The Honey Bee Apis mellifera: An Insect at the Interface between Human and Ecosystem Health

De novo genome assemblies of the dwarf honey bee subgenus Micrapis : Apis andreniformis and Apis florea

The Micrapis subgenus, which includes the black dwarf honey bee ( Apis andreniformis ) and the red dwarf honey bee ( Apis florea ), remains underrepresented in genomic studies despite its ecological significance. Here, we present high-quality de novo genome assemblies for both species, generated using a hybrid sequencing approach combining Oxford Nanopore Technologies (ONT) long reads with Illumina short reads. The final assemblies are highly contiguous, with contig N50 values of 5.0 Mb ( A. andreniformis ) and 4.3 Mb ( A. florea ), representing a major improvement over the previously published A. florea genome. Genome completeness assessments indicate high quality, with BUSCO scores exceeding 98.5% and k-mer analyses supporting base-level accuracy. Repeat annotation revealed a relatively low repetitive sequence content (∼6%), consistent with other Apis species. Using RNA sequencing data, we annotated 12,232 genes for A. andreniformis and 12,597 genes for A. florea , with >97% completeness in predicted proteomes. These genome assemblies provide a valuable resource for comparative and functional genomic studies, offering new insights into the genetic basis of dwarf honey bee adaptations.

The use of honey bees (Apis mellifera L.) to monitor airborne particulate matter and assess health effects on pollinators

The honey bee Apis mellifera has long been recognized as an ideal bioindicator for environmental pollution. These insects are exposed to pollutants during their foraging activities, making them effective samplers of environmental contaminants, including heavy metals, pesticides, radionuclides, and volatile organic compounds. Recently, it has been demonstrated that honey bees can be a valuable tool for monitoring and studying airborne PM pollution, a complex mixture of particles suspended in the air, known to have detrimental effects on human health. Airborne particles attached to the bees can be characterised for their morphology, size, and chemical composition using a scanning electron microscopy coupled with X-ray spectroscopy, thus providing key information on the emission sources of the particles, their environmental fate, and the potential to elicit inflammatory injury, oxidative damage, and other health effects in living organisms. Here, we present a comprehensive summary of the studies involving the use of honey bees to monitor airborne PM, including the limits of this approach and possible perspectives. The use of honey bees as a model organism for ecotoxicological studies involving pollutant PM is also presented and discussed, further highlighting the role of the bees as a cornerstone of human, animal, and environmental health, according to the principles of the "One Health" approach.

Landfill fire impact on bee health: beneficial effect of dietary supplementation with medicinal plants and probiotics in reducing oxidative stress and metal accumulation

The honey bee is an important pollinator insect susceptible to environmental contaminants. We investigated the effects of a waste fire event on elemental content, oxidative stress, and metabolic response in bees fed different nutrients (probiotics, Quassia amara, and placebo). The level of the elements was also investigated in honey and beeswax. Our data show a general increase in elemental concentrations in all bee groups after the event; however, the administration of probiotics and Quassia amara help fight oxidative stress in bees. Significantly lower concentrations of Ni, S, and U for honey in the probiotic group and a general and significant decrease in elemental concentrations for beeswax in the probiotic group and Li in the Quassia amara group were observed after the fire waste event. The comparison of the metabolic profiles through pre- and post-event PCA analyses showed that bees treated with different feeds react differently to the environmental event. The greatest differences in metabolic profiles are observed between the placebo-fed bees compared to the others. This study can help to understand how some stress factors can affect the health of bees and to take measures to protect these precious insects.

Mitigating pesticide risk on bee pollinators and angiosperm biodiversity in the Ndop wetlands: A conservation approach

This study aimed to assess the risk of pesticides on bee pollinators and propose strategies to conserve entomophilous angiosperm species in the Ndop wetlands. Results showed that the applied pesticide doses were often excessive, increasing the exposure toxicity ratios (ETR). Among the pesticides, insecticides posed the highest risk to bee pollinators, with Emamectin benzoate (ETR=591.4) presenting the highest risk, followed by imidacloprid (ETR=517.5), fipronil (ETR=496.4), chlorpyrifos (ETR=240.7), and cypermethrin (ETR=131). Lambda-cyhalothrin (ETR=50.53) posed a possible risk. The study found that imidacloprid, fipronil, and chlorpyrifos posed definite risks through dietary exposure, while Emamectin benzoate, fipronil, and cypermethrin posed risks through direct contact. Approximately 46.03 % of angiosperms are anemophilous while 53 % are entomophilous with bee pollinators facilitating the pollination of nearly 90 % of the entomophilous species. To mitigate pesticide risks and for conservation purposes, farmers should refrain from applying pesticides during blooming and peak pollinator activity times, particularly midday.

Perspectives on terahertz honey bee sensing

Terahertz (THz) technology provides precise monitoring capabilities in dynamic environments, offering unique insights into insect habitats. Our study focuses on environmental monitoring of European honey bees (Apis mellifera) through a combination of measurements and simulations. Initially, the dielectric material properties of honey bee body parts are characterized across the spectral range of 1-500 GHz to collect heterogeneous empirical data. To extend the study, honey bee mockups made from polyamide 12 (PA12) and epoxy resin are employed and validated as effective substitutes for real bees through comparative scattering analyses. The research further explores radar cross-section (RCS), imaging, and spectral properties using advanced THz technologies, including resonant tunneling diodes (RTDs) operating at 250 GHz and THz time-domain spectroscopy (THz-TDS) for frequencies exceeding 250 GHz. High-resolution imaging, utilizing a 450 GHz bandwidth, captures intricate anatomical features of both real and 3D-printed bees, showcasing the potential of THz technology for detailed environmental monitoring. Finally, simulations at 300 GHz assess the dosimetry and feasibility of non-invasive, continuous monitoring approaches based on the heterogeneous honey bee model.

Environmental concentrations of TCEP and TDCIPP induce dysbiosis of gut microbiotal and metabolism in the honeybee (Apis mellifera L.)

