Beetle-robot hybrid interaction: sex, lateralization and mating experience modulate behavioural responses to robotic cues in the larger grain borer Prostephanus truncatus (Horn)

Lateralized courtship behavior in Ostrinia furnacalis (Lepidoptera: Crambidae): influence of gender, sexual experience, and its effects on mating success

Lateralization in mating behavior is increasingly recognized as a significant trait in insect species, yet its influence associated with gender, and sexual experience in Ostrinia furnacalis (Guenée) remains poorly understood. This study examines how lateralized mating behaviors, gender, and sexual experience interact to influence mating success and efficiency in O. furnacalis. We conducted controlled mating trials to assess how gender and sexual experience shape lateralized directional approaches (eg right- or left-biased) and turnings (eg 180° right- or left-biased) across the pre-copulatory, copulatory, and post-copulatory phases. Our results indicated that, in terms of gender, males were more likely to approach females, whereas females rarely initiated approaches, with both approaches each other simultaneously being infrequent. Both virgin and experienced males showed higher right-biased directional approaches than the front approaches to the females with more left-biased directional turns for successful intromissive copulation. Experienced males showed greater mating success than virgins. In contrast, experienced females exhibited lower mating success and longer post-copulatory interactions compared to virgin females, particularly duration of copulation. Post-copulatory interactions showed that antennal touching occurred more frequently in the experienced pairs. This study is the first to demonstrate the combined influence of gender and sexual experience on lateralized mating dynamics, with male courtship behaviors linked to learning processes. The results indicate that sexual experience, potentially involving learning and memory processes, significantly enhances mating efficiency and fitness in O. furnacalis. This research provides a more nuanced understanding of lateralized mating behaviors in O. furnacalis, with implications for refining pest management strategies in agricultural environments.

Tapping for love: courtship, mating, and behavioral asymmetry in two aphid parasitoids, Aphidius ervi and Aphidius matricariae (Hymenoptera: Braconidae: Aphidiinae)

Understanding the biology and ecology of parasitoids can have direct implications for their evaluation as biological control agents, as well as for the development and implementation of mass-rearing techniques. Nonetheless, our current knowledge of the possible influence of lateralized displays (i.e., the asymmetric expression of cognitive functions) on their reproductive behavior is scarce. Herein, we characterized the behavioral elements involved in courtship, and quantified the durations of 2 important aphid parasitoids, Aphidius ervi Haliday and Aphidius matricariae Haliday (Hymenoptera: Braconidae: Aphidiinae). We quantified the main indicators of copulation and examined the occurrence of lateralized traits at population level. Results indicated that A. matricariae exhibited longer durations of wing fanning, antennal tapping, pre-copula and copula phases compared to A. ervi. Postcopulatory behavior was observed only in A. matricariae. Unlike other parasitoid species, the duration of wing fanning, chasing, and antennal tapping did not affect the success of the mating of male A. ervi and A. matricariae. Both species exhibited a right-biased female kicking behavior at the population level during the pre-copula. Our study provides insights into the fundamental biology of aphidiine parasitoids and reports the presence of population-level lateralized mating displays, which can serve as useful benchmarks to evaluate the quality of mass-rearing systems.

Receiver response to high-intensity courtship differs with courter status in spotted bowerbirds Ptilonorhynchus maculatus

Understanding sexual communication requires assessing the behaviour of both the sender and the receiver. Receiver responses to sexual displays carry relevant information, but such signals or cues may be subtle and therefore technically challenging to investigate. Here, we focus on receiver body movements in response to high-intensity courtship in spotted bowerbirds (Ptilonorhynchus maculatus). Male bowerbirds perform a vigorous courtship choreography on dedicated display structures-bowers. Bower owners tolerate other non-territorial males at their bowers, yet the courtship displays of these so-called 'subordinate' males rarely result in successful copulations. Males that display at high intensity are preferred by females in this species, yet excessively aggressive displays may be threatening, hence scaring prospective mates away. In this study, we hypothesized that bower owners are better able to exhibit high-intensity movements without startling their audience compared with subordinate males. To address this question, we used a combination of behavioural coding and AI-based tracking of body movements, which allows precise spatial and temporal resolution for the study of subtle behavioural responses. Contrary to our predictions, we found that bower owners evoked stronger startle responses than subordinate males. We discuss these unexpected results and suggest further experimental approaches for future investigations.

