Heatwave-like events affect drone production and brood-care behaviour in bumblebees.

Climate change is currently considered one of the major threats to biodiversity and is associated with an increase in the frequency and intensity of extreme weather events, such as heatwaves. Heatwaves create acutely stressful conditions that may lead to disruption in the performance and survival of ecologically and economically important organisms, such as insect pollinators. In this study, we investigated the impact of simulated heatwaves on the performance of queenless microcolonies of Bombus terrestris audax under laboratory conditions. Our results indicate that heatwaves can have significant impacts on bumblebee performance. However, contrary to our expectations, exposure to heatwaves did not affect survival. Exposure to a mild 5-day heatwave (30-32 °C) resulted in increased offspring production compared to those exposed to an extreme heatwave (34-36 °C) and to the control group (24 °C). We also found that brood-care behaviours were impacted by the magnitude of the heatwave. Wing fanning occurred occasionally at temperatures of 30-32 °C, whereas at 34-36 °C the proportion of workers engaged in this thermoregulatory behaviour increased significantly. Our results provide insights into the effects of heatwaves on bumblebee colony performance and underscore the use of microcolonies as a valuable tool for studying the effects of extreme weather events. Future research, especially field-based studies replicating natural foraging conditions, is crucial to complement laboratory-based studies to comprehend how heatwaves compromise the performance of pollinators. Such studies may potentially help to identify those species more resilient to climate change, as well as those that are most vulnerable.

Anthropogenic influences on bee foraging.

Efficient foraging is vital to bee fitness but is challenging in the Anthropocene.

Larval nutrition impacts survival to adulthood, body size and the allometric scaling of metabolic rate in adult honeybees.

Resting metabolic rate (RMR) is a fundamental physiological measure linked to numerous aspects of organismal function, including lifespan. Although dietary restriction in insects during larval growth/development affects adult RMR, the impact of the nutritional composition of larval diets (i.e. diet quality) on adult RMR has not been studied. Using in vitro rearing to control larval diet quality, we determined the effect of dietary protein and carbohydrate on honeybee survival to adulthood, time to eclosion, body mass/size and adult RMR. High carbohydrate larval diets increased survival to adulthood and time to eclosion compared with both low carbohydrate and high protein diets. Upon emergence, bees reared on the high protein diet were smaller and lighter than those reared on other diets, whilst those raised on the high carbohydrate diet varied more in body mass. Newly emerged adult bees reared on the high carbohydrate diet showed a significantly steeper increase in allometric scaling of RMR compared with those reared on other diets. This suggests that the nutritional composition of larval diets influences survival to adulthood, time to eclosion and the allometric scaling of RMR. Given that agricultural intensification and increasing urbanisation have led to a decrease in both forage availability and dietary diversity for bees, our results are critical to improving understanding of the impacts of poor developmental nutrition on bee growth/development and physiology.

Monitoring Neonicotinoid Exposure for Bees in Rural and Peri-urban Areas of the U.K. during the Transition from Pre- to Post-moratorium.

Concerns regarding the impact of neonicotinoid exposure on bee populations recently led to an EU-wide moratorium on the use of certain neonicotinoids on flowering crops. Currently, evidence regarding the impact, if any, the moratorium has had on bees' exposure is limited. We sampled pollen and nectar from bumblebee colonies in rural and peri-urban habitats in three U.K. regions: Stirlingshire, Hertfordshire, and Sussex. Colonies were sampled over three years: prior to the ban (2013), during the initial implementation when some seed-treated winter-sown oilseed rape was still grown (2014), and following the ban (2015). To compare species-level differences, in 2014 only, honeybee colonies in rural habitats were also sampled. Over half of all samples were found to be contaminated ( n = 408), with thiamethoxam being the compound detected at the highest concentrations in honeybee- (up to 2.29 ng/g in nectar in 2014, median ≤ 0.1 ng/g, n = 79) and bumblebee-collected pollen and nectar (up to 38.77 ng/g in pollen in 2013, median ≤ 0.12 ng/g, n = 76). Honeybees were exposed to higher concentrations of neonicotinoids than bumblebees in 2014. While neonicotinoid exposure for rural bumblebees declined post-ban (2015), suggesting a positive impact of the moratorium, the risk of neonicotinoid exposure for bumblebees in peri-urban habitats remained largely the same between 2013 and 2015.

A comparative analysis of colour preferences in temperate and tropical social bees.

