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Social traits are expected to experience highly context-dependent selection, but we know little about the contextual factors that shape selection on social behaviours. We hypothesized that the fitness consequences of social interactions will depend on the age of social partners, and therefore that population age structure will shape evolutionary pressures on sociality. Here, we investigate the consequences of age variation at multiple levels of social organization for both individual fitness and sexual selection on social network traits. We experimentally manipulated the age composition of populations of the forked fungus beetle Bolitotherus cornutus, creating 12 replicate populations with either young or old age structures. We found that fitness is associated with variance in age at three different levels of organization: the individual, interacting social partners, and the population. Older individuals have higher reproductive success, males pay a fitness cost when they interact with old males and females achieve lower fitness in older populations. In addition to influencing fitness, population age structure also altered the selection acting on social network position in females. Female sociality is under positive selection only in old populations. Our results highlight age structure as an understudied demographic variable shaping the landscape of selection on social behaviour. This article is part of the discussion meeting issue 'Understanding age and society using natural populations'. [ABSTRACT FROM AUTHOR]

Random search theories predict that animals employ movement patterns that optimize encounter rates with target resources. However, animals are not always able to achieve the best search strategy. Energy depletion, for example, limits searchers' movement activities, forcing them to adjust their behaviors before and after encounters. Here, we investigate the cost of mate search in a termite, Reticulitermes speratus , and reveal that the costs associated with mate finding reduce the selectivity of mating partners. After a dispersal flight, termites search for a mating partner with limited reserved energy. We found that their movement activity and diffusiveness progressively declined over extended mate search. Our data-based simulations qualitatively confirmed that the reduced movement diffusiveness decreased the searching efficiency. Also, prolonged search periods reduced survival rate and the number of offspring. Thus, mate search has two different negative effects on termites. Finally, we found that termites with an extended mate search reduced the selectivity of mating partners, where males immediately paired with any encountering females. Thus, termites dramatically changed their mate search behavior depending on their internal states. Our finding highlights that accounting for the searchers' internal states is essential to fill the gap between random search theories and empirical behavioral observations. [ABSTRACT FROM AUTHOR]

The microbiota of mosquitoes influences many aspects of their biology, including developmental processes, mating and sexual reproduction, immune functions, and refractoriness to pathogens. Here, we considered their role in resistance against insecticides. In particular, we assessed how larval infection of a permethrin-resistant and a sensitive colony of Anopheles gambiae by four strains belonging to three different Pseudomonas species affects several life history traits and the impact of the insecticide on adult mortality. Our data showed that all four Pseudomonas strains persisted in adults until death. The bacteria increased the likelihood that mosquitoes survived 24 h after exposure to permethrin by up to twofold. The impact of the bacteria depended on the bacterial strains and the mosquito colony: in the resistant colony, all bacteria increased survival by about twofold, while in the sensitive colony, only two of the four strains increased survival. The benefit concerning insecticide resistance came with little to no impact on the other traits (i.e., larval mortality, developmental time and adult longevity). Altogether, our results highlight the importance of considering environmental microbial exposure and mosquito microbial communities in epidemiological and vector-control studies, while also suggesting a possible role for Pseudomonas spp. as a symbiont in A. gambiae. [ABSTRACT FROM AUTHOR]

Macaques are widely distributed in Thailand with remarkable adaptation to living close to humans in residential, religious sites, markets and tourist areas. They play an essential role in the persistence of pathogens in the environment. As reservoir hosts, they are exposed to hematophagous vectors that secrete saliva, a cocktail of bioactive molecules including antigenic components stimulating host antibody production. Subsequent to the detection of mosquito‐borne pathogens in macaques living in national parks, we aimed to determine the seroprevalence of antibodies to crude salivary gland extracts (SGEs) from culicine mosquitoes (Aedes aegypti [Linnaeus, 1762], Ae. albopictus [Skuse, 1895] and Culex quinquefasciatus [Say, 1823]) and compare individual titres between macaque species/national parks (33, Macaca arctoides [I. Geoffroy Saint‐Hilaire, 1831] [Primates: Cercopithecidae] from Kaeng Krachan, 23 M. leonina leonina [Blyth, 1863] [Primates: Cercopithecidae] from Khao Yai and four M. fascicularis [Raffles, 1821] [Primates: Cercopithecidae] from Mu Ko Ranong). The anti‐mosquito SGE antibodies found in 60 macaques from three national parks indicate varying levels of host‐vector exposure. Macaque antibody titres were high against culicine mosquitoes. However, the significant difference among national parks (or macaque species) was only observed against Cx. quinquefasciatus. Correlation analysis of titres between Aedes SGE and arboviruses revealed a significantly more intense immune response against Ae. albopictus in DENV3‐positive M. arctoides. Current findings support the concept of salivary biomarkers using accessible SGE, available from mosquito colonies of interest. However, we observed cross‐reactivity between Aedes species because of crude SGE containing species‐shared proteins. Nevertheless, a potential risk of pathogen transmission is emphasised between national park visitors and macaques via mosquitoes as bridge vectors. This information contributes to preventive measures against mosquito bites, including those implemented in tourist areas. [ABSTRACT FROM AUTHOR]

Biodiversity is threatened by both climate and land‐use change. However, the synergistic impacts of these stressors and the underlying mechanisms remain poorly understood. This study seeks to bridge this knowledge gap by testing two competing hypotheses regarding the concept of the realized thermal niche. The Fixed Niche Breadth hypothesis suggests that a species' thermal niche remains constant despite fluctuations in population density resulting from land‐use changes. This hypothesis links habitat loss directly to a reduced availability of suitable climate. Conversely, the Habitat Loss‐Allee Effect hypothesis posits that land‐use changes narrow the realized thermal niche by lowering population densities, which impairs individual fitness in unfavorable temperatures due to the Allee effect—the positive impact of higher population density on individual fitness. To investigate these hypotheses, we developed an individual‐based model that integrates the Allee effect to examine how climate and land‐use changes affect population density and the thermal niche in social organisms. We empirically tested our model predictions by studying the distribution and cooperative behavior of burying beetles (Nicrophorus nepalensis), which compete with blowflies for carrion resources, along two elevational gradients in Taiwan. These gradients serve as temperature gradients, one in an intact forest and the other in a human‐altered landscape with substantial forest loss. Our results support the model predictions and show that landscape forest loss reduces beetle population densities and disrupts their dispersal dynamics, resulting in smaller cooperative groups. This, in turn, limits the beetles' ability to compete with blowflies in warmer environments, resulting in a contraction of the realized thermal niche. Together, our findings support the Habitat Loss‐Allee Effect hypothesis while rejecting the Fixed Niche Breadth hypothesis. By highlighting the effects of habitat loss and fragmentation on both intra‐ and interspecific social interactions, our study improves understanding of species' vulnerability to the combined threats of climate and land‐use change. Ultimately, our results underscore the importance of considering the demographic and behavioral consequences of land‐use change when assessing species' vulnerability to climate‐land‐use synergies. [ABSTRACT FROM AUTHOR]

Drug and toxin-related deaths are common worldwide, making it essential to detect the postmortem concentration of various toxic substances at different stages of decomposition in a corpse. Indeed, determining the postmortem interval (PMI) and cause of death in an advanced stage of decomposed corpses has been a significant challenge in forensic investigations. Notably, the presence of drugs or toxins can have a significant impact on the microbial profile, potentially altering the succession of microbial communities and subsequent production of volatile organic compounds (VOCs), which, in turn, affect insect colonization patterns. This review aims to highlight the importance of investigating the interactions between drugs or toxins, microbial succession, VOC profiles, and insect behavior, which can provide valuable insights into forensic investigations as well as the ecological consequences of toxins occurring in decomposition. Overall, the detection of drugs and other toxins at different stages of decomposition can yield more precise forensic evidence, thereby enhancing the accuracy of PMI estimation and determination of the cause of death in decomposed remains. [ABSTRACT FROM AUTHOR]