Lateralised courtship behaviour and its impact on mating success in Ostrinia furnacalis (Lepidoptera: Crambidae)

Lateralisation is a well-established phenomenon observed in an increasing number of insect species. This study aims to obtain basic details on lateralisation in courtship and mating behaviour in Ostrinia furnacalis, the Asian corn borer. We conducted laboratory investigations to observe lateralisation in courtship and mating behaviours in adult O. furnacalis. Our goal was also to detect lateralised mating behaviour variations during sexual interactions and to elucidate how these variances might influence the mating success of males. Our findings reveal two distinct lateralised traits: male approaches from the right or left side of the female and the direction of male turning displays. Specifically, males approaching females from their right side predominantly exhibited left-biased 180° turning displays, while males approaching females from the left-side primarily displayed right-biased 180° turning displays. Notably, left-biased males, executing a 180° turn for end-to-end genital contact, initiated copulation with fewer attempts and began copulation earlier than their right-biased approaches with left-biased 180° turning displays. Furthermore, mating success was higher when males subsequently approached the right side of females during sexual encounters. Left-biased 180° turning males exhibited a higher number of successful mating interactions. These observations provide the first report on lateralisation in the reproductive behaviour of O. furnacalis under controlled laboratory conditions and hold promise for establishing reliable benchmarks for assessing and monitoring the quality of mass-produced individuals in pest control efforts.

Bioinspired robots can foster nature conservation

We live in a time of unprecedented scientific and human progress while being increasingly aware of its negative impacts on our planet's health. Aerial, terrestrial, and aquatic ecosystems have significantly declined putting us on course to a sixth mass extinction event. Nonetheless, the advances made in science, engineering, and technology have given us the opportunity to reverse some of our ecosystem damage and preserve them through conservation efforts around the world. However, current conservation efforts are primarily human led with assistance from conventional robotic systems which limit their scope and effectiveness, along with negatively impacting the surroundings. In this perspective, we present the field of bioinspired robotics to develop versatile agents for future conservation efforts that can operate in the natural environment while minimizing the disturbance/impact to its inhabitants and the environment's natural state. We provide an operational and environmental framework that should be considered while developing bioinspired robots for conservation. These considerations go beyond addressing the challenges of human-led conservation efforts and leverage the advancements in the field of materials, intelligence, and energy harvesting, to make bioinspired robots move and sense like animals. In doing so, it makes bioinspired robots an attractive, non-invasive, sustainable, and effective conservation tool for exploration, data collection, intervention, and maintenance tasks. Finally, we discuss the development of bioinspired robots in the context of collaboration, practicality, and applicability that would ensure their further development and widespread use to protect and preserve our natural world.

Lateralized Movements during the Mating Behavior, Which Are Associated with Sex and Sexual Experience, Increase the Mating Success in Alphitobius diaperinus (Coleoptera: Tenebrionidae)

In the present study, we explored the effects of displacement directionality in mating behavior (i.e., lateralized and non-lateralized movements) on mating success (i.e., copulation occurs) and efficiency (i.e., time length at which copulation is achieved), and its association with sex and sexual experience in A. diaperinus. To do so, we carried out mating experiments and recorded the behavior of the mating pair during the whole mating sequence (i.e., precopulatory and copulatory phases). During the precopulatory phase, independently of sex and sexual experience, all beetles performed non-lateralized (i.e., backside or frontside) approaches; however, only sexually experienced beetles showed lateralized approaches (i.e., right-side and left-side). Notably, experienced males exhibited greater mating success than virgin males. After the approach, both virgin and experienced males displayed lateralized and non-lateralized mounts on the females with distinct mating success. Regardless of their sexual experience, 100% of successful mating attempts were achieved when males mounted from the females' right side. Furthermore, the development of lateralized approaches and mounts reduces the time of mating sequence span compared with non-lateralized behaviors. We highlight the importance of lateralization in mating behavior and sexual experience to achieve higher mating success, addressing a potential learning ability of beetles based on experience.