Organophosphorus flame retardants (OPFRs) have emerged as significant global pollutants, yet their harmful effects on pollinating insects remain largely unexplored. This study explored the toxicological effects of tri(2-chloroethyl) phosphate (TCEP) and tri(1,3-dichloro-2-propyl) phosphate (TDCIPP) on the gut microbiota and metabolic pathways of honeybees (Apis mellifera L.). Exposure to TCEP led to a 35 % reduction in intestinal wall thickness and significantly suppressed the expression of pyrimidine metabolism-associated enzymes, including CAD, DHODH, and ODCase (p < 0.05). In contrast, TDCIPP exposure increased the relative abundance of Snodgrassella and Lactobacillus by 40 % and 25 %, respectively, while exerting more extensive toxicity by disrupting nucleotide metabolism, oxidative stress responses, and microbial diversity. Histological assessments revealed that both chemicals compromised intestinal wall integrity and induced crypt loss in the midgut epithelium. Multi-omics analyses underscored distinct toxicity mechanisms: TCEP primarily inhibited pyrimidine biosynthesis, impairing nucleotide synthesis and DNA repair processes, whereas TDCIPP caused broader metabolic disturbances, likely attributed to its greater hydrophobicity. Notably, the enhanced prevalence of certain microbial taxa suggests potential microbial adaptations to TDCIPP-induced stress. This comparative analysis highlighted the detrimental effects of TCEP and TDCIPP on gut health and metabolism, critical factors for honeybee survival and ecological function. These findings underscored the urgent need for further investigation into the ecological hazards posed by OPFRs and provided a basis for developing mitigation strategies to address the impacts of persistent organic pollutants (POPs) on pollinators.

Forecasting the Impact of Climate Change on Apis dorsata (Fabricius, 1793) Habitat and Distribution in Pakistan

Climate change has led to global biodiversity loss, severely impacting all species, including essential pollinators like bees, which are highly sensitive to environmental changes. Like other bee species, A. dorsata is also not immune to climate change. This study evaluated the habitat suitability of A. dorsata under climate change in Pakistan by utilizing two years of occurrence and distribution data to develop a Maximum Entropy (MaxEnt) model for forecasting current and future habitat distribution. Future habitat projections for 2050 and 2070 were based on two shared socioeconomic pathways (SSP245 and SSP585) using the CNRM-CM6-1 and EPI-ESM1-2-HR-1 global circulation models. Eight bioclimatic variables (Bio1, Bio4, Bio5, Bio8, Bio10, Bio12, Bio18, and Bio19) were selected for modeling, and among the selected variables, the mean temperature of the wettest quarter (Bio8) and precipitation of the warmest quarter (Bio18) showed major contributions to the model building and strongest influence on habitat of A. dorsata. The model estimated 23% of our study area as a suitable habitat for A. dorsata under current climatic conditions, comprising 150,975 km2 of moderately suitable and 49,792 km2 of highly suitable regions. For future climatic scenarios, our model projected significant habitat loss for A. dorsata with a shrinkage and shift towards northern, higher-altitude regions, particularly in Khyber Pakhtunkhwa and the Himalayan foothills. Habitat projections under the extreme climatic scenario (SSP585) are particularly alarming, indicating a substantial loss of the suitable habitat for the A. dorsata of 40% under CNRM-CM6-1 and 79% for EPI-ESM1-2-HR-1 for the 2070 time period. This study emphasizes the critical need for conservation efforts to protect A. dorsata and highlights the species' role in pollination and supporting the apiculture industry in Pakistan.

Gut Microbiome Diversity in European Honeybees (Apis mellifera L.) from La Union, Northern Luzon, Philippines

Insects often rely on symbiotic bacteria and fungi for various physiological processes, developmental stages, and defenses against parasites and diseases. Despite their significance, the associations between bacterial and fungal symbionts in Apis mellifera are not well studied, particularly in the Philippines. In this study, we collected A. mellifera from two different sites in the Municipality of Bacnotan, La Union, Philippines. A gut microbiome analysis was conducted using next-generation sequencing with the Illumina MiSeq platform. Bacterial and fungal community compositions were assessed using 16S rRNA and ITS gene sequences, respectively. Our findings confirm that adult worker bees of A. mellifera from the two locations possess distinct but comparably proportioned bacterial and fungal microbiomes. Key bacterial symbionts, including Lactobacillus, Bombilactobacillus, Bifidobacterium, Gilliamella, Snodgrassella, and Frischella, were identified. The fungal community was dominated by the yeasts Zygosaccharomyces and Priceomyces. Using the ENZYME nomenclature database and PICRUSt2 software version 2.5.2, a predicted functional enzyme analysis revealed the presence of β-glucosidase, catalase, glucose-6-phosphate dehydrogenase, glutathione transferase, and superoxide dismutase, which are involved in host defense, carbohydrate metabolism, and energy support. Additionally, we identified notable bacterial enzymes, including acetyl-CoA carboxylase and AMPs nucleosidase. Interestingly, the key bee symbionts were observed to have a negative correlation with other microbiota. These results provide a detailed characterization of the gut microbiota associated with A. mellifera in the Philippines and lay a foundation for further metagenomic studies of microbiomes in native or indigenous bee species in the region.

Numerical dosimetry of specific absorption rate of insects exposed to far-field radiofrequency electromagnetic fields

PURPOSE

This paper reports a study of electromagnetic field (EMF) exposure of several adult insects: a ladybug, a honey bee worker, a wasp, and a mantis at frequencies ranging from 2.5 to 100 GHz. The purpose was to estimate the specific absorption rate (SAR) in insect tissues, including the brain, in order to predict the possible biological effects caused by EMF energy absorption.

METHOD

Numerical dosimetry was executed using the finite-difference time-domain (FDTD) method. Insects were modeled as 3-tissue heterogeneous dielectric objects, including the cuticle, the inner tissue, and the brain tissue. The EMF source was modeled as sinusoidal plane waves at a single frequency (far-field exposure).

RESULTS

The whole-body averaged, tissue averaged, and 1 milligram SAR values were determined in insects for all considered frequencies for 10 different incident plane waves. SAR values were normalized to the incident power density of 1 mW/cm2. Maximal EMF absorption in the inner and brain tissues was observed at 6, 12, and 25 GHz for the considered insects, except the brain tissue of a ladybug (max at 60 GHz).

