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Adult wasps primary food resource is larval saliva. This liquid secretion consists mainly of amino acids and carbohydrates processed from the prey brought to the colony by the foragers. However, adults also regularly consume floral nectar. The nectar's most abundant proteinogenic amino acid is proline, and the two most abundant non-proteinogenic amino acids are β-alanine and GABA. These three amino acids are also common in larval saliva. Here, we study the effect of these dietary amino acids on the physiology and nest construction behavior of the Oriental hornet. Our results reveal their deleterious effects, especially at high concentrations: β-alanine and GABA consumption reduced the hornets' lifespan and completely inhibited their construction behavior; while proline induced a similar but more moderate effect. At low concentrations, these amino acids had no effect on hornet survival but did slow down the nest construction process. Using carbon isotopically labeled amino acids, we show that, unlike proline, β-alanine is stored in most body tissues (brain, muscles, and fat body), suggesting that it is rapidly metabolized after consumption. Our findings demonstrate how a single amino acid can impact the fitness of a nectarivore insect.

Reduced human mobility during the pandemic will reveal critical aspects of our impact on animals, providing important guidance on how best to share space on this crowded planet.

Division of labor is central to the ecological success of social insects. Among foragers of the honey bee, specialization for collecting nectar or pollen correlates with their sensitivity to sucrose. So far, differences in gustatory perception have been mostly studied in bees returning to the hive, but not during foraging. Here, we showed that the phase of the foraging visit (i.e. beginning or end) interacts with foraging specialization (i.e. predisposition to collect pollen or nectar) to modulate sucrose and pollen sensitivity in foragers. In concordance with previous studies, pollen foragers presented higher sucrose responsiveness than nectar foragers at the end of the foraging visit. On the contrary, pollen foragers were less responsive than nectar foragers at the beginning of the visit. Consistently, free-flying foragers accepted less concentrated sucrose solution during pollen gathering than immediately after entering the hive. Pollen perception also changes throughout foraging, as pollen foragers captured at the beginning of the visit learned and retained memories better when they were conditioned with pollen + sucrose as reward than when we used sucrose alone. Altogether, our results support the idea that changes in foragers' perception throughout the foraging visit contributes to task specialization.

Increasing temperature beyond a species’ optimum is a major threat to insect biodiversity, particularly in rapidly warming regions such as the Arctic. For cold-adapted pollinators, high temperatures can disrupt physiology and ecosystem services, threatening pollinator populations and plant reproduction. In bumblebees, increased temperature disrupts the physiology of the indirect flight muscles. However, these muscles, which generate the bee’s charismatic buzz, also facilitate key non-flight behaviours including communication, defence, and buzz-pollination, where temperature effects remain unexplored. Here, we assess the thermal performance of non-flight muscle function across 15 Arctic bumblebee species by measuring thorax vibrations during defensive buzzing behaviour. Thorax acceleration is found to peak at an air temperature of 25 °C, declining after this peak as a potential strategy to prevent overheating. Conversely, vibration frequency continues to increase with temperature, and is better explained by thorax temperature than air temperature. Surprisingly, there are no differences in thermal response across species, castes, or temperature habitat specialisations, indicating that non-flight vibrations are similarly susceptible to unfavourable temperatures across bumblebee species. If such findings translate to non-flight buzzing in other contexts, such as buzz-pollination, changes in buzzes have the potential to disrupt key plant-pollinator interactions. Increasing temperatures threaten cold-adapted pollinators such as Arctic bumblebees by disrupting their physiology. This study found that thorax acceleration during non-flight vibrations peaks at 25 °C for these bumblebees, while vibration frequency continues to increase with temperature.

Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees ( Apis mellifera ), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeepers and 165 meliponiculturists participated in the 2-year survey (2016–2017 and 2017–2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost per year across the region. Summer losses were higher than winter losses in stingless bees (30.9% and 22.2%, respectively) but not in honey bees (18.8% and 20.6%, respectively). Colony loss increased with operation size during the summer in both honey bees and stingless bees and decreased with operation size during the winter in stingless bees. Furthermore, losses differed significantly between countries and across years for both beekeepers and meliponiculturists. Overall, winter losses of honey bee colonies in Latin America (20.6%) position this region between Europe (12.5%) and the United States (40.4%). These results highlight the magnitude of bee colony losses occurring in the region and suggest difficulties in maintaining overall colony health and economic survival for beekeepers and meliponiculturists.

