Explore the vast range of titles available.

To improve health and vitality of honey bees ( Apis mellifera ) beekeepers can propagate stocks that demonstrate resistance to both parasites and pathogens. Most breeding programs focus on resistance to Varroa destructor mites and/or brood pathogens. Colonies bred specifically for the trait Varroa Sensitive Hygiene (VSH), exhibit a high level of resistance to the parasitic mites. Still, they have never been explicitly tested for resistance to brood diseases. The goal of this study was to test if colonies bred for VSH are both mite and disease resistant. Over two years (2023 and 2024) and in two locations (University of Minnesota and the USDA-ARS lab in Baton Rouge, Louisiana), we compared colonies from the Pol-line bred specifically for VSH to colonies from a commercial source. The Commercial colonies in this study were not selected specifically for Varroa resistance but were selected for “general” hygienic behavior using the freeze-killed brood (FKB) assay. We challenged colonies within each line with Ascosphara apis, a fungus that causes chalkbrood, and quantified mites, disease and hygienic behavior. Our study demonstrated that bees from the Pol-line bred for VSH are just as resistant to chalkbrood as bees from a commercial line bred for hygienic behavior. Results confirmed that the Pol-line was more mite resistant than the Commercial, as it had significantly lower mites in two of three trials. Both the Pol-line and Commercial colonies had high levels of hygienic behavior. These results indicate that VSH-selected honey bees respond to both mite-infested and disease-infected brood. Further comparative studies are needed to clarify any differences in genetic mechanisms and olfactory sensitivity mediating the VSH-trait and general hygienic behavior. On a practical level, using honey bees selected for VSH in beekeeping operations could help curb losses, improve honey bee health, and reduce financial burdens caused by Varroa and diseases.

Honey bees ( Apis mellifera ) play a pivotal role in agricultural production worldwide, primarily through the provision of pollination services. But despite their importance, honey bee health continues to be threatened by many factors, including parasitization by the mite Varroa destructor , poor queen quality, and pesticide exposure. Accumulation of pesticides in the hive’s comb matrix over time inevitably leads to the exposure of developing brood, including queens, to wax contaminated with multiple compounds. Here, we characterized the brain transcriptome of queens that were reared in wax contaminated with pesticides commonly found in commercial beekeeping operations including either (a) a combination of 204,000 ppb of tau -fluvalinate and 91,900 ppb of coumaphos (“FC” group), (b) a combination of 9,800 ppb of chlorpyrifos and 53,700 ppb of chlorothalonil (“CC” group), or (c) 43,000 ppb of amitraz (“A” group). Control queens were reared in pesticide-free wax. Adult queens were allowed to mate naturally before being dissected. RNA isolated from brain tissue from three individuals per treatment group was sequenced using three technical replicates per queen. Using a cutoff log 2 fold-change value of 1.5, we identified 247 differentially expressed genes (DEGs) in the FC group, 244 in the CC treatment group, and 668 in the A group, when comparing each group to the control. This is the first study to examine the sublethal effects of pesticides commonly found in wax (particularly amitraz) on the queen’s brain transcriptome. Future studies should further explore the relationship between our molecular findings and the queen’s behavior and physiology.

When engaging with socioscientific issues, learners act at the intersection of scientific, school, and other societal communities, drawing on knowledge, practices, and identities from both in and out of the classroom to address problems as national or global citizens. We present three case studies of high school students whose classroom participation in a unit on the politically polarizing topic of climate change was informed by their political identities and how they situated themselves in climate change's sociocultural, historical, and geologic context. We describe how these students, including two who initially rejected human-influenced climate change but revised their understandings, negotiating dissonant identities in the classroom through repeated engagement with conflicting political and scientific values, knowledge, and beliefs. These case studies problematize building bridges between formal and informal learning experiences and suggest that it may be necessary to leverage disconnections in addition to building connections across settings to promote productive identity work. The results further suggest that supporting climate change learning includes attending to identity construction across ecosocial timescales, including geologic time.