The role of epigenetics in regulating caste polyphenism in social insects has been debated. Here, we tested the importance of histone de/acetylation processes for the maintenance of queen hallmarks like a high fecundity and a long lifespan. To this end, we performed RNA interference experiments against histone deacetylase 3 (HDAC3) in the termite Cryptotermes secundus. Fat body transcriptomes and chemical communication profiles revealed that silencing of HDAC3 leads to signals indicative of queen hallmarks. This includes fostering of queen signalling, defence against ageing and a reduction of life‐shortening IIS (insulin/insulin‐like growth factor signalling) and endocrine JH (juvenile hormone) signalling via Kr‐h1 (Krüppel‐homologue 1). These observed patterns were similar to those of a protein‐enriched diet, which might imply that histone acetylation conveys nutritional effects. Strikingly, in contrast to solitary insects, reduced endocrine JH signalling had no negative effect on fecundity‐related vitellogenesis in the fat bodies. This suggests an uncoupling of longevity pathways from fecundity in fat bodies, which can help explain queens' extraordinary lifespans combined with high fecundity. [ABSTRACT FROM AUTHOR]

Many seabirds congregate in large colonies for breeding, a time when they are central place foragers. An influential idea in seabird ecology posits that competition during breeding results in an area of reduced prey availability around colonies, a phenomenon known as Ashmole's halo, and that this limits colony size. This idea has gained empirical support, including the finding that species coexisting within a colony might be able to do so by foraging on a single prey species but at different distances. Here, we provide a comprehensive mathematical model for central place foragers exploiting a single prey in a two-dimensional environment, where the prey distribution is the result of intrinsic birth and death, movement in space, and mortality due to foraging birds (we also consider a variant tailored toward colonial social insects). Bird predation at different distances occurs according to an ideal free foraging distribution that maximizes prey delivery under flight and search costs. We fully characterize the birds' ideal free distribution and the prey distribution it generates. Our results show that prey depletion halos around breeding colonies are a robust phenomenon and that the birds' ideal free distribution is sensitive to prey movement. Furthermore, coexistence of several seabird species on a single prey easily emerges through behavioral niche partitioning whenever trait differences between species entail trade-offs between efficiently exploiting a scarce prey close to the colony and a more abundant prey far away. Such behavioral-based coexistence-inducing mechanism should generalize to other habitat and diet choice scenarios. [ABSTRACT FROM AUTHOR]

Caste differentiation involves many functional traits that diverge during larval growth and metamorphosis to produce adults irreversibly adapted to reproductive division of labor. Investigating developmental differentiation is important for general biological understanding and has increasingly been explored for social phenotypes that diverge in parallel from similar genotypes. Here, we use Monomorium pharaonis ants to investigate the extent to which canalized worker development can be shifted toward gyne (virgin-queen) phenotypes by juvenile hormone (JH) treatment. We show that excess JH can activate gyne-biased development in workers so that wing-buds, ocelli, antennal and genital imaginal discs, flight muscles, and gyne-like fat bodies and brains emerge after pupation. However, ovary development remained unresponsive to JH treatment, indicating that JH-sensitive germline sequestration happens well before somatic differentiation. Our findings reveal important qualitative restrictions in the extent to which JH treatment can redirect larval development and that these constraints are independent of body size. Our findings corroborate that JH is a key hormone for inducing caste differentiation but show that this process can be asymmetric for higher colony-level germline versus somatic caste differentiation in superorganisms as defined a century ago by Wheeler. We quantified gene expression changes in response to JH treatment throughout development and identified a set of JH-sensitive genes responsible for the emergence of gyne-like somatic traits. Our study suggests that the gonadotropic role of JH in ovary maturation has shifted from the individual level in solitary insects to the colony level in an evolutionary-derived and highly polygynous superorganism like the pharaoh ant. [ABSTRACT FROM AUTHOR]

Cryptotermes brevis (Walker) (Blattodea: Kalotermitidae) is one of the most destructive drywood termites that attack moisture‐protected timber in service. Heat treatment has been studied to control these termites, but the low thermal conductivity of wood can result in prolonged treatment times and the need for high temperatures to eliminate termite colonies. The current study investigated heat transfer through a heat transfer model and experiments within solid timber boards and a representative wall section. The aim was to optimise targeted spot heat treatment as a cost‐effective method for eradicating this pest within structural elements. Through experimental work and the development of a deterministic heat transfer model, valuable insights were gained into temperature distribution within wooden structural elements. The findings revealed that proximity to the heated surface played a crucial role, with closer distances reaching equilibrium temperatures faster. The heat transfer model, validated against experimental data, accurately predicted temperature distributions within the timber. Termite survival was significantly influenced by heating time and distance from the heated surface when a wall section was heated at 60°C. The mean survival of C. brevis pseudergates kept inside wall studs varied from 30% to 96.7% depending on the distance from the heated surface after 1.5 h of heating, where the temperature ranged from 43°C to 45°C. However, after extending the heating duration to 3 h, the temperature in wall studs was elevated to 51°C, 49°C and 47°C at 22, 40 and 60 mm from the heated stud face, respectively. All C. brevis pseudergates across all distances were killed at a 3‐h duration. This research underscores the importance of understanding temperature distribution in structural wood elements and exposure times when employing heat as a spot treatment for drywood termite control. [ABSTRACT FROM AUTHOR]

Simple Summary: This study investigates the impact of envenomation with snake venom on the decomposition of rabbit carcasses and the subsequent attraction of necrophilous coleopteran beetles, a crucial factor in forensic entomology. The research aimed to assess how venoms from the Egyptian cobra (Naja haje) and the horned viper (Cerastes cerastes) influence decomposition stages and beetle colonization patterns. Results indicated that snake envenomation accelerated the decomposition process, particularly shortening the fresh and bloating stages, and reduced the number of beetles attracted to envenomed carcasses compared to controls. Notably, fewer beetles were associated with N. haje envenomed carcasses. The findings highlight the significant role of snake venom in altering carcass decomposition and insect succession, providing valuable insights for forensic investigations. Understanding these relationships can enhance the accuracy of estimating the postmortem interval in legal cases, ultimately contributing to more effective crime scene analyses and improving public safety through more effective forensic practices. Background: Coleoptera is the second-most significant insect group associated with decomposing carcasses, yet its role in the decomposition process and postmortem colonization following envenomation is poorly understood. Purpose of the Study: This study aimed to investigate the effects of the venoms from Cerastes cerastes and Naja haje on the decomposition of rabbit carcasses while evaluating the main beetle taxa attracted to these decaying remains. Methods: Three groups of rabbits, each with five individuals, were utilized. The first group was injected with the venom of Cerastes cerastes, the second with Naja haje venom, and the control group received 0.85% physiological saline before euthanasia with CO2. Results: Four decomposition stages (fresh, bloating, decay, and dry) with durations varying based on venom type and carcass condition were observed. A total of 647 individual beetles of six species (Necrobia rufipes, Attagenus sp., Dermestes frischii, D. maculatus, Bledius sp., and Apentanodes sp.) belonging to four families (Cleridae, Dermestidae, Staphylinidae, and Tenebrionidae) were collected and identified. D. maculatus was the most abundant species. Fewer beetles were attracted to carcasses envenomed with N. haje compared to the other groups. Conclusions: Envenomation by snake venom influences the attraction and succession rate of necrophilous coleopterans to carcasses, which is important for forensic investigations. [ABSTRACT FROM AUTHOR]

