An Overview of the Effect of Prebiotics, Probiotics and Postbiotics on Internal Honeybee Parasite Nosema spp

Pollinators play vital roles to the environment, biodiversity conservation, food security and several dimensions of global sustainable development. Honey bee is an important pollinator globally but has been exposed to increasing threats from diseases, pesticides and biotic stresses. This review paper highlights the role of honey bees as pollinators, addresses threats which influence decline of honey bees and assess pesticidal risk toxicity on non-target organisms. Decline of honey bee population is caused by several factors including habitat fragmentation, pesticidal toxicity, colony collapse disorder and climate change. Pesticidal residue and toxicity has an adverse effect which results in honey bee population decline, disturb foraging and contamination of bee products. Residues of agricultural pesticides like pyrethroid and neonicotinoid pose a serious threat on honey bee health further reducing agricultural production and diversity. Pesticidal risk assessments are carried out to study effects of pesticides on pollinators with an aim to provide measures to safeguard their abundance, diversity and health. Sustainable agriculture, effective policy and proper management can decrease pollinators' risk by helping to diversify the agriculture for pollen and nectars with reduced usage of pesticides and proper management.

In this article, we explore the politics of expertise in an ongoing controversy in the United States over the role of certain insecticides in colony collapse disorder – a phenomenon involving mass die-offs of honey bees. Numerous long-time commercial beekeepers contend that newer systemic agricultural insecticides are a crucial part of the cocktail of factors responsible for colony collapse disorder. Many scientists actively researching colony collapse disorder reject the beekeepers’ claims, citing the lack of conclusive evidence from field experiments by academic and industry toxicologists. US Environmental Protection Agency regulators, in turn, privilege the latters’ approach to the issue, and use the lack of conclusive evidence of systemic insecticides’ role in colony collapse disorder to justify permitting these chemicals to remain on the market. Drawing on semistructured interviews with key players in the controversy, as well as published documents and ethnographic data, we show how a set of research norms and practices from agricultural entomology came to dominate the investigation of the links between pesticides and honey bee health, and how the epistemological dominance of these norms and practices served to marginalize the knowledge claims and policy positions of commercial beekeepers in the colony collapse disorder controversy. We conclude with a discussion of how the colony collapse disorder case can help us think about the nature and politics of expertise.

Honey bee (Apis mellifera) health has been severely impacted by multiple environmental stressors including parasitic infection, pesticide exposure, and poor nutrition. The decline in bee health is therefore a complex multifactorial problem which requires a holistic investigative approach. Within the exposome paradigm, the combined exposure to the environment, drugs, food, and individuals’ internal biochemistry affects health in positive and negative ways. In the context of the exposome, honey bee hive infection with parasites such as Nosema ceranae is also a form of environmental exposure. In this study, we hypothesized that exposure to xenobiotic pesticides and other environmental chemicals increases susceptibility to N. ceranae infection upon incidental exposure to the parasite. We further queried whether these exposures could be linked to changes in conserved metabolic biological pathways. From 30 hives sampled across 10 sites, a total of 2,352 chemical features were found via gas chromatography-time of flight mass spectrometry (GC-TOF) in extracts of honey bees collected from each hive. Of these, 20 pesticides were identified and annotated, and found to be significantly associated with N. ceranae infection. We further determined that infected hives were linked to a greater number of xenobiotic exposures, and the relative concentration of the exposures were not linked to the presence of a N. ceranae infection. In the exposome profiles of the bees, we also found chemicals inherent to known biological metabolic pathways of Apis mellifera and identified 9 dysregulated pathways. These findings have led us to posit that for hives exposed to similar chemicals, those that incur multiple, simultaneous xenobiotic stressors have a greater incidence of infection with N. ceranae. Mechanistically, our results suggests the overwhelming nature of these exposures negatively affects the biological functioning of the bee, and could explain how the decline in bee populations is associated with pesticide exposures.

