk production and web-weaving, including reduced silk fiber weight and diameter of single strands, lowered weaving position, induced nocturnal weaving, and increased instances of no-web, and showed a dose-response relationship on the Cd and Pb bioaccumulation. Concurrently, severe oxidative stress and degenerative changes in cells were observed. In addition, the combined pollution of Cd and Pb demonstrated synergistic effects, influenced by variations in concentration, on the enrichment of metals, inhibition of silk weight, oxidative damage, and cellular degeneration. At the transcriptome level, the upregulated ampullate spidroin genes and downregulated amino acid anabolic genes, upregulated Far genes and downregulated cytoskeleton-related TUBA genes, and overexpressed AChE and Glu genes may tend to present promising potential as biomarkers for silk protein synthesis, cellular degeneration, and neurotransmitter induction. This study offers an enormous capability for a comprehensive understanding of the eco-toxicological effects and mechanisms of multiheavy metals pollution.

Bioinspired “cage traps” for closed-loop lead management of perovskite solar cells under real-world contamination assessment

Despite the remarkable progress made in perovskite solar cells, great concerns regarding potential Pb contamination risk and environmental vulnerability risks associated with perovskite solar cells pose a significant obstacle to their real-world commercialization. In this study, we took inspiration from the ensnaring prey behavior of spiders and chemical components in spider web to strategically implant a multifunctional mesoporous amino-grafted-carbon net into perovskite solar cells, creating a biomimetic cage traps that could effectively mitigate Pb leakage and shield the external invasion under extreme weather conditions. The synergistic Pb capturing mechanism in terms of chemical chelation and physical adsorption is in-depth explored. Additionally, the Pb contamination assessment of end-of-life perovskite solar cells in the real-world ecosystem, including Yellow River water and soil, is proposed. The sustainable closed-loop Pb management process is also successfully established involving four critical steps: Pb precipitation, Pb adsorption, Pb desorption, and Pb recycling. Our findings provide inspiring insights for promoting green and sustainable industrialization of perovskite solar cells.

WebGripper: Bioinspired Cobweb Soft Gripper for Adaptable and Stable Grasping

Web structure is a flexible structure widely used in animal predation behavior and human hunting work, which exhibits an excellent capability of gripping objects stably and securely. Inspired by the predation behavior of spiders, in this article, we present a bioinspired cobweb soft gripper, named WebGripper, which takes on a form like a spider web before grasping an object and presents an entangling state like a snake after grasping the object. These characteristics result in broad adaptability to various objects and enhanced grasping stability. The design concept, grasping principle, and fabrication process of the WebGripper are presented in this work, and the influences of cable layout and soft finger installation angle are analyzed to provide a reference for the design of the WebGripper. To evaluate the performance of the WebGripper, we carried out experiments on grasping objects with different shapes and sizes. Experimental results illustrated the universal adaptable grasping ability of the WebGripper, which exhibits excellent application prospects in many fields, such as goods sorting, fruit picking, and underwater fishing. This work is expected to promote the development of a high-performance soft gripper that may be used in a number of applications based on the understanding of the bionic web structure.