The hybrid bio-robotic swarm as a powerful tool for collective motion research: a perspective

Swarming or collective motion is ubiquitous in natural systems, and instrumental in many technological applications. Accordingly, research interest in this phenomenon is crossing discipline boundaries. A common major question is that of the intricate interactions between the individual, the group, and the environment. There are, however, major gaps in our understanding of swarming systems, very often due to the theoretical difficulty of relating embodied properties to the physical agents-individual animals or robots. Recently, there has been much progress in exploiting the complementary nature of the two disciplines: biology and robotics. This, unfortunately, is still uncommon in swarm research. Specifically, there are very few examples of joint research programs that investigate multiple biological and synthetic agents concomitantly. Here we present a novel research tool, enabling a unique, tightly integrated, bio-inspired, and robot-assisted study of major questions in swarm collective motion. Utilizing a quintessential model of collective behavior-locust nymphs and our recently developed Nymbots (locust-inspired robots)-we focus on fundamental questions and gaps in the scientific understanding of swarms, providing novel interdisciplinary insights and sharing ideas disciplines. The Nymbot-Locust bio-hybrid swarm enables the investigation of biology hypotheses that would be otherwise difficult, or even impossible to test, and to discover technological insights that might otherwise remain hidden from view.

Exploring the advantages of using artificial agents to investigate animacy perception in cats and dogs

Self-propelled motion cues elicit the perception of inanimate objects as animate. Studies usually rely on the looking behaviour of subjects towards stimuli displayed on a screen, but utilizing artificial unidentified moving objects (UMOs) provides a more natural, interactive context. Here, we investigated whether cats and dogs discriminate between UMOs showing animate vs inanimate motion, and how they react to the UMOs' interactive behaviour. Subjects first observed, in turn, the motion of an animate and an inanimate UMO, and then they could move freely for 2 min while both UMOs were present (two-way choice phase). In the following specific motion phase, the animate UMO showed one of three interactive behaviours: pushing a ball, a luring motion, or moving towards the subject (between-subject design). Then, subjects could move freely for 2 min again while the UMO was motionless. At the end, subjects were free to move in the room while the UMO was moving semi-randomly in the room. We found that dogs approached and touched the UMO(s) sooner and more frequently than cats, regardless of the context. In the two-way choice phase, dogs looked at the animate UMO more often, and both species touched the animate UMO more frequently. However, whether the UMO showed playing, luring or assertive behaviour did not influence subjects' behaviour. In summary, both species displayed distinctive behaviour towards the animate UMO, but in dogs, in addition to the physical contact this was also reflected by the looking behaviour. Overall, dogs were more keen to explore and interact with the UMO than cats, which might be due to the general increased stress of cats in novel environments. The findings indicate the importance of measuring multiple behaviours when assessing responses to animacy. The live demonstration using artificial agents provides a unique opportunity to study social perception in nonhuman species.

Functional Asymmetries Routing the Mating Behavior of the Rusty Grain Beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae)

Simple Summary

We evaluated the behavioral asymmetries of Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae) males during courtship and mating with potential mates. The highest proportion of males showed left-biased approaches towards females, and turned 180° to their left. Right-biased males (i.e., approaching mates from the right and then turning 180°) were fewer than left-biased males. A low percentage of males approaching from the front and back side achieved successful mating. Left-biased-approaching males had a significantly shorter copula duration in comparison with other males. Left-biased males performed shorter copulation attempts and copula in comparison to right-biased males. This research contributes to understand the role of lateralization in the beetle family Laemophloeidae.

Abstract

The rusty grain beetle, Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), is a serious secondary pest of stored and processed food commodities. In the present study, we investigated the lateralization of males during courtship and mating, attempting to understand if it can be linked with a high likelihood of successful copulation. Most males exhibited left-biased (41%) approaches towards females, and turned 180° to their left, with 37% mating success. Right-biased males (i.e., approaching from the right and then turning 180°) were fewer than left-biased ones; 26% out of 34% managed to copulate with females. Only 9% out of 13% and 7% out of 11% of the back side- and front side-approaching males succeeded in mating, respectively. Directional asymmetries in approaching a potential mate, as well as the laterality of side-biased turning 180°, significantly affected male copulation success, with left-biased males achieving higher mating success if compared to right-biased males. Copula duration was significantly lower for left-biased-approaching males (1668.0 s) over the others (i.e., 1808.1, 1767.9 and 1746.9 for right-biased, front and back side-males, respectively). Left-biased males performed shorter copulation attempts and copula compared to right-biased males. Overall, our study adds basic knowledge to the lateralized behavioral displays during courtship and copula of C. ferrugineus.