CONCLUSION

The paper presented the first estimation of the SAR for multiple insects over a wide range of RF frequencies using 3-tissue heterogenous insect 3D models created for this specific research. The selection of tissues' dielectric properties was validated. The obtained results showed that EMF energy absorption in insects highly depends on frequency, polarization, and insect morphology.

Examination of intestinal microbiota abundance of honey bees supplemented and unsupplemented with probiotic bacteria by QPCR

The aim of this study is to compare the bacterial load in the guts of honey bees supported and unsupplemented with probiotic supplements. To investigate the effects of a commercial bee probiotic containing different Lactobacillus species and different spice extracts on the composition of the gut microbiota of honey bees, QPCR counts of Lactobacillus spp. and Firmicutes phylum gene copies in gut mixtures from 12 different bee groups with and without probiotic supplementation were performed. There was a significant difference between the levels of Lactobacillus spp. in the guts of both groups. When Lactobacillus spp. levels in the guts of honey bees not given probiotics were compared to the Lactobacillus spp. levels in the guts of honey bees given probiotics, it was determined that there was an approximately 5.5-fold difference. However, it was observed that there was no significant difference in the Firmicutes load in the bee guts of both groups. These findings show that the applied probiotic formulation significantly affects the intestinal microbiome of healthy individuals and provides a proportional change in microbial abundance, especially in terms of Lactobacillus spp.

The Influence of the Chemical Composition of Beeswax Foundation Sheets on Their Acceptability by the Bee's Colony

Beeswax is one of the most important products for the well-being of bee colonies. The wax glands of young worker bees produce beeswax, which serves as a building material for honeycomb construction. Beekeepers using hives with mobile frames mainly utilize local beeswax to make foundations. Any paraffin addition represents adulteration, resulting in a high degree of contamination. During the preparation of re-used beeswax, losses during the process may instigate producers to add cheaper, wax-like substances like paraffin and tallow. This article presents a systematic investigation of the quality of beeswax foundation from six major producers in Vojvodina, Serbia, by applying the classic analytical procedure for the determination of selected physicochemical parameters and instrumental gas chromatography coupled with mass spectrometry (GC-MS) and Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy techniques. FTIR-ATR detected possible paraffin and beef tallow in 72 foundation sheet samples. This technique was complemented with GC-MS. This analysis revealed that paraffin content ranged between 19.75 and 85.68%, while no tallow was detected over the two-year period. Two sheets from each manufacturer were placed into wired Langstroth-Ruth frames and placed in beehives. The construction, based on built cells, was monitored every 24 h. Evaluating newly inserted sheets proved that without quality nectar, there is no intensive building, regardless of adulteration.

Sublethal Effects Induced by a Cyflumetofen Formulation on Honeybee Apis mellifera L. Workers: Assessment of Midgut, Hypopharyngeal Glands, and Fat Body Integrity

Worldwide, both cultivated and wild plants are pollinated by the honey bee, Apis mellifera. Bee numbers are declining as a result of a variety of factors, including increased pesticide use. Cyflumetofen controls pest mites in some plantations pollinated by bees, which may be contaminated with residual sublethal concentrations of this pesticide, in nectar and pollen. We evaluated the effects of a sublethal concentration of a cyflumetofen formulation on the midgut, hypopharyngeal gland, and fat body of A. mellifera workers orally exposed for 72 h or 10 days. The midgut epithelium of treated bees presented digestive cells with cytoplasm vacuoles and some cell fragmentation, indicating autophagy and cell death. After being exposed to the cyflumetofen formulation for 72 h, the midgut showed a higher injury rate than the control bees, but after 10 days, the organs had recovered. In the hypopharyngeal gland of treated bees, the end apparatus was filled with secretion, suggesting that the acaricide interferes with the secretory regulation of this gland. Histochemical tests revealed differences in the treated bees in both exposure periods in the midgut and hypopharyngeal glands. The acaricide caused cytotoxic effects on the midgut digestive cells, with apical protrusions, plasma membrane rupture, and several vacuoles in the cytoplasm, features of cell degeneration. In the hypopharyngeal glands of the treated bees, the secretory cells presented small electron-dense and large electron-lucent secretory granules. The fat body cells had no changes in comparison with the control bees. In conclusion, the cyflumetofen formulation at sublethal concentrations causes damage to the midgut and the hypopharyngeal glands of honey bee, which may compromise the functions of these organs and colony fitness. Environ Toxicol Chem 2024;43:2455-2465. © 2024 SETAC.

From molecules to organisms: A multi-level approach shows negative effects of trace elements from sewage sludge used as soil improver on honeybees

The use of sewage sludge as a soil improver has been promoted in agroecosystems. However, sludges can contain toxic trace elements because of suboptimal wastewater treatment. Nonetheless, field studies investigating the negative effects of these practices on pollinators are lacking. We collected honeybees from an area where sewage sludge use is widespread, and one where it is precluded. Trace elements in soils and bees were quantified. Cadmium, chromium, lead, mercury, and nickel were investigated because they were the least correlated elements to each other and are known to be toxic. Their levels were related to oxidative stress and energy biomarkers, midgut epithelial health, body size and wing asymmetry of honeybees. We found increased carbohydrate content in sites with higher cadmium levels, increased histological damage to the midgut epithelium in the sewage sludge area, and the presence of dark spherites in the epithelium of bees collected from the sites with the highest lead levels. Finally, we found that honeybees with the highest lead content were smaller, and that wing fluctuating asymmetry increased in sites with increasing levels of mercury. To the best of our knowledge, this is the first comprehensive study of the concentration and effects on honeybees of trace elements potentially deriving from soil amendment practices.