Simple Summary: The yellow-necked dry-wood termite, Kalotermes flavicollis, is a significant pest in wooden structures in Europe, particularly churches and museums. An increase in infestations has been observed in Palermo, Italy, affecting both structural elements and artefacts. A study aimed at gaining further knowledge of this insect permitted the isolation and identification of three fungal species associated with dead termites: Aspergillus nomius, A. subramanianii, and A. tamarii. This is the first report of fungi linked to K. flavicollis and the first recorded association of A. subramanianii with Isoptera (order of social insects that live in colonies, including termites). Further research will be conducted to define the possible ecological relationships between these organisms. The yellow-necked dry-wood termite Kalotermes flavicollis (Fabricius, 1793) (Blattodea: Kalotermitidae) is an important pest that infests wood in Europe. An increase in attacks by K. flavicollis has been seen in buildings and in churches in Palermo (Italy), with attacks on both structural elements and artefacts. Future climate changes are expected to lead to increasing temperatures, which will probably affect the pest status of this species, which is difficult to control. In this context, it is important to identify potential natural antagonists of K. flavicollis. During a survey of the K. flavicollis population, several dead individuals with evident fungal efflorescence were found. Therefore, a study aimed at the isolation and identification of these microorganisms was conducted. Fungal colonies isolated from mycelial structures grown on insects were identified based on morphological characteristics and DNA profiling. Three different species were identified: Aspergillus nomius, A. subramanianii, and A. tamarii. This is the first time that fungi have been recorded in association with the yellow-necked dry-wood termite and, in addition, this study reports the first association of A. subramanianii with Isoptera. [ABSTRACT FROM AUTHOR]

Simple Summary: Interactions betweoen living organisms of different species may be negative or positive for the interaction partners, as these species may hinder or help each other. Plant sap-feeding insects, such as aphids, may indirectly interact with other species feeding on the same plant at the same time by causing changes to the shared host plant and potentially affecting the performance of and the balance between the species. We compared the colony sizes of two species of grain aphids, which were infesting leaves or ears of wheat at the same time. The wheat plants had either been previously infested by one of the two species or kept uninfested, to determine if a previous infestation affects interaction with the other species. Colony sizes of the pre-infesting aphid species were increased on the previously infested plants at some time points. There were only minor changes in the balance of the two species. With the findings derived from this study, we can better understand the interactions between two important cereal pest species. Our findings are important from an agricultural perspective, as wheat is an important crop plant species that may suffer from infestation by different aphid species. Different herbivorous species that share a host plant may interact via competition or facilitation, depending on whether the interaction partners are hindered by or benefit from the interaction. Sap-sucking insects, such as aphids, can influence each other indirectly by altering the composition of the shared phloem sap. Aphid-induced changes in the plant may affect aphid performance and lead to a shift in the balance between different co-occurring aphid species. In this study, we compared the performance of the English grain aphid (Sitobion avenae) and the bird cherry-oat aphid (Rhopalosiphum padi) simultaneously infesting leaves or ears of wheat (Triticum aestivum) plants, which had been either previously infested by S. avenae or kept uninfested. Colonies of S. avenae were larger on ears than on leaves, while the opposite pattern was found for R. padi. Pre-infestation of ears, but not of leaves, by S. avenae led to a higher total aphid number and colony size of S. avenae at some time points. The balance between the two species was only slightly affected by previous infestation at some time points. The findings of this study contribute to the understanding of plant–aphid as well as aphid–aphid interactions in agricultural fields. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa (Xf) bacteria form biofilm on the cuticular surfaces of the functional foregut (precibarium and cibarium) of its vectors, xylem fluid-ingesting sharpshooter leafhoppers and spittlebugs. While much is known about Xf biofilm development and maturation in vitro, little is known about these processes in vectors. Real-time (RT)-PCR was used to quantify Xf genomes daily in the functional foreguts of blue-green sharpshooters, Graphocephala atropunctata, over 7 days of exposure to infected grapevines. Scanning electron microscopy (SEM) was used to examine Xf biofilm formation at 4 and 7 days of that time course. PCR showed populations building and reducing over a 4-day cycle. SEM revealed that foreguts at 4 days showed variability in quantity and location of bacterial attachment. Only early-stage biofilm formation occurred in low-turbulence areas of the cibarium, while high-turbulence areas of the cibarium and precibarium had rare but older, more developed macro-colonies. Biofilm was almost absent at 7 days but left behind adhesive material and remnants of prior colonization. Evidence supports the hypothesis that bacterial colonization was repeatedly interrupted and constrained by the vector. Behaviors such as egestion and enzymatic salivation likely can loosen and eject Xf biofilm, perhaps when profuse biofilm interferes with ingestion. Thus, vector acquisition of Xf is a dynamic and stochastic process of interactions between bacteria and insects. We further hypothesize for future testing that the insect can regulate this interaction. A deep understanding of Xf acquisition will aid the ongoing development of grapevine resistance to vector transmission of xylellae diseases. IMPORTANCE Xylella fastidiosa (Xf) is one of the most destructive invasive plant pathogens in the world, able to hijack new vectors when it invades a region; yet the temporal interplay of bacterial colonization and insect behavior is unknown. This paper describes important findings about the process of Xf biofilm formation and maturation in a vector, contrasting similarities and differences with such formation in vitro. Results support the hypothesis that the behavior of the vector constrains and may regulate Xf biofilm formation, in dynamic competition with the bacterium. The data from this paper partly explain why Xf is so successful at invasion. Because the bacterium can be acquired and inoculated very quickly, it can move readily from old to new vectors and host plants in all-new environments. Our findings are relevant to biosecurity decisions because they demonstrate the importance of identifying potential vector species in the Xylella invasion front. [ABSTRACT FROM AUTHOR]

Scientists have long studied the unexpected resistance of eusocial insect colonies to pathogen and parasitic threats. Despite having many closely related individuals living in proximity, these colonies have shown the ability to persist for long periods of time without epidemic collapse. Previous studies have theorized a variety of reasons for their ability to withstand chronic infections including the conveyor belt model and task specialization. The impact of each of these different strategies and the synergy between them is unknown. Testing the impact of each strategy experimentally may be difficult and time consuming. This paper examines the impact of five (5) strategies used by Camponotus rufipes to endure a chronic infection from Ophiocordyceps camponoti-rufipedis, a fungal infection which results in "zombie ants." These five strategies are to avoid areas with increased numbers of spores, prevent completion of the fungal lifecycle within the nest, use specialized workers, separate groups within the nest, and invest less in forager immune response. A full factorial analysis of the strategies is performed through an agent-based model by selectively turning "off" each of the strategies. The contribution of this work is two-fold. First, a conceptual model for C. rufipes is presented. Synthesizing the current literature, the result is a tool for modeling colony behavior. Secondly, the output of the model indicates the role of each strategy in preventing fungal disease propagation in the colony and the interaction effects between the strategies. Analysis includes a 5-way ANOVA with interaction effects, post-hoc testing, and effect size measurements. Significant findings include that the strategy of minimizing the chance of fungal infection and preventing the fungus from completing its life cycle within the nest are the most important. When these strategies were disabled, 100% of colony collapse occurred. Additionally, the use of the conveyor belt approach (the use of older ants to forage) had a negligible effect on colony survival. Interaction effects between the five strategies are also presented. The results of this work highlight the synergies between the strategies used to prevent O. camponoti-rufipedis propagation, guide future experimentation on this species, and provide additional information for those seeking to use this species as a source of biologically inspired design. [ABSTRACT FROM AUTHOR]

