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A new Internet service is providing answers to wide-ranging questions about honey bees--free of charge. Called the Expert Forum on Honey Bees, it lists a wide range of frequently asked [...]

The dynamics of viruses are critical to our understanding of disease pathogenesis. Using honey bee Deformed wing virus (DWV) as a model, we conducted field and laboratory studies to investigate the roles of abiotic and biotic stress factors as well as host health conditions in dynamics of virus replication in honey bees. The results showed that temperature decline could lead to not only significant decrease in the rate for pupae to emerge as adult bees, but also an increased severity of the virus infection in emerged bees, partly explaining the high levels of winter losses of managed honey bees, Apis mellifera, around the world. By experimentally exposing adult bees with variable levels of parasitic mite Varroa destructor, we showed that the severity of DWV infection was positively correlated with the density and time period of Varroa mite infestation, confirming the role of Varroa mites in virus transmission and activation in honey bees. Further, we showed that host conditions have a significant impact on the outcome of DWV infection as bees that originate from strong colonies resist DWV infection and replication significantly better than bee originating from weak colonies. The information obtained from this study has important implications for enhancing our understanding of host-pathogen interactions and can be used to develop effective disease control strategies for honey bees. [ABSTRACT FROM AUTHOR]

The African honey bee subspecies Apis mellifera scutellata has colonized much of the Americas in less than 50 years and has largely replaced European bees throughout its range in the New World. The African bee therefore provides an excellent opportunity to examine the factors that influence invasion success. We provide a synthesis of recent research on the African bee, concentrating on its ability to displace European honey bees. Specifically, we consider (a) the genetic composition of the expanding population and the symmetry of gene flow between African and European bees, (b) the mechanisms that favor the preservation of the African genome, and (c) the possible range and impact of the African bee in the United States. [ABSTRACT FROM AUTHOR]

The article offers information on a report which presents a meta-analysis tool that analyzes sequence and expression data, and reveals a flexible cis-regulatory code underlying a complex honey bee behavioral maturation. It reflects that the tool will help the scientists for conducting integrative analyses of the multitude of generated datasets. It provides information that complex phenotypes are produced by a multitude of heritable and environmental determinants.

[Display omitted] • Microsporidia parasite Nosema ceranae and Black queen cell virus are significant predictors of overwintering colony losses when the prevalence of Deformed wing virus is low after acaricide treatment. • The major royal jelly proteins (MRJPs) not only play nutritional roles in honey bees but also are linked to honey bees' immune responses. Therefore, they can serve as molecular markers for measuring overwintering stress in honey bees. • Sirtuin signaling pathway is the most significantly suppressed pathway in overwintering diseased bees. • SIRT1, a major sirtuin protein that regulates energy and immune metabolism, was significantly downregulated in bees merely exposed to cold challenges. Activation of SIRT1 expression by SRT1720, a SIRT1 activator, could improve the physiology and extend the lifespan of cold-stressed bees. Honey bees provides valuable pollination services for world food crops and wild flowering plants which are habitats of many animal species and remove carbon dioxide from the atmosphere, a powerful tool in the fight against climate change. Nevertheless, the honey bee population has been declining and the majority of colony losses occur during the winter. The goal of this study was to understand the mechanisms underlying overwinter colony losses and develop novel therapeutic strategies for improving bee health. First, pathogen prevalence in overwintering bees were screened between 2015 and 2018. Second, RNA sequencing (RNA-Seq) for transcriptional profiling of overwintering honey bees was conducted and qRT-PCR was performed to confirm the results of the differential expression of selected genes. Lastly, laboratory bioassays were conducted to measure the effects of cold challenges on bee survivorship and stress responses and to assess the effect of a novel medication for alleviating cold stress in honey bees. We identified that sirtuin signaling pathway is the most significantly enriched pathway among the down-regulated differentially expressed genes (DEGs) in overwintering diseased bees. Moreover, we showed that the expression of SIRT1 gene, a major sirtuin that regulates energy and immune metabolism, was significantly downregulated in bees merely exposed to cold challenges, linking cold stress with altered gene expression of SIRT1. Furthermore, we demonstrated that activation of SIRT1 gene expression by SRT1720, an activator of SIRT1 expression, could improve the physiology and extend the lifespan of cold-stressed bees. Our study suggests that increased energy consumption of overwintering bees for maintaining hive temperature reduces the allocation of energy toward immune functions, thus making the overwintering bees more susceptible to disease infections and leading to high winter colony losses. The novel information gained from this study provides a promising avenue for the development of therapeutic strategies for mitigating colony losses, both overwinter and annually. [ABSTRACT FROM AUTHOR]