Probiotic supplements have the potential to improve the gut flora and enhance nutritional efficacy and blood indices. In this study, sunflower seed meal based diet (SFM) supplemented with a commercial probiotic (protexin ® ) was examined to evaluate the effects on the survival, growth, digestibility, antioxidant status, carcass and hematology of Cirrhinus mrigala fingerlings. Fish were subjected to a 12-week feeding regimen to examine the efficacy of probiotics. Seven diets with different probiotic doses (0, 0.5, 1, 1.5, 2, 2.5, and 3 g kg −1 ) were prepared and randomly assigned to 21 tanks, each stocked with 15 fingerlings, resulting in a total of 315 fish utilized forthe experiment. Analysis showed that fish treated 2 g kg −1 probiotics level exhibited a remarkable 100% survival rate. The results indicated that probiotics (2 g kg −1 ) supplementation revealed notable differences in weight gain (19.76 g), weight gain% (283.15%), FCR (1.31) and SGR (1.49% d −1 ) than other probiotic concentrations and control. The dietary administration of 2 g kg −1 probiotics to C. mrigala resulted in significant improvements in digestibility, with values of 70.52% for protein, 70.30% for gross energy, and 73.71% for fat. Carcass composition also showed notable enhancements, with fat, ash, protein, and moisture content of 4.78%, 2.03%, 18.08%, and 75.11%, respectively. Overall findings indicated that adding 2 g kg⁻¹ probiotics showed improved hematological indices, such as increased red blood cell, hemoglobin and white blood cell count and enhanced antioxidant enzyme activity. Mineral analysis revealed optimal levels at 2 g kg −1 probiotics: Ca (72.57%), Na (73.08%), K (71.45%), P (74.70%), Fe (67.43%), Cu (63.62%), Mg (61.98%), and Al (62.18%). To sum up, the dose of 2 g kg −1 probiotics supplementation has a profoundly positive impact on growth, digestibility, health, and hematology in C. mrigala .

Fish exhibit complex social behaviours that can influence their stress levels and well-being. However, little is known about the link between social interactions and stress in wild fish, especially in running water environments. While many studies have explored the stress axis in fish, most have focused on specific social contexts, leaving gaps in understanding stress responses to social changes. Our study investigated collective behaviour and stress in wild Italian riffle dace ( Telestes muticellus ) in a controlled experimental setup simulating a natural river system. Results reveal that group-living fish have lower cortisol and oxidative stress levels in muscle tissue compared to solitary counterparts, suggesting a calming effect of conspecific presence. Additionally, we observed upregulated expression of antioxidant enzymes in group-living fish, indicating potential benefits to antioxidant defence systems. These insights shed light on the dynamic relationship between group behaviour and stress in wild fish within running water habitats and emphasise the use of multidisciplinary approaches.

Researcher and prolific science communicator who laid bare the social lives of apes. Researcher and prolific science communicator who laid bare the social lives of apes. Frans de Waal poses for a portrait next to some primates in an enclosure

The foraging activity of diurnal bees often relies on flower availability, light intensity and temperature. We do not know how nocturnal bees, which fly at night and twilight, cope with these factors, especially as light levels vary considerably from night to day and from night to night due to moon phase and cloud cover. Given that bee apposition compound eyes function at their limits in dim light, we expect a strong dependence of foraging activity on light intensity in nocturnal bees. Besides being limited by minimum light levels to forage, nocturnal bees should also avoid foraging at brighter intensities, which bring increased competition with other bees. We investigated how five factors (light intensity, flower availability, temperature, humidity, and wind) affect flower visitation by Neotropical nocturnal bees in cambuci ( Campomanesia phaea , Myrtaceae). We counted visits per minute over 30 nights in 33 cambuci trees. Light intensity was the main variable explaining flower visitation of nocturnal bees, which peaked at intermediate light levels occurring 25 min before sunrise. The minimum light intensity threshold to visit flowers was 0.00024 cd/m 2 . Our results highlight the dependence of these nocturnal insects on adequate light levels to explore resources.

Sleep plays an essential role in both neural and energetic homeostasis of animals. Honey bees ( Apis mellifera ) manifest the sleep state as a reduction in muscle tone and antennal movements, which is susceptible to physical or chemical disturbances. This social insect is one of the most important pollinators in agricultural ecosystems, being exposed to a great variety of agrochemicals, which might affect its sleep behaviour. The intake of glyphosate (GLY), the herbicide most widely used worldwide, impairs learning, gustatory responsiveness and navigation in honey bees. In general, these cognitive abilities are linked with the amount and quality of sleep. Furthermore, it has been reported that animals exposed to sleep disturbances show impairments in both metabolism and memory consolidation. Consequently, we assessed the sleep pattern of bees fed with a sugar solution containing GLY (0, 25, 50 and 100 ng) by quantifying their antennal activity during the scotophase. We found that the ingestion of 50 ng of GLY decreased both antennal activity and sleep bout frequency. This sleep deepening after GLY intake could be explained as a consequence of the regenerative function of sleep and the metabolic stress induced by the herbicide.