Enantioselective toxicity of the neonicotinoid dinotefuran on honeybee (Apis mellifera) larvae

The threat of neonicotinoids to insect pollinators, particularly honeybees (Apis mellifera), is a global concern, but the risk of chiral neonicotinoids to insect larvae remains poorly understood. In the current study, we evaluated the acute and chronic toxicity of dinotefuran enantiomers to honeybee larvae in vitro and explored the mechanism of toxicity. The results showed that the acute median lethal dose (LD50) of S-dinotefuran to honeybee larvae was 30.0 μg/larva after oral exposure for 72 h, which was more toxic than rac-dinotefuran (92.7 μg/larva) and R-dinotefuran (183.6 μg/larva). Although the acute toxicity of the three forms of dinotefuran to larvae was lower than that to adults, chronic exposure significantly reduced larval survival, larval weight, and weight of newly emerged adults. Analysis of gene expression and hormone titer indicated that dinotefuran affects larval growth and development by interfering with nutrient digestion and absorption and the molting system. Analysis of hemolymph metabolome further revealed that disturbances in the neuroactive ligand-receptor interaction pathway and energy metabolism are the key mechanisms of dinotefuran toxicity to bee larvae. In addition, melatonin and vitellogenin are used by larvae to cope with dinotefuran-induced oxidative stress. Our results contribute to a comprehensive understanding of dinotefuran damage to bees and provide new insights into the mechanism of enantioselective toxicity of insecticides to insect larvae.

Antioxidant Capacity, Phytochemicals, Minerals, and Chemical Pollutants in Worker Honey Bee (Apis mellifera L.) Broods from Northern Thailand: A Safe and Sustainable Food Source

Honey bee brood (HBB) (Apis mellifera L.), a traditional protein source, has been studied for its nutritional value, but bio-functional properties and safety concerns have not been verified. This study examined the Antioxidant capacity, phytochemicals, minerals, and chemical pollutants in worker broods from several apiaries in Northern Thailand. HBB samples were lyophilized to evaluate antioxidant capacity using ABTS, DPPH, and FRAP assays, tests with water, and 70% ethanol extracts. Phytochemicals were identified using LC-QTOF-MS; pollutants were analyzed chromatographically, and minerals were determined using ICP-OES. The results showed that the evaluated antioxidant capacity of the ethanol extracts included DPPH 2.04-3.37 mg/mL, ABTS 21.22-33.91 mg/mL, and FRAP 50.07-104.15 mg AAE/100 g dry weight. Water extracts had outstanding antioxidant activities except for ABTS, with DPPH 10.67-84.97 mg/mL, ABTS 9.25-13.54 mg/mL, and FRAP 57.66-177.32 mgAAE/100 g dry weight. Total phenolics and flavonoids in ethanol extracts ranged from 488.95-508.87 GAE/100 g to 4.7-12.98 mg QE/g dry weight, respectively. Thirteen phytochemicals were detected and contained adequate mineral contents in the HBBs from different locations found, which were K, Ca, Mg, and Na, and no heavy metals or pollutants exceeded safe levels. These results imply that HBB from different apiaries in Northern Thailand is a nutritious food source with considerable antioxidants and a safe and sustainable food source.

Toxic effects of acaricide fenazaquin on development, hemolymph metabolome, and gut microbiome of honeybee (Apis mellifera) larvae

Fenazaquin, a potent insecticide widely used to control phytophagous mites, has recently emerged as a potential solution for managing Varroa destructor mites in honeybees. However, the comprehensive impact of fenazaquin on honeybee health remains insufficiently understood. Our current study investigated the acute and chronic toxicity of fenazaquin to honeybee larvae, along with its influence on larval hemolymph metabolism and gut microbiota. Results showed that the acute median lethal dose (LD50) of fenazaquin for honeybee larvae was 1.786 μg/larva, and the chronic LD50 was 1.213 μg/larva. Although chronic exposure to low doses of fenazaquin exhibited no significant effect on larval development, increasing doses of fenazaquin resulted in significant increases in larval mortality, developmental time, and deformity rates. At the metabolic level, high doses of fenazaquin inhibited nucleotide, purine, and lipid metabolism pathways in the larval hemolymph, leading to energy metabolism disorders and physiological dysfunction. Furthermore, high doses of fenazaquin reduced gut microbial diversity and abundance, characterized by decreased relative abundance of functional gut bacterium Lactobacillus kunkeei and increased pathogenic bacterium Melissococcus plutonius. The disrupted gut microbiota, combined with the observed gut tissue damage, could potentially impair food digestion and nutrient absorption in the larvae. Our results provide valuable insights into the complex and diverse effects of fenazaquin on honeybee larvae, establishing an important theoretical basis for applying fenazaquin in beekeeping.

Current honey bee stressor investigations and mitigation methods in the United States and Canada

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.

The buzz about honey-based biosurveys

Approximately 1.8 million metric tonnes of honey are produced globally every year. The key source behind this output, the honey bee (Apis mellifera), works tirelessly to create the delicious condiment that is consumed worldwide. The honey that finds its way into jars on store shelves contains a myriad of information about its biogeographical origins, such as the bees that produced it, the botanical constituents, and traces of other organisms or pathogens that have come in contact with the product or its producer. With the ongoing threat of honey bee decline and overall global biodiversity loss, access to ecological information has become an key factor in preventing the loss of species. This review delves into the various molecular techniques developed to characterize the collective DNA harnessed within honey samples, and how it can be used to elucidate the ecological interactions between honey bees and the environment. We also explore how these DNA-based methods can be used for large-scale biogeographical studies through the environmental DNA collected by foraging honey bees. Further development of these techniques can assist in the conservation of biodiversity by detecting ecosystem perturbations, with the potential to be expanded towards other critical flying pollinators.

A systemic study of cyenopyrafen in strawberry cultivation system: Efficacy, residue behavior, and impact on honeybees (Apis mellifera L.)