As pollinators, bees are key to maintaining the biodiversity of angiosperm plants, and for agriculture they provide a billion-dollar ecosystem service. But they also compete for resources (primarily nectar and pollen), especially the highly social bees that live in perennial colonies. So, how do they organize their daily temporal activities? Here, we present a versatile, low-cost device for the continuous, automatic recording and data analysis of the locomotor activity in the colony-entrance tube of highly eusocial bees. Consisting of an in-house built block containing an infrared detector, the passage of bees in the colony entrance tunnel is registered and automatically recorded in an Arduino environment, together with concomitant recordings of temperature and relative humidity. With a focus on the highly diverse Neotropical stingless bees (Meliponini), we obtained 10-day consecutive recordings for two colonies each of the species Melipona quadrifasciata and Frieseomelitta varia, and also for the honey bee. The Lomb-Scargle periodogram analysis identified a predominant circadian rhythmicity for all three species, but also indications of ultradian rhythms. For M. quadrifasciata, which is comparable in size to the honey bee, we found evidence for a possibly anticipatory activity already before sunrise. As all three species also presented activity at night in the colony entrance tube, this also raises questions about sleep organization in social insects. The cost and versatility of the device and the open-source options for data analysis make this an attractive system for conducting studies on circadian rhythms in social bees under natural conditions, complementing studies on flower visits by these important pollinators. [ABSTRACT FROM AUTHOR]

Nestmate recognition is a widespread phenomenon and evolutionary important trait in the social insects. Yet evidence accumulates that the responses to non‐nestmates varies more than previously thought. We present a simple frequency‐dependent cost‐benefit model of nestmate recognition to understand conditions that might or might not favor the evolution of nestmate recognition that is based on cuticular hydrocarbon (CHC) profiles. Costs accounted for are costs for 1) maintaining a functional recognition system and 2) keeping a CHC profile that may be sub‐optimal regarding other functionalities like desiccation control, whereas the benefit of recognition is the prevention of nest raiding by other colonies. Unsurprisingly, the model indicates that recognition systems only evolve if costs are sufficiently low and benefits sufficiently high. In addition, the model suggests that nestmate recognition is more likely to evolve if colony turnover is fast (colony life‐expectancy is low). Our model creates evolutionary cycles that are typically longest under parameter combinations that just allow the evolution of recognition systems at all; the system expresses attributes of a rock‐paper‐scissors game. The model shows that a breakdown of nestmate recognition may occur under changing ecological situations, e.g. as a result of reduced intraspecific competition or increased abiotic stress. We speculate that such effects may be involved in the formation of supercolonies during invasions. Nestmate recognition may have evolved more to prevent interspecific predation or parasitism by antagonists that managed to mimic their host's CHC profile than as a mechanism to prevent exploitation by conspecific colonies. [ABSTRACT FROM AUTHOR]

Communication allows members of a collective to share information about their environment. Advanced collective systems, such as multicellular organisms and social insect colonies, vary in whether they use communication at all and, if they do, in what types of signals they use, but the origins of these differences are poorly understood. Here, we develop a theoretical framework to investigate the evolution and diversity of communication strategies under collective-level selection. We find that whether communication can evolve depends on a collective's external environment: communication only evolves in sufficiently stable environments, where the costs of sensing are high enough to disfavour independent sensing but not so high that the optimal strategy is to ignore the environment altogether. Moreover, we find that the evolution of diverse signalling strategies—including those relying on prolonged signalling (e.g. honeybee waggle dance), persistence of signals in the environment (e.g. ant trail pheromones) and brief but frequent communicative interactions (e.g. ant antennal contacts)—can be explained theoretically in terms of the interplay between the demands of the environment and internal constraints on the signal. Altogether, we provide a general framework for comparing communication strategies found in nature and uncover simple ecological principles that may contribute to their diversity. [ABSTRACT FROM AUTHOR]

To understand the mechanisms underlying social evolution and caste development in social insects, caste-specific organs and genes should be investigated. In the rhinotermitid termite, Reticulitermes speratus, the lipocalin gene RS008881, which encodes a protein transporter, is expressed in the ovarian accessory glands of primary queens. To obtain additional data on its expression and product localization, we conducted real-time quantitative polymerase chain reaction and protein assays using a peptide antibody. Gene expression analysis of the castes revealed that RS008881 was highly expressed in female primary and secondary reproductives. Further analysis of its expression during reproductive caste differentiation showed that its expression levels increased prior to molting into reproductive individuals, even during the winged imago (alates) stage. Western blotting and fluorescent immunohistochemical staining revealed that the RS008881 product was localized in the ovary as well as the eggshells produced by female reproductives. RS008881 may play a significant role in the reproductive biology of R. speratus; protein localization in both the ovary and eggshell suggests multiple functions related to embryo protection and potential pheromone interactions. [ABSTRACT FROM AUTHOR]

Many social insect species build nests, which differ from the surrounding environment and are often occupied by specific organismal communities. These organisms may interact mutualistically or parasitically with the nest‐builders, or simply co‐occur, being able to survive in these microenvironments. In temperate forests, red wood ants (e.g. Formica polyctena) are known to create distinct, highly developed nests, which consist of large, above‐ground mounds, built primarily out of plant matter collected from the forest litter. The microorganismal communities of such mounds remain understudied. As representatives of Mucoromycota fungi commonly engage in the decomposition process of the forest litter, they would be expected to occur in the mounds. However, it is still not known whether the Mucoromycota community of these ants' nests differ from the one of the surrounding forest litter. In order to distinguish mound‐associated taxa, we characterized Mucoromycota communities of Formica polyctena mounds and the surrounding forest litter. We sampled four sites, twice in a season. Sampled material was plated on agar media and emerging Mucoromycota colonies were identified based on their morphology. Fungal identification was further confirmed using DNA barcoding. In order to compare described communities, PERMANOVA test and non‐metric multidimensional scaling ordinations were used. To distinguish taxa associated with the mounds, multilevel pattern analysis was performed. Our results show that the Mucoromycota community of Formica polyctena's mound differs from the community of the surrounding forest litter. While representatives of Entomortierella lignicola and Absidia cylindrospora clade were found to be associated with the mound environment, representatives of Umbelopsis curvata and Podila verticillata‐humilis clade were associated with forest litter, and were rarely present in the mounds. Our findings strongly suggest that the red wood ants' nest is a specific microenvironment in the temperate forest floor, which is a preferred microhabitat for the mound‐associated Mucoromycota, possibly adapted to live in proximity to ants. [ABSTRACT FROM AUTHOR]

The niche of aphids is largely defined by their consumption of plant phloem sap and its composition, including nutrients and specialized metabolites. Niche construction is the change of the environment by organisms, which may influence the fitness of these organisms and their offspring. To better understand interactions between plants and aphids, it is necessary to investigate whether aphids modify the chemical composition of the phloem sap of their host plants and whether conspecifics are affected by previous infestation. In the current study, ears of wheat (Triticum aestivum) plants were infested with clonal lineages of the English grain aphid (Sitobion avenae) or were left uninfested. The metabolic composition of ear phloem sap exudates was analyzed through amino acid profiling and metabolic fingerprinting. Aphids of the clonal lineages were either put on previously aphid-infested or on uninfested ears and their colony sizes followed over time. Furthermore, it was investigated whether aphids choose one treatment group over another. Sitobion avenae infestation affected the relative concentrations of some metabolites in the phloem exudates of the ears. Compared to uninfested plants, the relative concentration of asparagine was higher after aphid infestation. Colonies grew significantly larger on previously aphid-infested ears, which the aphids also clearly chose in the choice experiment. The pronounced positive effect of previous infestation on aphid colonies indicates niche construction, while the choice of these constructed niches reveals niche choice by S. avenae on wheat. The interplay between these different niche realization processes highlights the complexity of interactions between aphids and their hosts. [ABSTRACT FROM AUTHOR]