The spontaneous occurrence of colour preferences without learning has been demonstrated in several insect species; however, the underlying mechanisms are still not understood. Here, we use a comparative approach to investigate spontaneous and learned colour preferences in foraging bees of two tropical and one temperate species. We hypothesised that tropical bees utilise different sets of plants and therefore might differ in their spontaneous colour preferences. We tested colour-naive bees and foragers from colonies that had been enclosed in large flight cages for a long time. Bees were shortly trained with triplets of neutral, UV-grey stimuli placed randomly at eight locations on a black training disk to induce foraging motivation. During unrewarded tests, the bees' responses to eight colours were video-recorded. Bees explored all colours and displayed an overall preference for colours dominated by long or short wavelengths, rather than a single colour stimulus. Naive Apis cerana and Bombus terrestris showed similar choices. Both inspected long-wavelength stimuli more than short-wavelength stimuli, whilst responses of the tropical stingless bee Tetragonula iridipennis differed, suggesting that resource partitioning could be a determinant of spontaneous colour preferences. Reward on an unsaturated yellow colour shifted the bees' preference curves as predicted, which is in line with previous findings that brief colour experience overrides the expression of spontaneous preferences. We conclude that rather than determining foraging behaviour in inflexible ways, spontaneous colour preferences vary depending on experimental settings and reflect potential biases in mechanisms of learning and decision-making in pollinating insects.

Larval exposure to field-realistic concentrations of clothianidin has no effect on development rate, over-winter survival or adult metabolic rate in a solitary bee, Osmia bicornis.

There is widespread concern regarding the effects of agro-chemical exposure on bee health, of which neonicotinoids, systemic insecticides detected in the pollen and nectar of both crops and wildflowers, have been the most strongly debated. The majority of studies examining the effect of neonicotinoids on bees have focussed on social species, namely honey bees and bumble bees. However, most bee species are solitary, their life histories differing considerably from these social species, and thus it is possible that their susceptibility to pesticides may be quite different. Studies that have included solitary bees have produced mixed results regarding the impact of neonicotinoid exposure on survival and reproductive success. While the majority of studies have focused on the effects of adult exposure, bees are also likely to be exposed as larvae via the consumption of contaminated pollen. Here we examined the effect of exposure of Osmia bicornis larvae to a range of field-realistic concentrations (0-10 ppb) of the neonicotinoid clothianidin, observing no effect on larval development time, overwintering survival or adult weight. Flow-through respirometry was used to test for latent effects of larval exposure on adult physiological function. We observed differences between male and female bees in the propensity to engage in discontinuous gas exchange; however, no effect of larval clothianidin exposure was observed. Our results suggest that previously reported adverse effects of neonicotinoids on O. bicornis are most likely mediated by impacts on adults.

Optimal search patterns in honeybee orientation flights are robust against emerging infectious diseases.

Lévy flights are scale-free (fractal) search patterns found in a wide range of animals. They can be an advantageous strategy promoting high encounter rates with rare cues that may indicate prey items, mating partners or navigational landmarks. The robustness of this behavioural strategy to ubiquitous threats to animal performance, such as pathogens, remains poorly understood. Using honeybees radar-tracked during their orientation flights in a novel landscape, we assess for the first time how two emerging infectious diseases (Nosema sp. and the Varroa-associated Deformed wing virus (DWV)) affect bees' behavioural performance and search strategy. Nosema infection, unlike DWV, affected the spatial scale of orientation flights, causing significantly shorter and more compact flights. However, in stark contrast to disease-dependent temporal fractals, we find the same prevalence of optimal Lévy flight characteristics (µ ≈ 2) in both healthy and infected bees. We discuss the ecological and evolutionary implications of these surprising insights, arguing that Lévy search patterns are an emergent property of fundamental characteristics of neuronal and sensory components of the decision-making process, making them robust against diverse physiological effects of pathogen infection and possibly other stressors.

Flight performance of actively foraging honey bees is reduced by a common pathogen.

Sudden and severe declines in honey bee (Apis mellifera) colony health in the US and Europe have been attributed, in part, to emergent microbial pathogens, however, the mechanisms behind the impact are unclear. Using roundabout flight mills, we measured the flight distance and duration of actively foraging, healthy-looking honey bees sampled from standard colonies, before quantifying the level of infection by Nosema ceranae and Deformed Wing Virus complex (DWV) for each bee. Neither the presence nor the quantity of N. ceranae were at low, natural levels of infection had any effect on flight distance or duration, but presence of DWV reduced flight distance by two thirds and duration by one half. Quantity of DWV was shown to have a significant, but weakly positive relation with flight distance and duration, however, the low amount of variation that was accounted for suggests further investigation by dose-response assays is required. We conclude that widespread, naturally occurring levels of infection by DWV weaken the flight ability of honey bees and high levels of within-colony prevalence are likely to reduce efficiency and increase the cost of resource acquisition. Predictions of implications of pathogens on colony health and function should take account of sublethal effects on flight performance.