Korea’s unique climate and agricultural environment suggest that the gut microbiome of honey bees may possess distinctive compositions influenced by regional factors. With the decline in honey bee populations and rising health challenges, understanding the role of gut microbiomes is essential for enhancing honey bee health and their resilience to environmental stressors. To explore caste-specific gut microbiota and identify microbial signatures associated with honey bee health, this study examined the gut microbial composition of worker bees, queen bees, and drones of Apis mellifera using 16S rRNA gene amplicon sequencing. Analysis of beta diversity and species richness demonstrated significant differences between worker bees and both drones and queens, with no significant differences identified between drones and queens. Notably, Lactobacillus dominated all groups, comprising 98.6% of the drones, 95.4% of the queens, and 68.3% of the workers. Additionally, Bombella was prominent in queens (4%), whereas Gilliamella (23%) and Frischella (4.7%) were notably enriched in workers. Drones and queens exhibited similar gut microbiome profiles, while workers displayed distinctly different compositions. These findings underscore the variation in gut microbiota composition and potential functional roles across honey bee castes. Such microbial distinctions may reflect caste-specific roles and physiological demands within the colony. Future research should investigate the physiological roles of gut microbiota and their contributions to environmental resilience, paving the way for microbiome-based strategies to promote honey bee health. This study lays a crucial scientific foundation for conserving the honey bee ecosystem and promoting sustainable agriculture.

Simple SummaryHoney bees are key pollinators in agricultural crops. Today, honey bee colonies in decline are a global concern as a result of various stressors, including pesticides, pathogens, honey bee health, and parasites. A healthy honey bee colony refers to colonies that are not exposed to biotic and abiotic stressors. In this study, we examine how thiamethoxam (pesticide) and deformed wing virus type A (DWV-A) interact in effects on honey bee health. The results revealed that the honey bees were infected with DWV-A and were additionally exposed to thiamethoxam, showing effects that increased the mortality rate, and crippled wings in newly emerged adult honey bees. Moreover, the exposure to thiamethoxam and DWV-A injection resulted in induced expression of immune genes (hymenoptaecin gene) while downregulation of two apoptosis genes (caspase8-like, caspase9-like genes). The impact interaction of pesticide and DWV-A have on the expression of apoptosis genes can directly affect viral susceptibility in the honey bee host.Honey bees are economically important insects for crop pollination. They play a significant role as pollinators of wild plants and agricultural crops and produce economical products, such as honey, royal jelly, wax, pollen, propolis, and venom. Despite their ecological and economical importance, the global honey bee population is in decline due to factors including pathogens, parasites, intensive agriculture, and pesticides. Moreover, these factors may be interlinked and exacerbate the loss of honey bees. This study aimed to investigate the interaction between a pesticide, thiamethoxam, and deformed wing virus type A (DWV-A) to honey bees and the effects on survival rate, wing characteristics, and expression of immune and apoptosis genes in Apis mellifera. We described the potential interaction between thiamethoxam and DWV-A on honey bee wing characteristics, DWV-A loads, and the expressions of immune (defensin, abaecin, and hymenoptaecin) and apoptosis genes (buffy, apaf1, caspase3-like, caspase8-like, and caspase9-like). Honey bee larvae were fed with three different thiamethoxam doses (0.001, 1.4, and 14.3 ng/µL of the diet). Then, thiamethoxam-treated white-eyed pupae were injected with 107 copy numbers/honey bee of the DWV-A genome. The interaction between thiamethoxam and DWV-A caused a high mortality rate, crippled wings in newly emerged adult honey bees (100%), and resulted in induced expression of hymenoptaecin gene compared to the control group, while downregulation of caspase8-like, caspase9-like genes compared to the DWV injection group. Therefore, the potential interaction between thiamethoxam and DWV-A might have a deleterious effect on honey bee lifespan. The results from this study could be used as a tool to combat DWV-A infection and mitigate pesticide usage to alleviate the decrease in the honey bee population.

Honey bees play an important agricultural and ecological role as pollinators of numerous agricultural crops and other plant species. Therefore, investigating the factors associated with high annual losses of honey bee colonies in the US is an important and active area of research. Pathogen incidence and abundance correlate with Colony Collapse Disorder- (CCD-) affected colonies in the US and colony losses in the US and in some European countries. Honey bees are readily infected by single-stranded positive sense RNA viruses. Largely dependent on the host immune response, virus infections can either remain asymptomatic or result in deformities, paralysis, or death of adults or larvae. RNA interference (RNAi) is an important antiviral defense mechanism in insects, including honey bees. Herein, we review the role of RNAi in honey bee antiviral defense and highlight some parallels between insect and mammalian immune systems. A more thorough understanding of the role of pathogens on honey bee health and the immune mechanisms bees utilize to combat infectious agents may lead to the development of strategies that enhance honey bee health and result in the discovery of additional mechanisms of immunity in metazoans.