The cultural transmission of behaviour patterns across animal populations and between generations has been rigorously demonstrated in diverse vertebrate species and also in insects, but controversies continue about exactly what distinguishes nonhuman from human cultural learning. A contentious contemporary debate concerns a hypothetical 'zone of latent solutions' (ZLS), conceptualized as all that members of a species can acquire by individual learning. The ZLS hypothesis proposes that cumulative culture is restricted to humans because of a unique ability to copy behavioural innovations beyond our species' ZLS. Apes and other taxa are argued instead to be limited to copying only behaviours that are already within their ZLS, thus constraining their capacity for cumulative culture. Here I suggest that empirical tests of this hypothesis are scattered through the research literature covering social learning experiments and I collate relevant instances. Over 20 such studies spanning mammals, birds, fish and insects demonstrate social learning of novel actions new to the species that no individual acquires through its own efforts. Many offer particularly compelling refutation of the ZLS hypothesis because in addition to documenting an absence of individual level learning, they incorporate designs showing that observers match whichever of two alternative forms of action they witnessed or include multistep actions that are clearly challenging for individuals of the species studied to acquire by individual learning. • A ZLS hypothesis argues only humans socially learn actions beyond individual learning. • Review of past literature yields 26 experiments whose findings counter this. • Studies span apes, other mammals, birds, reptiles and insects. • Ten two-action experiments show copies of either option acquired by observers. • Other studies show copying of difficult multistep actions beyond individual learning. [ABSTRACT FROM AUTHOR]

While terrestrial decomposition has been extensively researched to produce reliable methods of estimating the post-mortem interval of remains, there is limited literature documenting aquatic decomposition. Consequently, the ability to reliably estimate the post-mortem submersion interval for remains in water bodies is poor, despite markedly varying insect succession between aquatic and terrestrial decomposition This study was conducted to compare decomposition on Sus domesticus carcases in terrestrial and artificial lentic environments, aiming to provide more detailed characterization of aquatic decomposition and document the role of terrestrial organisms in the accompanying insect succession. Three trials consisting of six stillborn piglets in lentic environments and three in terrestrial environments were observed daily over a period of 12 months. Decomposition stage and morphological changes between terrestrial and lentic piglets were noted. Insects were sampled from remains and reared to adulthood for identification. Lentic decomposition was prolonged relative to terrestrial decomposition, reflecting aquatic decomposition characteristics accompanied by terrestrial insect colonization. Diptera were more prevalent on terrestrial remains, and Coleoptera in the lentic environments, with few dipteran taxa common between environments. Results show the variability of decomposition stages, characteristics and insects between terrestrial and lentic remains, and are discussed with regard to implications for aquatic forensic casework. [ABSTRACT FROM AUTHOR]

Epigenetic mechanisms, such as DNA methylation, are crucial factors in animal development. In some mammals, almost all DNA methylation is erased during embryo development and re‐established in a sex‐ and cell‐specific manner. This erasure and re‐establishment is thought to primarily be a vertebrate‐specific trait. Insects are particularly interesting in terms of development as many species often undergo remarkable morphological changes en route to maturity, that is, morphogenesis. However, little is known about the role of epigenetic mechanisms in this process across species. We have used whole‐genome bisulfite sequencing to track genome‐wide DNA methylation changes through the development of an economically and environmentally important pollinator species, the bumblebee Bombus terrestris (Hymenoptera:Apidae Linnaeus). We find overall levels of DNA methylation vary throughout development, and we find developmentally relevant differentially methylated genes throughout. Intriguingly, we have identified a depletion of DNA methylation in ovaries/eggs and an enrichment of highly methylated genes in sperm. We suggest this could represent a sex‐specific DNA methylation erasure event. To our knowledge, this is the first suggestion of possible developmental DNA methylation erasure in an insect species. This study lays the required groundwork for functional experimental work to determine if there is a causal nature to the DNA methylation differences identified. Additionally, the application of single‐cell methylation sequencing to this system will enable more accurate identification of if or when DNA methylation is erased during development. [ABSTRACT FROM AUTHOR]

In Indonesia, the control of Coptotermes curvignathus populations as living tree termite pests has been carried out since the early 20th century. Recently, C. curvignathus has been considered the main termite pest and designated as the only species model for wood and wood products resistance tests against subterranean termite attack testing protocol in the Indonesian National Standard (SNI). However, the species distribution range of C. curvignathus has been long questioned as Coptotermes gestroi is commonly reported as a species found in urban areas of Southeast Asian region, particularly in Indonesia. One of the reasons for the species distribution discrepancies is the lack of morphological markers to distinguish both species in the field. Thus, limiting the field inspection effectiveness in termite pest management in Indonesia. This study reexamined and clarified the morphological differences between C. curvignathus and C. gestroi , based on soldier caste. The head shape, mandible shape, and distribution of genal setae on the ventro-anterior head part and pronotum marked the difference between the 2 species. These current results support previous findings of C. curvignathus as the forest dweller while clarifying C. gestroi as the common urban dweller in Indonesia. The putative benefit of morphological features related to the head, mandible, and setae distribution to the defensive adaptation in their common habitat was discussed. Ultimately, the inclusion of C. gestroi into the Indonesian National Standard (SNI) as an alternative species for efficacy tests against subterranean termites is highly recommended. [ABSTRACT FROM AUTHOR]

Social insect pests, particularly leaf-cutting ants, present a considerable challenge in terms of control. Leaf-cutting ants are significant agricultural, forestry, and pasture pests, and understanding their behavior and defense mechanisms is essential for managing their colonies effectively. While toxic ant baits are a primary control method, the limited availability of effective insecticides and concerns over their hazardous nature has spurred the search for alternative solutions, particularly natural compounds, which aligns with the goals of forest certification groups. In the light of previous evidence demonstrating the efficacy of nasturtium leaves (Tropaeolum majus L. (Brassicales: Tropaeolaceae)) in suppressing leaf-cutting ant colonies, this study investigates 2 active components of nasturtium leaf extracts: diphenyl disulfide and lyral. We tested their impact on Atta sexdens (L.) (Hymenoptera: Formicidae), the most prevalent leaf-cutter ant species in Brazil, and their symbiotic fungus, Leucoagaricus gongylophorus (Möller) Singer (Agaricales: Agaricaceae). We conducted experiments with increasing concentrations of diphenyl disulfide and lyral, assessing their effects on the symbiotic fungus and on forager workers and gardeners of A. sexdens colonies. Our findings revealed no fungicidal activity, and ant mortality was minimal in both topical and ingestion bioassays with the exception of gardeners topically exposed to diphenyl sulfide. Furthermore, the compounds did not affect leaf ingestion, but diphenyl disulfide did increase interactions among foragers. These results suggest that neither diphenyl disulfide nor lyral are the primary contributors to the suppression of leaf-cutting ant colonies by nasturtium leaves. However, they may enhance the formicidal activity of other compounds present in nasturtium leaves. [ABSTRACT FROM AUTHOR]

The use of nonrepellent liquid termiticides against subterranean termites has long relied on the assumption that foraging termites in soils could transfer toxicants to nestmates to achieve population control. However, their dose-dependent lethal time can lead to rapid termite mortality in proximity of the treatment, triggering secondary repellency. The current study characterizes the dynamic nature of the "death zone," i.e. the area adjacent to soil termiticides that termites would avoid owing the accumulation of cadavers. Using whole subterranean termite laboratory colonies of Coptotermes gestroi (Wasmann) with 3 × 15 m foraging distances, fipronil was implemented at 1.5 m, 7.5 m, or 12.5 m away from colony central nests, emulating a corrective action against an termite structural infestation. For treatments at 7.5 m and 12.5 m, the death zone stabilized at an average of ~2.56 m away from the treatment after 40 d post-treatment, and colonies suffered as little as 1.5% mortality by 200 d post-treatment. Colonies located 1.5 m away from the treatment minimized the death zone to ~1.1 m and suffered as little as 23.5% mortality. Mortality only occurred within the first few days of treatment from initial exposure, as the rapid emergence of the death zone negated further transfer effects among nestmates over time. In some cases, foraging termites were trapped within the infested structure. While technically nonrepellent, fipronil becomes functionally repellent from the rapid mortality onset near the treatment. Even if diligently implemented to successfully protect structures, surrounding termite colonies are minimally impacted by fipronil soil treatments. [ABSTRACT FROM AUTHOR]