No effect of low-level chronic neonicotinoid exposure on bumblebee learning and fecundity.

In recent years, many pollinators have declined in abundance and diversity worldwide, presenting a potential threat to agricultural productivity, biodiversity and the functioning of natural ecosystems. One of the most debated factors proposed to be contributing to pollinator declines is exposure to pesticides, particularly neonicotinoids, a widely used class of systemic insecticide. Also, newly emerging parasites and diseases, thought to be spread via contact with managed honeybees, may pose threats to other pollinators such as bumblebees. Compared to honeybees, bumblebees could be particularly vulnerable to the effects of stressors due to their smaller and more short-lived colonies. Here, we studied the effect of field-realistic, chronic clothianidin exposure and inoculation with the parasite Nosema ceranae on survival, fecundity, sugar water collection and learning using queenless Bombus terrestris audax microcolonies in the laboratory. Chronic exposure to 1 ppb clothianidin had no significant effects on the traits studied. Interestingly, pesticide exposure in combination with additional stress caused by harnessing bees for Proboscis Extension Response (PER) learning assays, led to an increase in mortality. In contrast to previous findings, the bees did not become infected by N. ceranae after experimental inoculation with the parasite spores, suggesting variability in host resistance or parasite virulence. However, this treatment induced a slight, short-term reduction in sugar water collection, potentially through stimulation of the immune system of the bees. Our results suggest that chronic exposure to 1 ppb clothianidin does not have adverse effects on bumblebee fecundity or learning ability.

Widespread contamination of wildflower and bee-collected pollen with complex mixtures of neonicotinoids and fungicides commonly applied to crops.

There is considerable and ongoing debate as to the harm inflicted on bees by exposure to agricultural pesticides. In part, the lack of consensus reflects a shortage of information on field-realistic levels of exposure. Here, we quantify concentrations of neonicotinoid insecticides and fungicides in the pollen of oilseed rape, and in pollen of wildflowers growing near arable fields. We then compare this to concentrations of these pesticides found in pollen collected by honey bees and in pollen and adult bees sampled from bumble bee colonies placed on arable farms. We also compared this with levels found in bumble bee colonies placed in urban areas. Pollen of oilseed rape was heavily contaminated with a broad range of pesticides, as was the pollen of wildflowers growing nearby. Consequently, pollen collected by both bee species also contained a wide range of pesticides, notably including the fungicides carbendazim, boscalid, flusilazole, metconazole, tebuconazole and trifloxystrobin and the neonicotinoids thiamethoxam, thiacloprid and imidacloprid. In bumble bees, the fungicides carbendazim, boscalid, tebuconazole, flusilazole and metconazole were present at concentrations up to 73nanogram/gram (ng/g). It is notable that pollen collected by bumble bees in rural areas contained high levels of the neonicotinoids thiamethoxam (mean 18ng/g) and thiacloprid (mean 2.9ng/g), along with a range of fungicides, some of which are known to act synergistically with neonicotinoids. Pesticide exposure of bumble bee colonies in urban areas was much lower than in rural areas. Understanding the effects of simultaneous exposure of bees to complex mixtures of pesticides remains a major challenge.

The canary in the coalmine; bee declines as an indicator of environmental health.

Bee declines have received much attention of late, but there is considerable debate and confusion as to the extent, significance and causes of declines. In part, this reflects conflation of data for domestic honeybees, numbers of which are largely driven by economic factors, with those for wild bees, many of which have undergone marked range contractions but for the majority of which we have no good data on population size. There is no doubt that bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined along with availability of suitable nest sites, bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites and pathogens accidentally spread by humans. Climate change is likely to exacerbate these problems in the future, particularly for cool- climate specialists such as bumblebees. Stressors do not act in isolation; for example pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple, interacting stressors is driving honeybee colony losses and declines of wild pollinators. Bees have a high profile and so their travails attract attention, but these same stressors undoubtedly bear upon other wild organisms, many of which are not monitored and have few champions. Those wild insects for which we do have population data (notably butterflies and moths) are overwhelmingly also in decline. We argue that bee declines are indicators of pervasive and ongoing environmental damage that is likely to impact broadly on biodiversity and the ecosystem services it provides.