Background: Bees are confronting several environmental challenges, including the intermingled effects of malnutrition and disease. Intuitively, pollen is the healthiest nutritional choice, however, commercial substitutes, such as Bee-Pro and MegaBee, are widely used. Herein we examined how feeding natural and artificial diets shapes transcription in the abdomen of the honey bee, and how transcription shifts in combination with Nosema parasitism. Results: Gene ontology enrichment revealed that, compared with poor diet (carbohydrates [C]), bees fed pollen (P > C), Bee-Pro (B > C), and MegaBee (M > C) showed a broad upregulation of metabolic processes, especially lipids; however, pollen feeding promoted more functions, and superior proteolysis. The superiority of the pollen diet was also evident through the remarkable overexpression of vitellogenin in bees fed pollen instead of MegaBee or Bee-Pro. Upregulation of bioprocesses under carbohydrates feeding compared to pollen (C > P) provided a clear poor nutritional status, uncovering stark expression changes that were slight or absent relatively to Bee-Pro (C > B) or MegaBee (C > M). Poor diet feeding (C > P) induced starvation response genes and hippo signaling pathway, while it repressed growth through different mechanisms. Carbohydrate feeding (C > P) also elicited ‘adult behavior’, and developmental processes suggesting transition to foraging. Finally, it altered the ‘circadian rhythm’, reflecting the role of this mechanism in the adaptation to nutritional stress in mammals. Nosema-infected bees fed pollen compared to carbohydrates (PN > CN) upheld certain bioprocesses of uninfected bees (P > C). Poor nutritional status was more apparent against pollen (CN > PN) than Bee-Pro (CN > BN) or MegaBee (CN > MN). Nosema accentuated the effects of malnutrition since more starvation-response genes and stress response mechanisms were upregulated in CN > PN compared to C > P. The bioprocess ‘Macromolecular complex assembly’ was also enriched in CN > PN, and involved genes associated with human HIV and/or influenza, thus providing potential candidates for bee-Nosema interactions. Finally, the enzyme Duox emerged as essential for guts defense in bees, similarly to Drosophila. Conclusions: These results provide evidence of the superior nutritional status of bees fed pollen instead of artificial substitutes in terms of overall health, even in the presence of a pathogen. [ABSTRACT FROM AUTHOR]

Introduces BK-ECONOMICS (`BK' stands for beekeeping), a free computer program available from Agricultural Research Service (ARS) scientists, includes a spread-sheet to track loans and equipment, labor, vehicle, and insurance expenditures. Features of the database component; Use of the program; Availability of the program.

Honey bee queens mate with multiple males resulting in high intracolonial genetic diversity among nestmates; a reproductive strategy known as extreme polyandry. Several studies have demonstrated the adaptive significance of extreme polyandry for overall colony performance and colony growth. Colonies that are more genetically diverse collect more pollen than colonies with less diversity. However, the effects of intracolonial genetic diversity on worker nutritional status are unknown. We created colonies headed by queens instrumentally inseminated with sperm from either 1 or 20 drones, then compared protein consumption, digestion, and uptake among nestmates. We found that nurse bees from colonies with multiple-drone-inseminated (MDI) queens consumed more pollen, had lower amounts of midgut tissue protease, and invested more protein into larvae than nurse bees from single-drone-inseminated (SDI) queens. Pollen foragers from MDI colonies had significantly higher hemolymph protein concentration than pollen foragers from SDI colonies. Differences in hemolymph protein concentration between nurses and pollen foragers were significantly smaller among MDI colonies than among SDI colonies. While intracolonial genetic diversity is correlated with increased foraging, our results suggest that this relationship may be driven in part by the elevated resource demands of nurse bees in genetically diverse colonies that consume and distribute more protein in response to the social context within the hive. [ABSTRACT FROM AUTHOR]