The pesticide application method is one of the important factors affecting its effectiveness and residues, and the risk of pesticides to non-target organisms. To elucidate the effect of application methods on the efficacy and residue of cyenopyrafen, and the toxic effects on pollinators honeybees in strawberry cultivation, the efficacy and residual behavior of cyenopyrafen were investigated using foliar spray and backward leaf spray in field trials. The results showed that the initial deposition of cyenopyrafen using backward leaf spray on target leaves reached 5.06-9.81 mg/kg at the dose of 67.5-101.25 g a.i./ha, which was higher than that using foliar spray (2.62-3.71 mg/kg). The half-lives of cyenopyrafen in leaves for foliar and backward leaf spray was 2.3-3.3 and 5.3-5.9 d, respectively. The residues (10 d) of cyenopyrafen in leaves after backward leaf spray was 1.41-3.02 mg/kg, which was higher than that after foliar spraying (0.25-0.37 mg/kg). It is the main reason for the better efficacy after backward leaf spray. However, the residues (10 d) in strawberry after backward leaf spray and foliar spray was 0.04-0.10 and < 0.01 mg/kg, which were well below the established maximum residue levels of cyenopyrafen in Japan and South Korea for food safety. To further investigate the effects of cyenopyrafen residues after backward leaf spray application on pollinator honeybees, sublethal effects of cyenopyrafen on honeybees were studied. The results indicated a significant inhibition in the detoxification metabolic enzymes of honeybees under continuous exposure of cyenopyrafen (0.54 and 5.4 mg/L) over 8 d. The cyenopyrafen exposure also alters the composition of honeybee gut microbiota, such as increasing the relative abundance of Rhizobiales and decreasing the relative abundance of Acetobacterales. The comprehensive data on cyenopyrafen provide basic theoretical for environmental and ecological risk assessment, while backward leaf spray proved to be effective and safe for strawberry cultivation.

Opportunities and challenges in using NIH's Dietary Supplement Label Database for research on non-nutrient ingredients: Use case for ingredients in honeybee products

Background

Non-nutrient bioactive ingredients of foods such as bee products are often of interest in preclinical and clinical research to explore their possible beneficial effects. The National Institute of Health's Dietary Supplement Label Database (DSLD) contains over 165,000 labels of dietary supplements marketed in the United States of America (US), including declarations on labels for many of these ingredients, including those in honeybee products which have been used in foods and traditional medicines for centuries worldwide and are now also appearing in dietary supplements.

Methods

This article presents a use case for honeybee products that describes and tests the utility of the DSLD and other databases available in the US as research tools for identifying and quantifying the prevalence of such ingredients.. It focuses on the limitations to the information on product composition in these databases and describes how to code the ingredients using the LanguaL™ or FoodEx2 description and classification systems and the strengths and limitations of information on honeybee product ingredients, including propolis, bee pollen, royal jelly, beeswax, and bee venom.

Results and Conclusions

Codes for the ingredients are provided for identifying their presence in LanguaL™ or FoodEx2 ontologies used in Europe and elsewhere. The prevalence of dietary supplement products containing these ingredients in DSLD and on the US market is low compared to some other products and ingredients. Unfortunately label declarations in DSLD do not provide quantitative information and so the data can be used only to screen for their presence, but cannot be used for quantitative exposure estimates by researchers and regulators .

Nectar Characteristics and Honey Production Potential of Five Rapeseed Cultivars and Two Wildflower Species in South Korea

The growing beekeeping industry in South Korea has led to the establishment of new honey plant complexes. However, studies on honey production from each species are limited. This study aimed to assess the honey production potential of various Brassica napus cultivars and two wildflower species. The nectar characteristics of B. napus varied significantly among the cultivars. Absolute sugar concentrations differed among the cultivars, but sugar composition ratios were similar. In contrast, the amino acid content remained relatively uniform regarding percentage values, irrespective of the absolute concentrations. Estimations of honey potential production per hectare (kg/ha) resulted in the following ranking among cultivars: 'JM7003' (107.1) > 'YS' (73.0) > 'JM7001' (63.7) > 'TL' (52.7) > 'TM' (42.4). The nectar volume of Pseudolysimachion rotundum var. subintegrum and Leonurus japonicus increased during the flowering stage. P. rotundum var. subintegrum was sucrose-rich and L. japonicus was sucrose-dominant. Both species predominantly contained phenylalanine, P. rotundum var. subintegrum had glutamine as the second most abundant amino acid, and L. japonicus had tyrosine. The honey production potential was 152.4 kg/ha for P. rotundum var. subintegrum and 151.3 kg/ha for L. japonicus. These findings provide a basis for identifying food resources for pollinators and selecting plant species to establish honey plant complexes.

Potential application of bee products in food industry: An exploratory review

Over the past eight years, bee products such as wax, honey, propolis, and pollen have generated intense curiosity about their potential food uses; to explore these possibilities, this review examines the nutritional benefits and notable characteristics of each product related to the food industry. While all offer distinct advantages, there are challenges to overcome, including the risk of honey contamination. Indeed, honey has excellent potential as a healthier alternative to sugar, while propolis's remarkable antibacterial and antioxidant properties can be enhanced through microencapsulation. Pollen is a versatile food with multiple applications in various products. In addition, the addition of beeswax to oleogels and its use as a coating demonstrate significant improvements in the quality and preservation of environmentally sustainable foods over time. This study demonstrates that bee products and apitherapy are essential for sustainable future food and innovative medical treatments.

Propolis and its therapeutic effects on renal diseases: A review

Propolis is produced by bees using a mixture of bees wax and saliva. It contains several bioactive compounds that mainly induce anti-oxidant and anti-inflammatory effects. In this review, we aimed to investigate the effects of propolis on kidney diseases. We used "Kidney", "Disease", "Propolis", "Renal", "Constituent", "Mechanism", "Infection", and other related keywords as the main keywords to search for works published before July 2023 in Google scholar, Scopus, and Pubmed databases. The search terms were selected according to Medical Subject Headings (MeSH). This review showed that propolis affects renal disorders with inflammatory and oxidative etiology due to its bioactive compounds, mainly flavonoids and polyphenols. There have been few studies on the effects of propolis on kidney diseases; nevertheless, the available studies are integrated in this review. Overall, propolis appears to be effective against several renal diseases through influencing mechanisms such as apoptosis, oxidative balance, and inflammation.

Investigating the effects of mesotrione/atrazine-based herbicide on honey bee foragers

A mixture of the herbicides mesotrione and atrazine (Calaris®) is a widely used herbicide in agriculture in several countries. However, the possible toxicological effects of this formulation on non-target organisms require investigation. In this study, the effects of acute oral exposure to Calaris® were evaluated in Apis mellifera foragers. The effect of seven different concentrations of Calaris® on survival and sucrose consumption was studied, while the recommended concentration for field use (FC) and its 10× dilution (0.1 FC) were used to assess overall locomotor activity, respiratory rate, flight, midgut morphology, oxidative and nitrosative stresses, and hemocyte counting. The exposure to FC or 0.1 FC decreased locomotor activity and induced damage to the midgut epithelium. Additionally, the two tested concentrations reduced superoxide dismutase activity, nitric oxide levels, and total hemocyte count. FC also increased malondialdehyde content and 0.1 FC increased respiratory rate and decreased the proportion of prohemocytes. Overall, our findings evidenced significant harmful effects on A. mellifera foragers resulting from the ingestion of the Calaris® herbicide.