Bio-Inspired Control System for Fingers Actuated by Multiple SMA Actuators

Spiking neural networks are able to control with high precision the rotation and force of single-joint robotic arms when shape memory alloy wires are used for actuation. Bio-inspired robotic arms such as anthropomorphic fingers include more junctions that are actuated simultaneously. Starting from the hypothesis that the motor cortex groups the control of multiple muscles into neural synergies, this work presents for the first time an SNN structure that is able to control a series of finger motions by activation of groups of neurons that drive the corresponding actuators in sequence. The initial motion starts when a command signal is received, while the subsequent ones are initiated based on the sensors’ output. In order to increase the biological plausibility of the control system, the finger is flexed and extended by four SMA wires connected to the phalanges as the main tendons. The results show that the artificial finger that is controlled by the SNN is able to smoothly perform several motions of the human index finger while the command signal is active. To evaluate the advantages of using SNN, we compared the finger behaviours when the SMA actuators are driven by SNN, and by a microcontroller, respectively. In addition, we designed an electronic circuit that models the sensor’s output in concordance with the SNN output.

Functional Symmetry after Surgical Treatment of Pertrochanteric Fractures in the Elderly

Pertrochanteric fractures (PFs) in the elderly and their consequences are among the leading causes of disability; they significantly reduce the quality of life and lead to loss of independence. This article aims to determine the functional and radiological outcomes in a group of patients with PFs treated with either the Dynamic hip screw (DHS) or intramedullary Gamma nail fixation. A total of 618 patients, admitted to hospital for pertrochanteric fractures between 2015 and 2019, at a mean age of 82.40 (range 29–104) were screened. Finally, 78 patients were enrolled. Parameters related to hospital stay and surgery (length of hospital stay, surgery duration) were compared in both groups. Functional outcomes were assessed by the Harris hip score, subjective pain was measured with a visual analogue scale (VAS), and quality of life was evaluated using the EQ-5D-5L questionnaire. The obtained results were evaluated at 3- and 6-month follow-up. Radiographic parameters were measured based on the preoperative and postoperative standing anterior–posterior pelvic radiographs and axial projection of the hip at 6-month follow-up. The results showed no significant difference between groups treated either with DHS or intramedullary Gamma nail fixation within the scope of the variables under study. In conclusion, both analysed methods support the functional symmetry of the musculoskeletal system.

Lateralization of Courtship Traits Impacts Pentatomid Male Mating Success—Evidence from Field Observations

Simple Summary

Although a growing number of studies have reported asymmetries of brain and behavior in various insect orders, detailed information on lateralization in the courtship and mating behavior of insects in the wild is scarce. In this research, we studied the courtship and mating behavior of the neem bug, Halys dentatus, in the field, quantifying lateralized behavioral displays, and assessing their impact on male mating success. A population-level lateralization in males approaching females was found. Furthermore, the male mating success was affected by lateralization; right-biased males achieved higher mating success rates. Overall, our results add useful knowledge on the reproductive behavior of H. dentatus in the field, with potential applications for identifying useful benchmarks to monitor the quality of individuals mass-reared for pest control purposes over time. This study furtherly highlights the role of lateralized traits in determining male mating success in insects.

Abstract

Lateralization has been documented in many insect species, but limited information on courtship and mating lateralization in wild conditions is available. We conducted field investigation on the courtship and mating behavior of the neem bug, Halys dentatus, a polyphagous insect mainly infesting Azadirachta indica, with particular attention to lateralization of mating displays. We investigated the presence of population-level behavioral asymmetries during H. dentatus sexual interactions and their influence on male mating success. Two lateralized traits were found: left or right-biased male approaches to the female and left or right-biased male turning displays. Males approaching females from their left side were mainly right-biased in the 180° turning display, and males that approached females from their right side were mainly left-biased. Right-biased males by turning 180° to carry out end-to-end genital contact, performed a lower number of copulation attempts, thus starting copula earlier than left-biased males. Mating success was higher when males approached the left side of females during sexual interactions. A higher number of successful mating interactions was observed in right-biased males when turning 180°. Our results add useful knowledge on the reproductive behavior of H. dentatus in the field, with potential applications for identifying useful benchmarks to monitor the quality of individuals mass-reared for pest control purposes over time.