Males are a ubiquitous feature of animals and play crucial roles beyond the contribution of gametes in some species (e.g., paternal care for offspring and nuptial gifts for females). In termites, colonies commonly consist of both male and female reproductives, workers, and soldiers (i.e., mixed‐sex societies), where males and females both play critical roles beyond reproduction (e.g., brood care, foraging, nest construction and maintenance, and colony defense). Male‐specific roles may also exist in termite colonies. While obligate asexuality had not been observed in any termite population until recently, all‐female asexual populations of the termite Glyptotermes nakajimai were reported in 2018. This was the first and only known case of evolutionary transition from mixed‐sex to all‐female asexual societies in animals. Here, asexual reproduction in termites is first reviewed, followed by a discussion of how and why G. nakajimai evolved obligate asexuality. The study of the evolution of obligate asexuality in termites with mixed‐sex societies is important because it may enhance our understanding of the significance of males in animal societies and populations. [ABSTRACT FROM AUTHOR]

Social insects, particularly honey bees, have exceptionally high genomic frequencies of genetic recombination. This phenomenon and underlying mechanisms are poorly understood. To characterise the patterns of crossovers and gene conversion in the honey bee genome, a recombination map of 187 honey bee brothers was generated by whole‐genome resequencing. Recombination events were heterogeneously distributed without many true hotspots. The tract lengths between phase shifts were bimodally distributed, indicating distinct crossover and gene conversion events. While crossovers predominantly occurred in G/C‐rich regions and seemed to cause G/C enrichment, the gene conversions were found predominantly in A/T‐rich regions. The nucleotide composition of sequences involved in gene conversions that were associated with or distant from crossovers corresponded to the differences between crossovers and gene conversions. These combined results suggest two types of DNA double‐strand break repair during honey bee meiosis: non‐canonical homologous recombination, leading to gene conversion and A/T enrichment of the genome, and the canonical homologous recombination based on completed double Holliday Junctions, which can result in gene conversion or crossover and is associated with G/C bias. This G/C bias may be selected for to balance the A/T‐rich base composition of eusocial hymenopteran genomes. The lack of evidence for a preference of the canonical homologous recombination for double‐strand break repair suggests that the high genomic recombination rate of honey bees is mainly the consequence of a high rate of double‐strand breaks, which could in turn result from the life history of honey bees and their A/T‐rich genome. [ABSTRACT FROM AUTHOR]

We describe the predatory interactions between Neivamyrmex texanus (Watkins 1972) and the fungal-farming ant Trachymyrmex septentrionalis (McCook 1881) in central Texas and between Nomamyrmex esenbeckii (Westwood 1842) and its numerous species of prey, including the leaf-cutter ant Atta texana (Buckley 1860), in southern Texas. Species of the genus Neivamyrmex are generalist social insect predators that attack termites and a wide variety of species of ants, whereas Nomamyrmex are well-known specialists that evolved heavy body armor and fierce column raiding that is crucial for predation on the well-defended nests of the leaf-cutting ants in the genera Atta and Acromyrmex. We observed a marked difference in the response to the predation by army ants between the raids by Neivamyrmex on T. septentrionalis compared to those by Nomamyrmex on the colonies of A. texana. Our observations suggest that there are two distinct defense adaptations to the army ants. They include either making a stand and fighting, or absconding with the brood and garden, or so-called flight. [ABSTRACT FROM AUTHOR]

The ambrosia beetles Xylosandrus germanus (Blanford) and Xylosandrus crassiusculus (Motschulsky) are nonnative pests in orchards and nurseries in North America. They construct galleries in the sapwood of stressed woody hosts and culture a symbiotic fungus as food for their offspring. Preventing attacks is preferred but a better understanding of their biology may elucidate additional avenues for control. Recent phenological studies are lacking for X. germanus that is common in New York, and biological information on brood and gallery development is lacking for the less abundant X. crassiusculus. We conducted both outdoor rearing and laboratory studies to better understand the timing of key events in the maturation of their galleries, particularly associated with the symbiotic fungi. Two and a partial third summer generation were consistently observed over 2 yr for X. germanus ; and thus, 3 flights of adult females (foundresses) occurred each summer from mid-April to late September. In both the field and laboratory, initial growth of the symbiotic fungus occurs within a few days of gallery initiation. The rapid development of the reproductive tract and oviposition by X. germanus appears to be stimulated by the presence of the fungus. Fungal, reproductive, and brood development are similar for the related X. crassiusculus in laboratory studies; the 2 species mainly appear to differ in size. The lag between beetle colonization and reproduction currently seems too brief to be exploited for management. Disruption of other stages in gallery development should also be explored to minimize the beetle damage if attacks cannot be prevented. [ABSTRACT FROM AUTHOR]

Same-sex sexual behavior (SSB) is an enigma in behavioral ecology as it does not result in reproduction. Proximately, the effect of sexual signals on SSB could be distinct between signal receivers and senders. For receivers, the absence of sexual signals leads to smaller phenotypic sex differences, leading to frequent accidental SSB between receivers. Alternatively, for senders, sexual signals could help locate another sender, enhancing intentional SSB. Here, we demonstrate this link between sex pheromone signaling and the frequency of same-sex pairing in two Coptotermes termites that use the same chemical as sex pheromones but in different quantities. In termites, mating pairs engage in tandem runs, where a female emits sex pheromones to guide a male as they move together in searching a potential nest site. So, females are signal senders, and males are signal receivers for sexual communication. We found that female-female tandems were more stable in C. formosanus, whose females produce more pheromones. On the other hand, although both species did not show stable male–male tandems, males of C. gestroi , whose females produce fewer pheromones, spent more time attempting to follow another male. Thus, stronger pheromones lead to sender–sender SSB, while weaker pheromones lead to receiver–receiver SSB. The proximate mechanism of SSB is diverse according to the properties of sexual communications in heterosexual contexts. [ABSTRACT FROM AUTHOR]

Caste plasticity is an essential trait in social insects, and it facilitates the allocation of individuals in different tasks according to population demands in the colony (e.g. workers can become queens upon loss or death of their "original queen"). The process of caste determination can take place in immature stages (preimaginal) or through adult stages (imaginal). Neotropical social wasp tribe Epiponini has both types of caste determination process and is thus a fascinating group to study caste plasticity. We performed queen removal tests in five Epiponini species with preimaginal and imaginal caste determination to better understand caste plasticity and queen selection processes. Queen absence stimulates the establishment of new reproductive females in Chartergellus and Metapolybia (imaginal), while females in Protopolybia (preimaginal) attempt to lay eggs even in the presence of their "original queen". Contrary to what has been hypothesized, we found that age is not a predictive factor in the female's potential to become a queen. Caste flexibility seems to be a crucial trait which aids Epiponini tropical colonies to survive, as it allows the colony to replace lost workers and queens promptly until a new generation of wasps can emerge. Highlights: Epiponini wasps presented caste flexibility since workers of different ages could replace queens in the case of they lost. [ABSTRACT FROM AUTHOR]