Family dynamics and psychosocial functioning in children with SCI/D from Colombia, South America.

OBJECTIVE: The purpose of this study was to examine the connections between family dynamics and the psychosocial functioning of children with spinal cord injuries and disorders (SCI/D). DESIGN: Cross-sectional. SETTING: Participants were recruited from communities in Neiva, Colombia. PARTICIPANTS: Thirty children with SCI/D and their primary caregiver participated. Children were between 8 and 17 years of age, and had sustained their injury at least six months prior to data collection. INTERVENTIONS: NA. OUTCOME MEASURES: Participating children completed measures assessing their own psychosocial functioning (Children's Depression Inventory, Revised Children's Manifest Anxiety Scale-2, Pediatric Quality of Life Inventory), and their primary caregiver completed measures of family dynamics (Family Adaptability and Cohesion Evaluation Scale- Fourth Edition, Family Communication Scale, Family Assessment Device- General Functioning, Family Satisfaction Scale, Relationship-Focused Coping Scale). RESULTS: A correlation matrix showed a number of significant bivariate correlations between child and family variables, and three multiple regressions showed that family satisfaction, empathy, and flexibility significantly explained 27% of the variance in child worry; family satisfaction and communication explained 18% of the variance in child social anxiety; and family cohesion and communication explained 23% of the variance in child emotional functioning. CONCLUSIONS: These findings highlight the importance of rehabilitation professionals considering the association between family dynamics and the psychosocial functioning of children with SCI/D when working with this population.

Implementing a Trauma-Informed Approach in Pediatric Health Care Networks.

Pediatric health care networks serve millions of children each year. Pediatric illness and injury are among the most common potentially emotionally traumatic experiences for children and their families. In addition, millions of children who present for medical care (including well visits) have been exposed to prior traumatic events, such as violence or natural disasters. Given the daily challenges of working in pediatric health care networks, medical professionals and support staff can experience trauma symptoms related to their work. The application of a trauma-informed approach to medical care has the potential to mitigate these negative consequences. Trauma-informed care minimizes the potential for medical care to become traumatic or trigger trauma reactions, addresses distress, provides emotional support for the entire family, encourages positive coping, and provides anticipatory guidance regarding the recovery process. When used in conjunction with family-centered practices, trauma-informed approaches enhance the quality of care for patients and their families and the well-being of medical professionals and support staff. Barriers to routine integration of trauma-informed approaches into pediatric medicine include a lack of available training and unclear best-practice guidelines. This article highlights the importance of implementing a trauma-informed approach and offers a framework for training pediatric health care networks in trauma-informed care practices.

Pediatric SCI/D caregiver mental health and family dynamics in Colombia, South America.

OBJECTIVE: This study examined the connections between family dynamics and the mental health of caregivers of youth with spinal cord injuries/disorders (SCI/D) caregivers from Colombia, South America. It was hypothesized that lower family functioning would be associated with poorer caregiver mental health. METHODS: A cross-sectional study of self-report data collected from caregivers through the Hospital Universatario Hernando Moncaleano Perdomo in Neiva, Colombia. Thirty caregivers of children with SCI/D from Nevia, Colombia who were a primary caregiver for ≥3 months, providing care for an individual who was ≥6 months post-injury/diagnosis, familiar with the patient's history, and without neurological or psychiatric conditions. Caregivers' average age was 41.30 years (SD = 10.98), and 90% were female. Caregivers completed Spanish versions of instruments assessing their own mental health and family dynamics. RESULTS: Family dynamics explained 43.2% of the variance in caregiver burden and 50.1% of the variance in satisfaction with life, although family dynamics were not significantly associated with caregiver depression in the overall analysis. Family satisfaction was the only family dynamics variable to yield a significant unique association with any index of caregiver mental health (satisfaction with life). CONCLUSIONS: If similar findings emerge in future intervention research, interventions for pediatric SCI/D caregivers in Colombia and other similar global regions could benefit from including techniques to improve family dynamics, especially family satisfaction, given the strong potentially reciprocal connection between these dynamics and caregiver mental health. IMPLICATIONS FOR REHABILITATION: The degree of disability resulting from SCI/D can vary greatly depending on the severity and level of the lesion, though permanent impairment is often present that profoundly impacts both physical and psychological functioning. Very little is known about the impact of pediatric SCI/D in developing countries, despite the high rates of injury reported in these areas. Family interventions could contribute significantly to the lives of children with SCI/D and their families.