Gut microbiome helps honeybee (Apis mellifera) resist the stress of toxic nectar plant (Bidens pilosa) exposure: Evidence for survival and immunity

Honeybee (Apis mellifera) ingestion of toxic nectar plants can threaten their health and survival. However, little is known about how to help honeybees mitigate the effects of toxic nectar plant poisoning. We exposed honeybees to different concentrations of Bidens pilosa flower extracts and found that B. pilosa exposure significantly reduced honeybee survival in a dose-dependent manner. By measuring changes in detoxification and antioxidant enzymes and the gut microbiome, we found that superoxide dismutase, glutathione-S-transferase and carboxylesterase activities were significantly activated with increasing concentrations of B. pilosa and that different concentrations of B. pilosa exposure changed the structure of the honeybee gut microbiome, causing a significant reduction in the abundance of Bartonella (p < 0.001) and an increase in Lactobacillus. Importantly, by using Germ-Free bees, we found that colonization by the gut microbes Bartonella apis and Apilactobacillus kunkeei (original classification as Lactobacillus kunkeei) significantly increased the resistance of honeybees to B. pilosa and significantly upregulated bee-associated immune genes. These results suggest that honeybee detoxification systems possess a level of resistance to the toxic nectar plant B. pilosa and that the gut microbes B. apis and A. kunkeei may augment resistance to B. pilosa stress by improving host immunity.

Screening of Entomopathogenic Fungal Culture Extracts with Honeybee Nosemosis Inhibitory Activity

This study aimed to select the most effective culture extracts for controlling honeybee nosemosis using 342 entomopathogenic fungi of 24 species from 18 genera. The germination inhibitory activity of the fungal culture extract on Nosema ceranae spores was evaluated using an in vitro germination assay method. Among 89 fungal culture extracts showing germination inhibitory activity of approximately 80% or more, 44 fungal culture extracts that maintained their inhibitory activity even at a concentration of 1% were selected. Finally, the honeybee nosemosis inhibitory activity was evaluated using the cultured extracts of five fungal isolates having a Nosema inhibitory activity of approximately 60% or more, even when the extract was removed after treatment. As a result, the proliferation of Nosema spores was reduced by all fungal culture extract treatments. However, only the treatment of the culture extracts from Paecilomyces marquandii 364 and Pochonia bulbillosa 60 showed a reduction in honeybee mortality due to nosemosis. In particular, the extracts of these two fungal isolates also increased the survival of honeybees.

Origin of non-exhaust PM in cities by individual analysis of particles collected by honey bees (Apis mellifera)

Urban areas present multiple challenges to scientists interested in unraveling the source, transport, and fate of airborne particulate matter (PM). Airborne PM consists of a heterogeneous mixture of particles with different sizes, morphologies, and chemical compositions. However, standard air quality stations only detect the mass concentration of PM mixtures with aerodynamic diameters ≤10 μm (PM₁₀) and/or ≤ 2.5 μm (PM_2.5). During honey bee foraging flights, airborne PM up to 10 μm in size attaches to their bodies, making them suitable for collecting spatiotemporal data on airborne PM. The individual particulate chemistry of this PM can be assessed using scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy on a sub-micrometer scale, allowing accurate identification and classification of the particles. Herein, we analyzed the PM fractions of 10-2.5 μm, 2.5-1 μm, and below 1 μm in average geometric diameter collected by bees from hives located in the city of Milan, Italy. Bees showed contamination by natural dust, originating from soil erosion and rock outcropping in the foraging area, and particles with recurrent heavy metal content, most likely attributed to vehicular braking systems and possibly tires (non-exhaust PM). Notably, approximately 80% of non-exhaust PM was ≤1 μm in size. This study provides a possible alternative strategy to apportion the finer fraction of PM in urban areas and determine citizens' exposure. Our findings may also prompt decision-makers to issue policy addressal for non-exhaust pollution, especially for the ongoing restructuring of European regulations on mobility and the shift toward electric vehicles whose contribution to PM pollution is debated.

Bioinsecticide spinosad poses multiple harmful effects on foragers of Apis mellifera

There are multifactorial causes for the recent decline in bee populations, which has resulted in compromised pollination and reduced biodiversity. Bees are considered one of the most important non-target insects affected by insecticides used in crop production. In the present study, we investigated the effects of acute oral exposure to spinosad on the survival, food consumption, flight behavior, respiration rate, activity of detoxification enzymes, total antioxidant capacity (TAC), brain morphology, and hemocyte count of Apis mellifera foragers. We tested six different concentrations of spinosad for the first two analyses, followed by LC₅₀ (7.7 mg L^-1) for other assays. Spinosad ingestion decreased survival and food consumption. Exposure to spinosad LC₅₀ reduced flight capacity, respiration rate, and superoxide dismutase activity. Furthermore, this concentration increased glutathione S-transferase activity and the TAC of the brain. Notably, exposure to LC₅₀ damaged mushroom bodies, reduced the total hemocyte count and granulocyte number, and increased the number of prohemocytes. These findings imply that the neurotoxin spinosad affects various crucial functions and tissues important for bee performance and that the toxic effects are complex and detrimental to individual homeostasis.