Robot-Fish Interaction Helps to Trigger Social Buffering in Neon Tetras: The Potential Role of Social Robotics in Treating Anxiety

The emerging field of social robotics comprises several multidisciplinary applications. Anxiety and stress therapies can greatly benefit by socio-emotional support provided by robots, although the intervention of social robots as effective treatment needs to be fully understood. Herein, Paracheirodon innesi, a social fish species, was used to interact with a robotic fish to understand intrinsic and extrinsic mechanisms causing anxiety, and how social robots can be effectively used as anxiety treatments. In the first experiment we tested the effects of a conspecific-mimicking robot on the fish tendency to swim in the bottom when transferred in a new tank. Here, P. innesi spent a significantly longer time in the upper section of the test tank when the robotic fish was present, clearly indicating a reduction of their state of anxiety due to social stimuli. The second experiment was based on a modification of the dark/light preference test, since many teleost fish are scototactic, preferring dark environments. However, when the robotic fish was placed in the white half of the test tank, P. innesi individuals swam longer in this section otherwise aversive. Social support provided by the robotic fish in both experiments produced a better recovery from anxiety due to social buffering, a phenomenon regulated by specific neural mechanisms. This study provides new insights on the evolution and mechanisms of social buffering to reduce anxiety, as well as on the use of social robots as an alternative to traditional approaches in treating anxiety symptoms.

Archerfish respond to a hunting robotic conspecific

While the unique hunting behavior of archerfish has received considerable scientific attention, the specific social cues that govern behaviors like intraspecific kleptoparasitism in the species are less understood. This paper asks whether the use of a robotic facsimile representing an archerfish can elicit a social response if it approximates an archerfish's appearance, along with key features of its hunting behavior. We found that the fish respond to the robot when it hunted, as indicated by decreasing distances between the robot and fish (and among the fish) during the robot's hunting behavior sequence, as well as higher net transfer entropy when the robot was hunting. These effects were present even when the robot's "hunt" was unproductive and did not result in food. The temporal pattern of fish approach to the robot and each other indicated that the segment of robot hunting behavior proximal to the robotic facsimile shot elicited fish behavior initially. However, earlier cues in the robot's hunting sequence became important following more experience with a food contingency. This indicates that further studies could use a robotic facsimile to conduct a detailed stimulus analysis, changing aspects of the robot's appearance and behavior to uncover the basic mechanisms of information transfer among individuals in a social hunting scenario.

Unveiling social distancing mechanisms via a fish-robot hybrid interaction

Pathogen transmission is a major limit of social species. Social distancing, a behavioural-based response to diseases, has been regularly reported in nature. However, the identification of distinctive stimuli associated with an infectious disease represents a challenging task for host species, whose cognitive mechanisms are still poorly understood. Herein, the social fish Paracheirodon innesi, was selected as model organism to investigate animal abilities in exploiting visual information to identify and promote social distancing towards potentially infected conspecifics. To address this, a robotic fish replica mimicking a healthy P. innesi subject, and another mimicking P. innesi with morphological and/or locomotion anomalies were developed. P. innesi individuals were attracted by the healthy fish replica, while they avoided the fish replica with morphological abnormalities, as well as the fish replica with an intact appearance, but performing locomotion anomalies (both symptoms associated with a microsporidian parasite infesting P. innesi and other fish). Furthermore, the fish replica presenting both morphology and locomotion anomalies in conjunction, triggered a significantly stronger social distancing response. This confirms the hypothesis that group living animals overgeneralize cues that can be related with a disease to minimize transmission, and highlights the important role of visual cues in infection risk contexts. This study prompts more attention on the role of behavioural-based strategies to avoid pathogen/parasite diffusion, and can be used to optimize computational approaches to model disease dynamics.