Differences in color learning between pollen- and sucrose-rewarded bees.

What bees learn during pollen collection, and how they might discriminate between flowers on the basis of the quality of this reward, is not well understood. Recently we showed that bees learn to associate colors with differences in pollen rewards. Extending these findings, we present here additional evidence to suggest that the strength and time-course of memory formation may differ between pollen- and sucrose-rewarded bees. Color-naïve honeybees, trained with pollen or sucrose rewards to discriminate colored stimuli, were found to differ in their responses when recalling learnt information after reversal training. Such differences could affect the decision-making and foraging dynamics of individual bees when collecting different types of floral rewards.

Neonicotinoid Residues in Wildflowers, a Potential Route of Chronic Exposure for Bees.

In recent years, an intense debate about the environmental risks posed by neonicotinoids, a group of widely used, neurotoxic insecticides, has been joined. When these systemic compounds are applied to seeds, low concentrations are subsequently found in the nectar and pollen of the crop, which are then collected and consumed by bees. Here we demonstrate that the current focus on exposure to pesticides via the crop overlooks an important factor: throughout spring and summer, mixtures of neonicotinoids are also found in the pollen and nectar of wildflowers growing in arable field margins, at concentrations that are sometimes even higher than those found in the crop. Indeed, the large majority (97%) of neonicotinoids brought back in pollen to honey bee hives in arable landscapes was from wildflowers, not crops. Both previous and ongoing field studies have been based on the premise that exposure to neonicotinoids would occur only during the blooming period of flowering crops and that it may be diluted by bees also foraging on untreated wildflowers. Here, we show that exposure is likely to be higher and more prolonged than currently recognized because of widespread contamination of wild plants growing near treated crops.

Caregiving in Dementia and its Impact on Psychological Functioning and Health-Related Quality of Life: Findings from a Colombian Sample.

Existing published studies about health-related quality of life (HRQOL) in caregivers of dementia patients living in Latin American countries are very limited. However, cultural aspects, personal values, and social structure may affect the way caregivers experience their role in different societies. The current study investigated the relationship between HRQOL and psychological factors using a cross-sectional design. The sample consisted of 102 informal caregivers of patients with dementia from Bogotá, Colombia, South America. Measures included the Patient Health Questionnaire (PHQ-9) for depression, the Satisfaction with Life Scale (SWLS), the Zarit Burden Interview, and the Short Health Questionnaire (SF36) for HRQOL. Canonical correlations revealed that there was a significant relationship between caregivers' mental health and HRQOL, such that caregivers with better satisfaction with life and less symptoms of depression had more vitality and better general health. There is a strong relationship between mental health and health-related quality of life in Colombian caregivers of dementia patients living in their country of origin. Specific aspects of mental health, including satisfaction with life and depression, need to be addressed in order to improve caregivers' quality of life. Given that mental health care resources may be scarce in Latin American countries, culturally appropriate interventions should focus on preventing/treating depression and promote life satisfaction, as a way to improve their quality of life.

Health related quality of life and mental health in children with SCI/D from Neiva, Colombia.

OBJECTIVE: To date, no research has been published on the health related quality of life (HRQOL) and mental health of children with spinal cord injury and disorders (SCI/D) in Latin America, although limited previous research in Western countries has demonstrated the debilitating and chronic nature of these conditions in children. The aim was to examine the connections between HRQOL and mental health in children with SCI/D from Neiva, Colombia. STUDY DESIGN: Thirty children (8- 17 years) were recruited from the Hospital Universatario Hernando Mocaleano Perdomo in Neiva, Colombia. Participants completed self-report measures administered verbally by trained research staff. RESULTS: A correlation matrix generally suggested that higher HRQOL was robustly associated with better mental health. A series of multiple regressions found that HRQOL explained 50.5% of the variance in children's depression, 31.5% of the variance in worry, and 41.9% of the variance in social anxiety. Within these regressions, emotional and social functioning were uniquely associated with depression, and emotional functioning was uniquely associated with social anxiety. CONCLUSION: This is the first published study to examine psychosocial outcomes in children with SCI/D in Latin America, and its findings suggest that future research and interventions for children with SCI/D in Colombia - and possibly in other regions of Latin America - would benefit from emphasizing emotional and social functioning.