Evaluation of the effects of a honey‑based gel on blood redox biomarkers and the physiological profile of healthy adults: A pilot study

Honey is a natural product derived from the insect Apis mellifera. Approximately 200 different compounds are included, making it a complex mixture with antimicrobial, antioxidant, and antidiabetic activity. Flavonoids and phenolic acids contained in honey are associated with its antioxidant capacity via mechanisms such as hydrogen donation and metallic ion chelation, although the exact antioxidant mechanism remains unknown. The aim of the present study was to: i) Estimate the antioxidant activity of a natural honey-based gel, commercially available under the trade name of 'Bear Strength honey gel' and to ii) assess the physiological and redox adjustments obtained after its consumption in healthy adult participants. For this purpose, 20 healthy participants (10 men and 10 women) included in their habitual diet 70 g of the honey-based gel for 14 days in a row. Pre- and post-consumption, physiological [weight, height, body mass index, body fat, waist-to-hip ratio, resting heart rate and blood pressure (BP)] and hematological (complete blood count) data were evaluated, along with the levels of five redox biomarkers: Glutathione (GSH), catalase (CAT), total antioxidant capacity (TAC), protein carbonyls (PCARBS) and thiobarbituric reactive substances (TBARS). The results revealed that the honey-based gel decreased the diastolic and mean arterial BP, especially in women, without affecting the rest of the physiological and hematological variables. Regarding the changes observed in antioxidant status variables, GSH was increased both in the total and women's group, while TAC was increased in all groups post-consumption. No changes were detected in the levels of CAT. Regarding oxidative stress, a decrease in the levels of TBARS in the total and women's group, was observed. PCARBS levels were decreased post-consumption only in the women's group. In conclusion, the present study demonstrated the potential positive effects of a honey-based gel on BP and redox status of healthy adults in a sex-specific manner.

Amitraz and Its Metabolites: Oxidative Stress-Mediated Cytotoxicity in HepG2 Cells and Study of Their Stability and Characterization in Honey

The population decrease of bees that has been observed in recent years due to the Varroa destructor parasite may endanger the production of bee-products whose demand is on the rise. To minimize the negative effects caused by this parasite, the pesticide amitraz is commonly used by beekeepers. Based on these, the objectives of this work are to determine the toxic effects caused by amitraz and its metabolites in HepG2 cells, as well as its determination in honey samples and the study of its stability with different heat treatments commonly used in the honey industry and its relationship with the amount of 5-hydroxymethylfurfural (HMF) produced. Amitraz significantly decreased cell viability by MTT assay and total protein content (PC) assay, being more cytotoxic than its metabolites. Amitraz and its metabolites caused oxidative stress by Lipid Peroxidation (LPO) production and Reactive Oxygen Species (ROS) generation. Residues of amitraz and/or its metabolites were found in analyzed honey samples, with 2,4-Dimethylaniline (2,4-DMA) being the main metabolite confirmed by high-performance liquid chromatography-high resolution mass spectrometry (HPLC-QTOF HRMS). Amitraz and its metabolites resulted as unstable even at moderate heat treatments. Additionally, a positive correlation in terms of HMF concentration in samples and the severity of heat treatment was also observed. However, quantified amitraz and HMF were within the levels set in the regulation.

Determinants of Honey and Other Bee Products Use for Culinary, Cosmetic, and Medical Purposes

Bee products have been used for centuries for culinary, medicinal, and cosmetic purposes, and their properties are still a subject of research, which provide new arguments in favour of their use. The research aimed to determine the current state of use of bee products by Polish consumers and determine the ways and conditions of their use, with particular reference to the level of nutritional knowledge and health status. The survey was conducted using the CAWI (Computer-Assisted Web Interview) method on 487 respondents. It was found that honey is used mainly for culinary purposes and, to a lesser extent, for medicinal and cosmetic purposes. Other bee products are much less commonly used than honey-mainly beeswax and royal jelly for cosmetic purposes and propolis and bee pollen for medicinal purposes. Segments distinguished by the frequency of use of honey for particular purposes were differentiated by gender, age, income level, use of other bee products, and motivation to use them. Their differences were also found in terms of the level of nutritional knowledge and self-assessed health status-the highest ratings in both categories were indicated by representatives of the Honey users' segment, which consisted of people who use honey most frequently for cooking, cosmetic and medicinal purposes. Regression analysis additionally showed that higher levels of nutritional knowledge and better health status were associated with the use of honey to treat gastrointestinal ailments and with the use of propolis for medicinal purposes.

Propolis and Their Active Constituents for Chronic Diseases

Propolis is a mass of chemically diverse phytoconstituents with gummy textures that are naturally produced by honeybees upon collection of plant resins for utilization in various life processes in beehives. Since ancient times, propolis has been a unique traditional remedy globally utilized for several purposes, and it has secured value in pharmaceutical and nutraceutical areas in recent years. The chemical composition of propolis comprises diverse constituents and deviations in the precise composition of the honeybee species, plant source used for propolis production by bees, climate conditions and harvesting season. Over 300 molecular structures have been discovered from propolis, and important classes include phenolic acids, flavonoids, terpenoids, benzofurans, benzopyrene and chalcones. Propolis has also been reported to have diverse pharmacological activities, such as antidiabetic, anti-inflammatory, antioxidant, anticancer, immunomodulatory, antibacterial, antiviral, antifungal, and anticaries. As chronic diseases have risen as a global health threat, abundant research has been conducted to track propolis and its constituents as alternative therapies for chronic diseases. Several clinical trials have also revealed the potency of propolis and its constituents for preventing and curing some chronic diseases. This review explores the beneficial effect of propolis and its active constituents with credible mechanisms and computational studies on chronic diseases.

Probiotics as a promising prophylactic tool to reduce levels of toxic or potentially toxic elements in bees

Bees are precious living beings for our planet. Thanks to their essential service of pollination, these insects allow the maintenance of biodiversity and the variety and amount of food available. Unfortunately, we are observing an increasingly devastating reduction of bee families and other pollinating insects for factors related to human activities, environmental pollution, diseases and parasites, compromise of natural habitats, and climate change. We show that probiotics can protect bees from element pollution. We collected bees, beeswax, honey, pollen, and propolis directly from hives in a rural area of central Italy to investigate the content of 41 elements in control (not supplemented with probiotics) and experimental (supplemented with probiotics) groups. Our data show a significantly lower concentration of some elements (Ba, Be, Cd, Ce, Co, Cu, Pb, Sn, Tl, and U) in experimental bees than in control groups, indicating a possible beneficial effect of probiotics in reducing the absorption of chemicals. This study presents the first data on element levels after probiotics have been fed to bees and provides the basis for future research in several activities relating to the environment, agriculture, economy, territory, and medicine.