Insect-Inspired Robots: Bridging Biological and Artificial Systems

This review article aims to address common research questions in hexapod robotics. How can we build intelligent autonomous hexapod robots that can exploit their biomechanics, morphology, and computational systems, to achieve autonomy, adaptability, and energy efficiency comparable to small living creatures, such as insects? Are insects good models for building such intelligent hexapod robots because they are the only animals with six legs? This review article is divided into three main sections to address these questions, as well as to assist roboticists in identifying relevant and future directions in the field of hexapod robotics over the next decade. After an introduction in section (1), the sections will respectively cover the following three key areas: (2) biomechanics focused on the design of smart legs; (3) locomotion control; and (4) high-level cognition control. These interconnected and interdependent areas are all crucial to improving the level of performance of hexapod robotics in terms of energy efficiency, terrain adaptability, autonomy, and operational range. We will also discuss how the next generation of bioroboticists will be able to transfer knowledge from biology to robotics and vice versa.

Motion Control of a Gecko-like Robot Based on a Central Pattern Generator

To solve the problem of the motion control of gecko-like robots in complex environments, a central pattern generator (CPG) network model of motion control was designed. The CPG oscillation model was first constructed using a sinusoidal function, resulting in stable rhythm control signals for each joint of the gecko-like robot. Subsequently, the gecko-like robot successfully walked, crossed obstacles and climbed steps in the vertical plane, based on stable rhythm control signals. Both simulations and experiments validating the feasibility of the proposed CPG motion control model are presented.

Chronic ciprofloxacin and atrazine co-exposure aggravates locomotor and exploratory deficits in non-target detritivore speckled cockroach (Nauphoeta cinerea)

The global detection of ciprofloxacin and atrazine in soil is linked to intensive anthropogenic activities in agriculture and inadvertent discharge of industrial wastes to the environment. Nauphoeta cinerea is a terrestrial insect with cosmopolitan distribution and great environmental function. The current study probed the neurobehavioral and cellular responses of N. cinerea singly and jointly exposed to atrazine (1.0 and 0.5 μg g^-1 feed) and ciprofloxacin (0.5 and 0.25 μg g^-1 feed) for 63 days. Results demonstrated that the reductions in the body rotation, maximum speed, turn angle, path efficiency, distance traveled, episodes, and time of mobility induced by atrazine or ciprofloxacin per se was exacerbated in the co-exposure group. The altered exploratory and locomotor in insects singly and jointly exposed to ciprofloxacin and atrazine were verified by track plots and heat maps. Furthermore, we observed a decrease in acetylcholinesterase and anti-oxidative enzyme activities with concomitant elevation in the levels of lipid peroxidation, nitric oxide, and reactive oxygen and nitrogen species were significantly intensified in the midgut, hemolymph, and head of insects co-exposed to ciprofloxacin and atrazine. In conclusion, exposure to binary mixtures of ciprofloxacin and atrazine elicited greater locomotor and exploratory deficits than upon exposure to the individual compound by inhibiting acetylcholinesterase activity and induction of oxido-inflammatory stress responses in the insects. N. cinerea may be a usable model insect for checking contaminants of ecological risks.

Tephritid Fruit Fly Semiochemicals: Current Knowledge and Future Perspectives

The Dipteran family Tephritidae (true fruit flies) comprises more than 5000 species classified in 500 genera distributed worldwide. Tephritidae include devastating agricultural pests and highly invasive species whose spread is currently facilitated by globalization, international trade and human mobility. The ability to identify and exploit a wide range of host plants for oviposition, as well as effective and diversified reproductive strategies, are among the key features supporting tephritid biological success. Intraspecific communication involves the exchange of a complex set of sensory cues that are species- and sex-specific. Chemical signals, which are standing out in tephritid communication, comprise long-distance pheromones emitted by one or both sexes, cuticular hydrocarbons with limited volatility deposited on the surrounding substrate or on the insect body regulating medium- to short-distance communication, and host-marking compounds deposited on the fruit after oviposition. In this review, the current knowledge on tephritid chemical communication was analysed with a special emphasis on fruit fly pest species belonging to the Anastrepha, Bactrocera, Ceratitis, and Rhagoletis genera. The multidisciplinary approaches adopted for characterising tephritid semiochemicals, and the real-world applications and challenges for Integrated Pest Management (IPM) and biological control strategies are critically discussed. Future perspectives for targeted research on fruit fly chemical communication are highlighted.