Honey bee (Apis mellifera L.) populations have undergone a dramatic decline as an outcome of an increasing incidence of colony collapse disorder (CCD). The honey bee is a unique keystone species because its pollination activities are not only necessary for the viability of many flowering plant species in the wild, but are also necessary for many human agricultural practices. The increasing prevalence of CCD is a threat to the economic and nutritional security of all societies that rely on efficient pollination for large monoculture crops. Although there is ample evidence that Varroa mites, pesticides, disease, and climate change contribute to CCD, only a few studies have investigated the contribution of synergism across multiple factors to the development of CCD and CCD-like symptoms. However, there is increasing acknowledgement in the scientific community that synergism across different factors affects honey bee colony health and behavior. Here, we provide evidence that sub-lethal levels of imidacloprid neonicotinoid pesticide reduce learning and memory capabilities. Synergistic effects become apparent when Varroa mites together with imidacloprid exposure to individual bees more than doubled average mortality and attrition per trial.

The Latin American subcontinent contains some of the world’s major honey producing and exporting countries, but the status of bee health in this part of the world has not been clearly documented. There have been no reports of massive colony losses in Latin America, at least from the symptoms of CCD (colony collapse disorder) or in the proportion and extent of the situations in the US and Europe. We examine possible reasons for the difference, and develop hypotheses that this prevailing good bee health could be due to: (1) the management of generally unselected bees with a certain natural resistance to diseases (tropical regions) or the selection of disease resistant bees (temperate regions); (2) a lower proportion of cropland over the total land area, resulting in more abundant or higher-quality pollen resources for bees; (3) the generally small-scale, low-income and little subsidized agriculture, and concomitant lower use of insecticides compared to industrialized countries. These general parameters may act synergistically, resulting in a large number of configurations across the tremendous ecological, social and economic diversity of Latin America. We suggest that the health of honey bees in Latin America may be ultimately due to the practices of low-income agriculture and beekeeping in the region, leading to more sustainable conditions for the bees. However the increasing trend of land use intensification in some parts of Latin America could lead to declines in honey bee health and population size.

EU ban puts spotlight on complex effects of neonicotinoids

Bees brought to their knees: microbes affecting honey bee health

Beekeepers around the world have been reporting the ongoing weakening of honeybee health and subsequently the increasing colony losses since 1990. However, it was not until the abrupt emergence of colony collapse disorder (CCD) in the 2000s that has raised the concern of losing this important perennial pollinator. In this report, we provide a summary of the sub-lethal effects of pesticides, in particular of neonicotinoids, on pollinators’ health from papers published in peer-review journals. We have identified peer-review papers that are relevant to examine the effects of sub-lethal pesticide exposures on the health of honeybees (Apis mellifera), bumblebees (Bombus terrestris), and other bees from a literature search on PubMed and Google Scholar using the following combined keywords of “pollinators,” “honeybee,” “bees,” “pesticides,” or “neonicotinoids,” and from a cross-reference check of a report made available by the European Parliament in preparation to fulfill their regulatory mandate on the issue of protecting pollinators among their membership nations. The weight-of-evidence of this review clearly demonstrated bees’ susceptibility to insecticides, in particular to neonicotinoids, and the synergistic effects to diseases that are commonly present in bee colonies. One important aspect of assessing and managing the risks posed by neonicotinoids to bees is the chronic effects induced by exposures at the sub-lethal levels. More than 90% of literature published after 2009 directly or indirectly demonstrated the adverse health effects associated with sub-lethal exposure to neonicotinoids, including abnormal foraging activities, impaired brood development, neurological or cognitive effects, and colony collapse disorder.