Honey bee viruses are serious pathogens that can cause poor colony health and productivity. We analyzed a multi-year longitudinal dataset of abundances of nine honey bee viruses (deformed wing virus A, deformed wing virus B, black queen cell virus, sacbrood virus, Lake Sinai virus, Kashmir bee virus, acute bee paralysis virus, chronic bee paralysis virus, and Israeli acute paralysis virus) in colonies located across Canada to describe broad trends in virus intensity and occurrence among regions and years. We also tested climatic variables (temperature, wind speed, and precipitation) as predictors in an effort to understand possible drivers underlying seasonal patterns in viral prevalence. Temperature was a significant positive predictor of the total number of viruses per sample, which was highest in British Columbia (mean = 5.0). Lake Sinai virus (LSV) was the most prevalent overall (at 89%) and had the highest infection intensity, at an average of 3.9 × 10 8 copies per bee. Acute bee paralysis virus was the least prevalent virus (at 4.7%) and had the lowest infection intensity (1.9 × 10 5 copies per bee). Surprisingly, including Varroa abundance as a covariate did not significantly improve model fit for any virus. All viruses, except Kashmir bee virus, varied by region, and one or more climatic variables were significant predictors for six of the nine viruses. Although climatic effects were often inconsistent among individual viruses, we show that climatic variables can be better predictors of virus intensity and occurrence than Varroa mite abundance, at least when infestation rates are low.

Honey bee pollination of entomophilous commercial crops is a major input in agricultural management yet unlike irrigation, fertilisation and plant protection have yet to be integrated into precision agriculture practices. This study examines colony strength as a key determinant of efficient pollination. Over three years and across two study sites, we evaluated the relationship between colony strength (frames of bees, FOBs) and colony productivity using continuous hive weight monitoring. Hive weight data were analysed for both absolute gains and relative gains normalised per FOB across colony strengths. In all study periods, stronger colonies showed disproportionately higher weight gains compared to weaker colonies. For each additional FOB, the average increase in normalised weight gain ranged from 0.1 to 0.41 kg per colony, indicating a non-linear relationship between colony strength and productivity. An efficiency factor calculated for groups of strong and weak colonies ranged from 1.2 to 2.6, depending on the season and crop. Moreover, during periods of forage dearth, strong colonies exhibited lower weight losses than the weak colonies per FOB, making them more efficient under resource limited conditions. Our findings demonstrate that colony strength significantly influences foraging efficiency and colony resilience, ultimately supporting the conclusion that fewer stronger colonies will improve pollination outcomes while reducing the economic and environmental costs associated with commercial pollination services.

Widespread use of agrochemicals in the U.S. has led to nearly universal contamination of beeswax in honey bee hives. The most commonly found agrochemicals in wax include beekeeper-applied miticides containing tau-fluvalinate, coumaphos, or amitraz, and field-applied pesticides containing chlorothalonil or chlorpyrifos. Wax contaminated with these pesticides negatively affects the reproductive quality of queens and drones. However, the synergistic effects of these pesticides on the growth and survival of incipient colonies remain understudied. We established new colonies using frames with wax foundation that was pesticide free or contaminated with field-relevant concentrations of amitraz alone, a combination of tau-fluvalinate and coumaphos, or a combination of chlorothalonil and chlorpyrifos. Colony growth was assessed by estimating comb and brood production, food storage, and adult bee population during a colony’s first season. We also measured colony overwintering survival. We found no significant differences in colony growth or survivorship between colonies established on pesticide-free vs. pesticide-laden wax foundation. However, colonies that had Varroa destructor levels above 3% in the fall were more likely to die over winter than those with levels below this threshold, indicating that high Varroa infestation in the fall played a more important role than initial pesticide exposure of wax foundation in the winter survival of newly established colonies.