• The non-linear DDE model is used to study honeybee-mite population dynamics with seasonality. • Mites and age structure can destabilize population dynamics that leads colony to collapse. • The queen's egg-laying rate has the greatest effect on colony size. • Seasonality in the egg-laying rate can either promote or suppress the colony survival at different conditions. Honeybees play an important role in the production of many agricultural crops and in sustaining plant diversity in undisturbed ecosystems. The rapid decline of honeybee populations have sparked great concern worldwide. Field and theoretical studies have shown that the parasitic Varroa mite (Varroa destructor Anderson and Trueman) could be the main reason for colony losses. In order to understand how mites affect population dynamics of honeybees and the health of a colony, we propose a brood-adult bee-mite interaction model in which the time lag from brood to adult bee is taken into account. Noting that the temporal dynamics of a honeybee colony varies with respect to season, we validate the model and perform parameter estimations under both constant and fluctuating seasonality scenarios. Our analytical and numerical studies reveal the following: (a) In the presence of parasite mites, the large time lag from brood to adult bee could destabilize population dynamics and drive the colony to collapse; however the small natural mortality of the adult bee population can promote a mite-free colony when time lag is small or at an intermediate level; (b) Small brood' infestation rates could stabilize all populations at the unique interior equilibrium under constant seasonality while may drive the mite population to die out when seasonality is taken into account; (c) High brood' infestation rates can destabilize the colony dynamics leading to population collapse depending on initial population size under constant and seasonal conditions; (d) Results from our sensitivity analysis indicate that the queen's egg-laying may have the greatest effect on colony population size.The death rate of the brood and the colony size at which brood survivability is the half maximal were also shown to be highly sensitive with an inverse correlation to the colony population size. Our results provide insights on the effects of seasonality on the dynamics. For example, mites may die out leaving a healthy colony with brood and adult bees in the presence of seasonality while the colony collapses without seasonality. [ABSTRACT FROM AUTHOR]

Vairimorpha (Microsporidia: Nosematidae) is a microsporidian that infects honey bees especially in winter. Fumagillin can reduce infections, but whether overwintering survival is improved is unclear. The diet also may influence the severity of Nosema infections. We examined the relationship between Nosema and colony size and survival in hives overwintered in cold storage facilities. In year 1, no Fumagillin treatments were applied. Colony size and survival after cold storage and almond bloom were comparable between groups with high and low pre-cold storage infections. In year 2, size and survival were compared among colonies with and without Fumagillin treatment that were fed either pollen or protein supplement prior to overwintering. Colonies treated with Fumagillin had lower spore numbers than untreated, but colony sizes and survival were similar among the treatments. However, more colonies with zero spores per bee could be rented for almond pollination and were alive after bloom than those averaging >1 million spores per bee. Fat body metrics can affect overwintering success. In both years, fat body weights and protein concentrations increased, and lipid concentrations decreased while bees were in cold storage. Fat body metrics did not differ with Nosema infection levels. However, Fumagillin negatively affected pre-cold storage fat body protein concentrations and colony sizes after cold storage and almond bloom. Treating with Fumagillin before overwintering in cold storage might result in greater colony survival if spore numbers are high, but undetectable or even negative effects when spore numbers are low., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America.)

Honey bees and other pollinators are critical for food production and nutritional security but face multiple survival challenges. The effect of climate change on honey bee colony losses is only recently being explored. While correlations between higher winter temperatures and greater colony losses have been noted, the impacts of warmer autumn and winter temperatures on colony population dynamics and age structure as an underlying cause of reduced colony survival have not been examined. Focusing on the Pacific Northwest US, our objectives were to (a) quantify the effect of warmer autumns and winters on honey bee foraging activity, the age structure of the overwintering cluster, and spring colony losses, and (b) evaluate indoor cold storage as a management strategy to mitigate the negative impacts of climate change. We perform simulations using the VARROAPOP population dynamics model driven by future climate projections to address these objectives. Results indicate that expanding geographic areas will have warmer autumns and winters extending honey bee flight times. Our simulations support the hypothesis that late-season flight alters the overwintering colony age structure, skews the population towards older bees, and leads to greater risks of colony failure in the spring. Management intervention by moving colonies to cold storage facilities for overwintering has the potential to reduce honey bee colony losses. However, critical gaps remain in how to optimize winter management strategies to improve the survival of overwintering colonies in different locations and conditions. It is imperative that we bridge the gaps to sustain honey bees and the beekeeping industry and ensure food and nutritional security., (© 2024. The Author(s).)