Apiculture has developed into an important industry in India as honey and bee-wax have become common products. Recently, a sharp decline in population of honey bees has been observed in Kerala. Although the bees are susceptible to diseases and attacked by natural enemies like wasps, ants and wax moth, constant vigilance on the part of the bee keepers can overcome these adverse conditions. The present plunge in population (< 0.01) was not due to these reasons. It was caused by man due to unscientific proliferation of towers and mobile phones. Key words: Electromagnetic radiation, apiculture, colony collapse disorder. See: Notice of Retraction

The honey bee (Apis mellifera) is a domestic insect of high value to human societies, as a crop pollinator in agriculture and a model animal in scientific research. The honey bee, however, has experienced massive mortality worldwide due to the phenomenon Colony Collapse Disorder (CCD), resulting in alarming prospects for crop failure in Europe and the USA. The reasons for CCD are complex and much debated, but several honey bee pathogens are believed to be involved. Paratransgenesis is a Trojan horse strategy, where endogenous microorganisms are used to express effector molecules that antagonise pathogen development. For use in honey bees, paratransgenesis must rely on a set of criteria that the candidate paratransgenic microorganism must fulfil in order to obtain a successful outcome: (1) the candidate must be genetically modifiable to express effector molecules; (2) the modified organism should have no adverse effects on honey bee health upon reintroduction; and (3) it must survive together with other non-pathogenic bee-associated microorganisms. Lactic acid bacteria (LAB) are common gut bacteria in vertebrates and invertebrates, and some have naturally beneficial properties in their host. In the present work we aimed to find a potential paratransgenic candidate within this bacterial group for use in honey bees. Among isolated LAB associated with bee gut microbiota, we found the fructophilic Lactobacillus kunkeei to be the most predominant species during foraging seasons. Four genetically different strains of L. kunkeei were selected for further assessment. We demonstrated (1) that L. kunkeei is transformable; (2) that the transformed cells had no obvious adverse effect on honey bee survival; and (3) that transformed cells survived well in the gut environment of bees upon reintroduction. Our study demonstrates that L. kunkeei fulfils the three criteria for paratransgenesis and can be a suitable candidate for further research on this strategy in honey bees.

The ongoing decline of honey bee health worldwide is a serious economic and ecological concern. One major contributor to the decline are pathogens, including several honey bee viruses. However, information is limited on the biology of bee viruses and molecular interactions with their hosts. An experimental protocol to test these systems was developed, using injections of Israeli Acute Paralysis Virus (IAPV) into honey bee pupae reared ex-situ under laboratory conditions. The infected pupae developed pronounced but variable patterns of disease. Symptoms varied from complete cessation of development with no visual evidence of disease to rapid darkening of a part or the entire body. Considerable differences in IAPV titer dynamics were observed, suggesting significant variation in resistance to IAPV among and possibly within honey bee colonies. Thus, selective breeding for virus resistance should be possible. Gene expression analyses of three separate experiments suggest IAPV disruption of transcriptional homeostasis of several fundamental cellular functions, including an up-regulation of the ribosomal biogenesis pathway. These results provide first insights into the mechanisms of IAPV pathogenicity. They mirror a transcriptional survey of honey bees afflicted with Colony Collapse Disorder and thus support the hypothesis that viruses play a critical role in declining honey bee health.

The Western honey bee, Apis mellifera plays a crucial role as a pollinator worldwide. Except the wide number of commercial crops, honey bees pollinate many wild plants, some of which are threatened with extinction and are valuable genetic resource. Although during the last few years honey bee populations are steady and increasing in numbers with some fluctuation, there are a number of threats responsible for honey bee health and survival. As key factors for this are pointing out poor nutrition, sublethal insecticide exposure, and biotic stressors, including diseases and parasites. The decline of honey bee populations negatively affects not only many commercial crop and flowering plants, but also reduces honey bee products such as honey, bee pollen, propolis, bee venom, royal jelly and beeswax etc., many of them with significant role in human health benefits. Many hypotheses have been put forward in an attempt to explain these losses, but so far no indisputable factor has been identified responsible as the main driver of bee decline. Thus, it is necessary to urgently take measures to protect and preserve the honey bee by identifying and neutralizing the most significant causes leading to this phenomenon. Conservation methods are in place to protect A. mellifera and honey bee populations in a large part of the world. However, the survey also reveals the disparity in resources and information dedicated between honey bees and all other pollinators.