The negative effect of flumethrin stress on honey bee (Apis mellifera) worker from larvae to adults

Flumethrin is a highly effective acaricide, but its lipophilic characteristic has some negative effects, such as accumulation in bee hives and bee products. However, studies on the survival stress of honey bees subsequent to chronic flumethrin exposure are limited. To answer this question, a study was carried out on the stress to honey bee (Apis mellifera) workers from larvae to adults by chronic exposure to sublethal concentrations of flumethrin. Three flumethrin treatment groups (1, 0.1, 0.01 mg/L) and one control group (with no added flumethrin) were established and divided the worker larvae into four groups. Then, starting with 2-day-old larvae, larvae and subsequent emerged worker bees of the four groups were orally fed with the corresponding concentrations of flumethrin until all the adult worker bees died, respectively. When the concentration was at 0.01 mg/L of flumethrin, the lifespan of adult worker bees decreased, and a down-regulation of detoxification-related genes (CYP450,GSTS) was induced in 1-day-old pupae. When it is at 0.1 mg/L flumethrin, the lifespan of adult worker bees was again shortened, and down-regulation of memory-related genes (GluRA1, Nmdar1, Tyr1) in 1-day-old pupae and gene Tyr1 in 1-day-old worker bees, detoxification-related genes (CYP450,GSTS) in 1-day-old pupae, and immunity genes (Defensin1, Hymenoptaecin) in 7-day-old worker bees were observed. When the concentration is at 1 mg/L flumethrin, lighter birth weight of newly emerged honeybee was found and deficiencies in olfactory learning and memory were observed in 7-day-old worker bees. Memory-related genes (GluRA1, Nmdar1, Tyr1) were down-regulated in 1-day-old pupae and genes (Nmdar1,Tyr1)in 1-day-old worker bees, as were detoxification-related genes (CYP450,GSTS) in 1-day-old pupae and gene CPY450 in 7-day-old worker bees, and immune genes (Defensin1, Hymenoptaecin) in 7-day-old worker bees. There was no significant difference in pupal weight, capping rate, emergence rate, expression of immune-related genes of 1-day-old pupae, expression of immune-related genes and detoxification-related genes of 1-day-old worker bees, expression of memory-related genes and detoxification-related gene GSTS of 7-day-old worker bees. These data provide an ominous warning about the unintended consequences on apiaries, and underscore the need for careful control of flumethrin residues in bee hives.

The Insecticide Imidacloprid Decreases Nannotrigona Stingless Bee Survival and Food Consumption and Modulates the Expression of Detoxification and Immune-Related Genes

Stingless bees are ecologically and economically important species in the tropics and subtropics, but there has been little research on the characterization of detoxification systems and immune responses within them. This is critical for understanding their responses to, and defenses against, a variety of environmental stresses, including agrochemicals. Therefore, we studied the detoxification and immune responses of a stingless bee, Nanotrigona perilampoides, which is an important stingless bee that is widely distributed throughout Mexico, including urban areas, and has the potential to be used in commercial pollination. We first determined the LC50 of the neonicotinoid insecticide imidacloprid for foragers of N. perilampoides, then chronically exposed bees for 10 days to imidacloprid at two field-realistic concentrations, LC10 (0.45 ng/µL) or LC20 (0.74 ng/µL), which are respectively 2.7 and 1.3-fold lower than the residues of imidacloprid that have been found in honey (6 ng/g) in central Mexico. We found that exposing N. perilampoides stingless bees to imidacloprid at these concentrations markedly reduced bee survival and food consumption, revealing the great sensitivity of this stingless bee to the insecticide in comparison to honey bees. The expression of detoxification (GSTD1) and immune-related genes (abaecin, defensin1, and hymenopteacin) in N. perilampoides also changed over time in response to imidacloprid. Gene expression was always lower in bees after 8 days of exposure to imidacloprid (LC10 or LC20) than it was after 4 days. Our results demonstrate that N. perilampoides stingless bees are extremely sensitive to imidacloprid, even at low concentrations, and provide greater insight into how stingless bees respond to pesticide toxicity. This is the first study of its kind to look at detoxification systems and immune responses in Mexican stingless bees, an ecologically and economically important taxon.

Activities of Antioxidant and Proteolytic Systems and Biomarkers in the Fat Body and Hemolymph of Young Apis mellifera Females

Simple Summary

The proteolytic system consists of compounds that, similar to “scissors”, cut proteins found in bee cells (e.g., to activate these proteins) or released by pathogens. During these reactions, reactive oxygen species are created and then removed by antioxidants. The actions of the proteolytic and antioxidant systems are enhanced by biomarkers. These compounds are produced mainly in the fat body and then released into the hemolymph. We determined the activities of these compounds in various localizations/segments of the fat body and in the hemolymph in females with increased reproductive potential, i.e., queens and rebels, and in normal (sterile non-rebel) workers. Rebels are workers who resemble the queen in terms of anatomical, behavioural, and physiological features. It was revealed that the activities of these compounds in the rebels were between those of queens and normal workers. Normal workers had higher activities of the proteolytic and antioxidant systems in the fat body and hemolymph than the other females. These results are important for understanding the functioning of the fat body, the stress ecology, and the formation of the different castes of Apis mellifera females.

Abstract

The proteolytic and antioxidant systems are important components of humoral immunity, and these biomarkers indicate the immune status. These compounds are synthesized in the bees’ fat body and released into the hemolymph. Their functions maintain the organism’s homeostasis and protect it against adverse environmental factors (including pathogens). We determined the activities of acidic, neutral, and alkaline proteases and their inhibitors, as well as superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), and the level of total antioxidant potential (TAC). These compounds were investigated in the fat body and hemolymph in the females with increased reproductive potential, i.e., queens and rebels, and in normal (non-reproductive sterile non-rebel) workers. The phenoloxidase (PO) activities were determined in the hemolymph. The normal workers had higher activities of proteases and their inhibitors, SOD and CAT, in the fat body and hemolymph, compared to the queens and rebels. The protease inhibitors were not usually active in the queens. As we predicted, the rebels revealed values between those of the queens and normal workers. The highest activities of proteases and antioxidants were identified in the fat body from the third tergite in comparison with the sternite and the fifth tergite. These results are important for oxidative stress ecology and give a better understanding of the functioning of the fat body and the division of labor in social insects.