Simple Summary: Bumblebees are important pollinators of both natural and agricultural ecosystems. The quality of their colonies is highly dependent on the reproductive success of the queens and males. This process can be influenced by numerous factors, both positive and negative, some of which directly affect reproductive processes. In this paper, we review current studies on environmental and biological factors that directly affect bumblebee reproduction, including floral resources, pathogens, pesticides, worker behavior, species competition, and hormonal and genetic influences. More studies, particularly those focusing on bumblebees themselves, are needed to understand the effects of these factors and other potential elements. This understanding is essential in order to meet the demands of agricultural pollination and address the decline in wild bee pollinators worldwide. Bumblebees are primary social insects and a vital class of pollinating insects. Their distinctive reproductive mode is characterized by the independent initiation and construction of the nest by the queen and the subsequent production of sufficient workers, males, and gynes following colony development. After successful mating, the queen transitions to the first phase of its annual life cycle. The reproductive processes are directly influenced by environmental factors, including floral resources and pesticides. Moreover, the reproductive level is regulated by biological factors, particularly the role of workers, who participate in egg laying and pass on their genetic material to the next generation of queens. Successful reproduction can only be achieved by maintaining colony development under natural or artificial breeding conditions. Consequently, understanding the known factors that influence bumblebee reproduction is essential for developing conservation strategies for wild bumblebees and for successfully breeding diverse bumblebee species. Breeding various bumblebee species is crucial for in-depth research into known factors and for further exploration of other potential factors, which will also help to meet the demand for pollination in agricultural facilities globally. [ABSTRACT FROM AUTHOR]

Cooperation in social animals can lead to collective disease protection beyond individual-level defences, termed 'social immunity.' Social immunity is unconditionally expressed in superorganismal insect colonies with reproductive division of labour between queens and workers. Being obligate altruists, nonreproductive workers fully commit to colony-level disease defence, exhibiting highly specialised and self-sacrificial behaviours. In families of cooperative breeders, all members can reproduce, but offspring delay reproduction to help parents. Here, cooperation, and thus social immunity, is condition-dependent and likely favoured only by high relatedness and low probability of independent reproduction. Inclusive fitness theory is a useful framework to elucidate the relative importance of direct fitness costs of social immunity against indirect fitness benefits of promoting kin health. Socially living animals can counteract disease through cooperative defences, leading to social immunity that collectively exceeds the sum of individual defences. In superorganismal colonies of social insects with permanent caste separation between reproductive queen(s) and nonreproducing workers, workers are obligate altruists and thus engage in unconditional social immunity, including highly specialised and self-sacrificial hygiene behaviours. Contrastingly, cooperation is facultative in cooperatively breeding families, where all members are reproductively totipotent but offspring transiently forgo reproduction to help their parents rear more siblings. Here, helpers should either express condition-dependent social immunity or disperse to pursue independent reproduction. We advocate inclusive fitness theory as a framework to predict when and how indirect fitness gains may outweigh direct fitness costs, thus favouring conditional social immunity. [ABSTRACT FROM AUTHOR]

The study of social parasitism faces numerous challenges arising from the intricate and intranidal host–parasite interactions and the rarity of parasites compared to their free-living counterparts. As a result, our understanding of the ecology and evolution of most social parasites remains limited. Using whole-genome and reduced-representation sequence data, we conducted a study to fill knowledge gaps on host use, colony social structure, and population genetics of the facultative dulotic ant Formica aserva Forel. Our study reveals the remarkable ability of F. aserva to exploit at least 20 different host species across its wide geographic distribution. In some cases, one social parasite colony exploits multiple hosts simultaneously, suggesting a high degree of generalization even at a local spatial scale. Approximately 80% of the colonies were monogyne (with a single queen), with many exhibiting higher rates of polyandry compared to most Formica ants. Although we identified a supergene on chromosome 3, its association with colony structure remains uncertain due to the rarity of polygyny in our sample. Population genetic analyses reveal substantial geographic population structure, with the greatest divergence between California populations and those from the rest of the range. Mitochondrial population structure differs from structure inferred from the nuclear genome on a broad geographic scale, suggesting a possible role of adaptive introgression or genetic drift. This study provides valuable insights into the ecology and evolution of F. aserva , underscoring the need for further research to decipher the complexities of host interactions and the genetic mechanisms that regulate social structure. [ABSTRACT FROM AUTHOR]

Increasing the resilience of modern infrastructure systems is recognized as a priority by both the International Council on Systems Engineering and the National Academy of Engineering. Resilience answers the key stakeholder need for a stable and predictable system by withstanding, adapting to, and recovering from unexpected faults. Increasing resilience in multi‐agent systems is especially challenging because resilience is an emergent system‐level property rather than the sum of individual agent functions. This paper uses biological systems as a source of inspiration for resilient functions, examining the central question How can biologically inspired design be used to increase the emergent property of resilience in multi‐agent systems? The paper uses functional decomposition to break down the individual functions that result in resilience and transfer the properties to generalized systems. Accordingly, the central hypothesis examined in this article is If functional decomposition is performed on eusocial insect colonies, then generalizable approaches to increase the emergent property of multi‐agent system resilience can be identified. The results provide two contributions. The first contribution is the identification of six general functions based on eusocial insect behavior that influence resilience. The second contribution is a description of the process of identifying and transferring insect behaviors into generalized design‐for‐resilience guidance. To support these contributions, a case study applies biologically inspired functions to an emergency power service system and proposes tactics for the power system to improve its resilience. Thus, this article provides a key step towards our goal of using biologically inspired design to influence the emergent property of resilience in multi‐agent systems. [ABSTRACT FROM AUTHOR]

Social insects have developed a broad diversity of nesting and foraging strategies. One of these, inquilinism, occurs when one species (the inquiline) inhabits the nest built and occupied by another species (the host). Obligatory inquilines must overcome strong constraints upon colony foundation and development, due to limited availability of host colonies. To reveal how inquilinism shapes reproductive strategies in a termite host‐inquiline dyad, we carried out a microsatellite marker study on Inquilinitermes inquilinus and its host Constrictotermes cavifrons. The proportion of simple, extended and mixed families was recorded in both species, as well as the presence of neotenics, parthenogenesis and multiple foundations. Most host colonies (95%) were simple families and all were monodomous. By contrast, the inquiline showed a higher proportion of extended (30%) and mixed (5%) families, and frequent neotenics (in 25% of the nests). This results from the simultaneous foundation in host nests of numerous incipient colonies, which, as they grow, may compete, fight, or merge. We also documented the use of parthenogenesis by female–female pairs. In conclusion, the classical monogamous colony pattern of the host species suggests uneventful development of simple foundations dispersed in the environment, in accordance with the wide distribution of their resources. By contrast, the multiple reproductive patterns displayed by the inquiline species reveal strong constraints on foundation sites: founders first concentrate into host nests, then must attempt to outcompete or absorb the neighbouring foundations to gain full control of the resources provided by the host nest. [ABSTRACT FROM AUTHOR]

Defence mechanisms in plants have been naturally or artificially selected to cope with virus infection and/or insect colonization. This creates a range of host susceptibility to viruses and/or insects that can impact the epidemiology of insect‐borne viral diseases. Wheat dwarf disease (WDD), one of the most important viral diseases on small‐grain cereals, is caused by wheat dwarf virus (WDV), which is transmitted by the leafhopper Psammotettix alienus. In the current context of the unavailability of either WDV‐resistant/tolerant wheat cultivars or effective methods to control WDD in French cereal fields, the accurate characterization of WDV‐susceptible genotypes must be considered to improve management strategies against this viral disease. In this study, the impact of 12 wheat cultivars on epidemiological parameters related to the introduction (host selection and virus infection) and spread (insect performance and virus transmission) of WDD was evaluated. Results showed no differences between the tested cultivars for host selection made by P. alienus, whereas four tested cultivars (Complice, Filon, Hyking and Nemo) reduced survival and/or fecundity of the leafhopper. Characterization of virus–host interactions highlights the lower host and source quality of cv. Filon for WDV. Finally, multivariate analyses allowed the identification of cvs Filon, Boregar, Solindo CS, Complice and Hyking as less suitable hosts for WDV and/or P. alienus, suggesting that these cultivars could present interesting genetic resource(s) that should be considered for future breeding programmes against WDD. [ABSTRACT FROM AUTHOR]