Pollinator diversity and abundance in North America have been at a steep decline over the last two decades due to the combinatorial effects of several environmental and anthropogenic stressors. In particular, managed honey bees (Apis mellifera) face multiple health risks including nutritional stress, exposure to pests and pathogens, poor queen quality, and pesticide contamination, which cause problems at the individual and colony levels. One of the gravest problems faced by honey bees is parasitization by the mite Varroa destructor, which is typically controlled through the application of miticides such as tau-fluvalinate, coumaphos, and amitraz. In addition to miticides, colonies are also exposed to pesticides brought by foragers from agricultural settings, including the fungicide chlorothalonil and the insecticide chlorpyrifos. Here, we explored whether exposure of wax to combinations of these pesticides during development affects honey bee queen physiology and worker behavior. To do this, we reared queens in plastic cups coated with molten beeswax that was either pesticide-free or containing field-relevant concentrations of tau-fluvalinate and coumaphos, amitraz, or chlorothalonil and chlorpyrifos. Once queens mated naturally, we placed them in observation hives to measure egg-laying rate and worker retinue size. We then dissected the queens and used the contents of their mandibular glands to measure worker attractiveness in caged bioassays and to analyze their chemical components using GC-MS. Exposure of wax to field-relevant concentrations of the tested pesticides during queen development significantly lowered the adult queens’ egg-laying rate and worker retinue size. Miticide exposure during development also lowered the attractiveness of queen mandibular gland contents to workers and affected the relative amounts of the glands’ chemical components. Our results support the ideas that mandibular gland pheromones act as honest indicators of queen reproductive fitness and that pesticide exposure of wax during bee development is an important and concerning factor impairing honey bee health.

Abstract Honey bees are the most important managed insect pollinators in the US and Canadian crop systems. However, the annual mortality of colonies in the past 15 years has been consistently higher than historical records. Because they are eusocial generalist pollinators and amenable to management, honey bees provide a unique opportunity to investigate a wide range of questions at molecular, organismal, and ecological scales. Here, the American Association of Professional Apiculturists (AAPA) and the Canadian Association of Professional Apiculturists (CAPA) created 2 collections of articles featuring investigations on micro and macro aspects of honey bee health, sociobiology, and management showcasing new applied research from diverse groups studying honey bees (Apis mellifera) in the United States and Canada. Research presented in this special issue includes examinations of abiotic and biotic stressors of honey bees, and evaluations and introductions of various stress mitigation measures that may be valuable to both scientists and the beekeeping community. These investigations from throughout the United States and Canada showcase the wide breadth of current work done and point out areas that need further research.

Nutritional deprivation is known to contribute to increased honey bee mortality, physiological stress, aberrant behaviors, and disease incidence. To investigate the effect of a realistic nutritional protein deficiency, we simulated a pollen dearth in half of our experimental colonies by robbing incoming foragers of their pollen loads, the primary source of dietary protein, at the colony entrance. We then conducted temperament assays on each colony weekly for pollen deprived and control counterparts. We also identified the plant species bees foraged from and took various physiological measures of honey bee nutritional status including gland size, lipid quantification, and gene expression to further investigate and explain our behavioral results. We found that colonies deprived of pollen reacted by becoming more defensive and that immature bees likely receive cues during rearing which prime their gene expression and behavior as adults, ultimately suggesting that environmental stress caused significant behavioral changes. Temperament is primarily associated with genotype in the literature, but there are environmental cues that are less acknowledged and still important as our study shows. As droughts become increasingly frequent and resource availability therefore changes over time, the impacts on behaviors of agricultural keystone species need additional consideration in order to form scientifically driven best management practices.

Nutritional deprivation is known to contribute to increased honey bee mortality, physiological stress, aberrant behaviors, and disease incidence. To investigate the effect of a realistic nutritional protein deficiency, we simulated a pollen dearth in half of our experimental colonies by robbing incoming foragers of their pollen loads, the primary source of dietary protein, at the colony entrance. We then conducted temperament assays on each colony weekly for pollen deprived and control counterparts. We also identified the plant species bees foraged from and took various physiological measures of honey bee nutritional status including gland size, lipid quantification, and gene expression to further investigate and explain our behavioral results. We found that colonies deprived of pollen reacted by becoming more defensive and that immature bees likely receive cues during rearing which prime their gene expression and behavior as adults, ultimately suggesting that environmental stress caused significant behavioral changes. Temperament is primarily associated with genotype in the literature, but there are environmental cues that are less acknowledged and still important as our study shows. As droughts become increasingly frequent and resource availability therefore changes over time, the impacts on behaviors of agricultural keystone species need additional consideration in order to form scientifically driven best management practices.