Navigation of a Freely Walking Fruit Fly in Infinite Space Using a Transparent Omnidirectional Locomotion Compensator (TOLC)

Animal behavior is an essential element in behavioral neuroscience study. However, most behavior studies in small animals such as fruit flies (Drosophilamelanogaster) have been performed in a limited spatial chamber or by tethering the fly's body on a fixture, which restricts its natural behavior. In this paper, we developed the Transparent Omnidirectional Locomotion Compensator (TOLC) for a freely walking fruit fly without tethering, which enables its navigation in infinite space. The TOLC maintains a position of a fruit fly by compensating its motion using the transparent sphere. The TOLC is capable of maintaining the position error < 1 mm for 90.3% of the time and the heading error < 5° for 80.2% of the time. The inverted imaging system with a transparent sphere secures the space for an additional experimental apparatus. Because the proposed TOLC allows us to observe a freely walking fly without physical tethering, there is no potential injury during the experiment. Thus, the TOLC will offer a unique opportunity to investigate longitudinal studies of a wide range of behavior in an unrestricted walking Drosophila.

Behavioral Asymmetries Affecting Male Mating Success in Tenebrio molitor (Coleoptera: Tenebrionidae), an Important Edible Species

The yellow mealworm, Tenebrio molitor L., is one of the most significant insect species of economic importance for producing protein-rich food and feed. The larvae are a promising fishmeal substitute for fish feed, and a good alternative source for human nutrition. In this study, the effect of behavioral asymmetries on male mating success of T. molitor was evaluated. Males performing antennal waving (63%) when detecting a female approached the apex of the female abdomen in a comparable manner from both sides (32% from left side vs 31% from right side). Fewer males showed antennal waving and also raised the anterior part of their body (37%) during mate recognition; 14% of them approached on the apex of female abdomen from the left side, and 23% of them approached from the right side of female body. The duration of mate recognition, antennal tapping, rubbing behavior, and the whole mating sequence of males that moved on the apex of the abdomen from the left side of females was significantly lower over that of males approaching from the right side (10.7, 12.6, 16.4, and 126.1 s for left-biased males vs 12.2, 14.8, 18.6, and 139.6 s for right-biased males, respectively). Concerning mounting side, left-biased males showed a shorter duration of rubbing behavior and the whole mating sequence (15.5 and 123.2 s) over right-biased (18.9 and 138.3 s) and backside approaching males (19.4 and 144.1 s). The duration of mate recognition, antennal tapping, and copula was not affected by the presence of a male laterality bias. Overall, this study sheds light on how laterality affects mating traits and the male success of this important edible insect species.

Phormica: Photochromic Pheromone Release and Detection System for Stigmergic Coordination in Robot Swarms

Stigmergy is a form of indirect communication and coordination in which agents modify the environment to pass information to their peers. In nature, animals use stigmergy by, for example, releasing pheromone that conveys information to other members of their species. A few systems in swarm robotics research have replicated this process by introducing the concept of artificial pheromone. In this paper, we present Phormica, a system to conduct experiments in swarm robotics that enables a swarm of e-puck robots to release and detect artificial pheromone. Phormica emulates pheromone-based stigmergy thanks to the ability of robots to project UV light on the ground, which has been previously covered with a photochromic material. As a proof of concept, we test Phormica on three collective missions in which robots act collectively guided by the artificial pheromone they release and detect. Experimental results indicate that a robot swarm can effectively self-organize and act collectively by using stigmergic coordination based on the artificial pheromone provided by Phormica.

Bio-robotic cues show how the Trinidadian guppy male recognises the morphological features of receptive females

Sensory fusion is used by the males of several animal species to discriminate the mating status of females by evaluating their phenotypic traits. The predominant trait used is olfactory cues, and the role of visual cues is not yet fully understood. The ability of Poecilia reticulata males to evaluate females' receptivity based on visual cues was investigated. Guppy males adopt two different mating strategies, courtship displays and forced copulation, towards receptive and pregnant females, respectively. Robotic counterparts mimicking receptive and pregnant females were developed to test whether males relied only on visual information to determine a females' mating status. Exposure to the robotic receptive females evoked courtship behaviours, while forced copulation attempts were more frequent towards the robotic pregnant females. When the robotic fish were simultaneously exposed, regardless of the presence or absence of receptive-female olfactory cues, males expressed their preference for the receptive female. Visual processing showed that fish social interactions played a strategic role in their collection of information, especially when other stimuli were not available. The proposed ethorobotic approach allowed for assessing the role of visual cues in the mating choice of P. reticulata males and highlighting the information processing methods and cognition in aquatic animals.