[Display omitted] • Investigates the impact of clonazepam on Megaselia scalaris larval development for PMI estimation. • Utilizes the S9 fraction to assess the effect on larval growth of Phase I and II metabolites. • Megaselia scalaris larvae exposed to clonazepam show accelerated development. • Findings suggest potential accuracy implications for PMI estimation in forensic cases. Fly colonization patterns and development are crucial in estimating the post-mortem interval (PMI) of decomposing corpses. Understanding the potential effects of xenobiotics on species development in cadaveric entomofauna is essential for accurate PMI estimation, given their presence in decomposing bodies. Benzodiazepines, commonly prescribed for their anxiolytic, hypnotic, and muscle relaxant effects, are of forensic interest due to their potential for abuse, dependence, intoxication, and overdose-related deaths. This study aimed to explore the effect of clonazepam and its metabolites on Megaselia scalaris , a species commonly used to estimate PMI, the alteration of which could impact the accuracy of said estimation. The S9 biotransformation fraction, an in vitro model consisting of an array of metabolic enzymes, was used to generate phase I and II metabolites for evaluating their effect on M. scalaris development, representing an innovative approach to this type of study. Megaselia scalaris larvae were reared in synthetic growth media under controlled conditions. The study compared different groups: control, clonazepam, and clonazepam with S9 fraction. Larvae were measured daily to determine growth rate, and clonazepam concentrations were analyzed using HPLC-DAD. Results showed that larvae grown in media containing clonazepam or clonazepam with S9 fraction developed faster than control larvae, reaching their pupal stage earlier. Growth rates were also altered in treated groups. In conclusion, the presence of clonazepam and its metabolites accelerated the life cycle of M. scalaris , potentially impacting the accuracy of PMI estimation. These findings underscore the importance of considering xenobiotics in forensic entomological studies for precise post-mortem interval determination. [ABSTRACT FROM AUTHOR]

Featured Application: Traffic light scheduling optimisation using a task allocation model based on division-of-labour behaviour as observed in insect colonies. Traffic light scheduling is a critical aspect of traffic management with many recently developed solutions that incorporate computational intelligence approaches. This paper presents a traffic light scheduling algorithm based on a task allocation model that simulates the division of labour among insects in a colony, specifically ant colonies. The developed algorithm switches the green light based on a probability calculated every second from the traffic volume around the traffic light. The application of this algorithm to several benchmark simulated traffic scenarios shows optimal performance compared to five other traffic scheduling algorithms. [ABSTRACT FROM AUTHOR]

Pollinators seek high quality nectar and pollen rewards critical for their growth and reproduction. Volatile emissions from inflorescences may signal plant health and floral resource quality to these flower-visiting insects. To understand the relationship between floral volatile emission and pollinator preference in a field setting, we conducted a replicated garden experiment consisting of 18 native perennial species from three different plant families with varying nutritional resource quality. We collected flower-visiting insects and floral volatile emissions over two field seasons, detecting over 60 volatile compounds and over 150 insect species. We collated trait data of visiting insects (bee or non-bee, body size, degree of sociality, nesting behavior, and whether the visitor was non-native) and evaluated interactions between these traits and volatile composition. Among the insect traits, bees and larger visitors had negative associations with sesquiterpenes, while in contrast visitors with complex nesting behaviors and social insects had positive associations. When comparing plant traits with bee traits, bee visitors had negative associations with purple inflorescences and larger insects and social insects both had positive associations with yellow inflorescences. We tested for direct associations between volatile class and insect taxa and found that sesquiterpenes had a strong positive relationship with hoverfly presence. This work demonstrates the complexity of floral volatiles as signals for pollinating insects and how floral scent composition allows individual compounds to act synergistically or antagonistically. These results can help us to better understand pollinator preferences and visitation patterns in the broad context of chemical ecology. [ABSTRACT FROM AUTHOR]

Eusocial organisms typically live in colonies with one reproductive queen supported by thousands of sterile workers. It is widely believed that monogamous mating is a precondition for the evolution of eusociality. Here, we present a theoretical model that simulates a realistic scenario for the evolution of eusociality. In the model, mothers can evolve control over resource allocation to offspring, affecting offspring's body size. The offspring can evolve body-size-dependent dispersal, by which they disperse to breed or stay at the nest as helpers. We demonstrate that eusociality can evolve even if mothers are not strictly monogamous, provided that they can constrain their offspring's reproduction through manipulation. We also observe the evolution of social polymorphism with small individuals that help and larger individuals that disperse to breed. Our model unifies the traditional kin selection and maternal manipulation explanations for the evolution of eusociality and demonstrates that--contrary to current consensus belief--eusociality can evolve despite highly promiscuous mating. [ABSTRACT FROM AUTHOR]

In the Bonabeau model, chemotaxis, which is observed in social insects, such as ants, was introduced into the movement rules of agents to control the collision frequency between agents, and its effect on the mechanism of hierarchical structure formation was investigated. Like an ant, this chemotactic agent makes stochastic decisions regarding its direction of movement depending on the intensity of its released chemicals. Because of this mechanism, the agent depends on its past location history. It can perform different motions from a random walk (RW) and asymmetric attractive or repulsive interactions with other agents via the diffusion of chemotactic substances. When there is an attractive interaction between these agents, they are more likely to aggregate, which increases the effective density; thus, the disparity in the agent winning ratio is more likely to form than in a conventional model with a RW. However, in the case of repulsive interactions, the agents became more distant from each other, the effective density decreased, and a disparity in the winning ratio was less likely to form. This indicates that the disparity in the winning ratio is tunable owing to the interactions between the introduced chemotactic agents. [ABSTRACT FROM AUTHOR]

Eusocial insects, such as ants and termites, are characterized by high levels of coordinated social organization. This is contrasted by solitary insects that display more limited forms of collective behavior. It has been hypothesized that this gradient in sociobehavioral sophistication is positively correlated with chemical profile complexity, due to a potentially increased demand for diversity in chemical communication mechanisms in insects with higher levels of social complexity. However, this claim has rarely been assessed empirically. Here, we compare different levels of chemical and transcriptomic complexity in selected species of the order Blattodea that represent different levels of social organization, from solitary to eusocial. We primarily focus on cuticular hydrocarbon (CHC) complexity, since it has repeatedly been demonstrated that CHCs are key signaling molecules conveying a wide variety of chemical information in solitary as well as eusocial insects. We assessed CHC complexity and divergence between our studied taxa of different social complexity levels as well as the differentiation of their respective repertoires of CHC biosynthesis gene transcripts. Surprisingly, we did not find any consistent pattern of chemical complexity correlating with social complexity, nor did the overall chemical divergence or transcriptomic repertoire of CHC biosynthesis genes reflect on the levels of social organization. Our results challenge the assumption that increasing social complexity is generally reflected in more complex chemical profiles and point toward the need for a more cautious and differentiated view on correlating complexity on a chemical, genetic, and social level. [ABSTRACT FROM AUTHOR]

Social insects have developed different nest defence strategies; for example, social wasps use nonaggressive mechanisms or aggressiveness, including stinging. This subject has been widely examined in the literature, and it may help improve our understanding of wasps' ecology. The nesting behaviour of some genera is still poorly known. In this paper, we report new information on the nesting behaviour of the species Clypearia in different Brazilian biomes. We observed six nesting events in natural and anthropic environments of the Amazon rainforest, Atlantic forest, and Cerrado domains, sporadically from 2004 to 2022. From our observations, we suggest that Clypearia nest defence includes (i) preference for nest camouflage rather than aggressive behaviour; (ii) selection of nesting sites close to water sources in natural or anthropic environments, and eventually obtaining food from the substrate; (iii) nesting association with ants for mutual protection against predators; and (iv) variations in the nests' height. Our records suggest nest camouflage and association with ants are strategies for nest defence. These may have influenced nest height in relation to the ground, which may also vary according to the environment explored by the species. [ABSTRACT FROM AUTHOR]