Search Results (267)

The process of aging in organisms is associated with progressive metabolic changes that affect energy production. In our study, we compared the activities/concentrations of components related to the Krebs cycle and the respiratory chain (such as acetyl-CoA, IDH, AKG, succinate, fumarate, NADH₂, UQCR, COX and ATP) in the hemolymph and fat body segments (tergites 3 and 5, sternite) in naturally and prematurely (affected by V. destructor) aging workers. Tergite 3 showed the highest metabolic activity, indicating its key role in energy storage and production. In naturally aging workers, the concentrations/activities of the tested components were higher in all the segments of the fat body and all the age groups when compared to the prematurely aging workers. The concentrations/activities of these components increased with age, usually reaching the maximum at 28 days of age in the fat body segments of naturally aging workers, and then decreasing in the oldest ones (at 35 days of age). An analysis of changes in the metabolic processes can provide a lot of important information on the mechanisms of aging. In the future, such studies can contribute to the development of effective strategies to delay the aging processes and improve the overall condition of bee colonies. Full article

Royal jelly (RJ), a secretion from nurse bees, is a key factor in honeybee caste differentiation and a high-value product in apitherapy. Despite its economic and biological importance, factors affecting its yield and composition remain insufficient. This study investigated the impact of grafted larval age and sex and the collection day of RJ on its yield and physicochemical characteristics. Three independent experiments were conducted using strong Apis mellifera L. colonies. Larvae of different ages (first, second, and third) were grafted, and RJ was harvested 24, 48, and 72 h post grafting. Additionally, worker and drone larvae were used to assess the effect of larval sex. RJ was analyzed for moisture, protein, sugar, and 10-hydroxy-2-decenoic acid (10-had) content. Results showed that RJ yield significantly increased with collection day, with the third day being optimal. Protein content declined over time, while moisture content rose, although sugar levels and 10-HDA remained stable. Second-day larvae yielded the highest RJ volume without affecting composition. Larval sex did not significantly influence either RJ yield or composition. The results of this study may provide valuable insights into the quality determinants of royal jelly, enabling beekeepers to optimize production for both enhanced royal jelly yield and the rearing of higher-quality queen bees. Full article

Effective control of the parasitic mite Varroa destructor in honey bee (Apis mellifera) colonies relies on integrated pest management (IPM) strategies to prevent mite populations from reaching economic injury levels. Formulations of oxalic acid combined with glycerin may provide a viable summer treatment option in continental Northern climates. This study evaluated the efficacy of oxalic acid and glycerin strips compared to oxalic acid dribble and 65% formic acid when applied in mid-August. Mite levels and colony health parameters were assessed, and honey samples from oxalic acid-treated colonies were analyzed for residue levels. Results showed that the oxalic acid and glycerin strips had a moderate acaricidal efficacy (55.8 ± 3.2%), which was significantly higher than those of 65% formic acid (42.6 ± 3.2%) and oxalic acid dribble (39.5 ± 4.3%), which did not differ between them, suggesting potential for summer mite control. No significant adverse effects on cluster size, worker mortality, queen status, or colony survival were observed. Oxalic acid and glycerin increased the proportion of spotty brood patterns at early timepoints after treatment, but recovery was noted after 45 days of starting the treatment. Similar effects on brood were observed with 65% formic acid 14 days after starting the treatment, with recovery by 28 and 45 days after starting the treatment. No significant differences in oxalic acid residues in honey from the control and treatment colonies were found. Oxalic acid and glycerin strips might help control varroa mite populations, delaying their exponential growth and helping reduce economic losses for beekeepers, but this treatment should be considered as part of an IPM strategy and not a stand-alone method for V. destructor control. Full article

The search for substances that increase the immunity of bees is becoming a necessity in the era of various environmental threats and the declining immunocompetence of these insects. Therefore, we tested the biological and physicochemical properties of 7-diethylamino-4-hydroxycoumarin (7DOC). In a cage test, two groups of bees were created: a control group fed with sugar syrup and an experimental group fed with sugar syrup with the addition of 7DOC. In each group, the longevity of the bees was determined and the protein concentrations and antioxidant activities in the bees’ hemolymph were determined. The bees fed with 7DOC lived 2.7 times longer than those in the control group. The protein concentrations and activities of SOD, CAT, GPx and GST, as well as the TAC levels, were significantly higher in the hemolymph of the supplemented workers. To confirm these potent biological properties of 7DOC, the UV-Vis spectra, emission and excitation of fluorescence, synchronous spectra and finally the fluorescence lifetimes of this compound were measured using the time-correlated single photon counting method, in various environments differing in polarity and in the environment applied in bee research. This compound was shown to be sensitive to changes in solvent polarity. The spectroscopic assays were complemented with crystallographic tests of the obtained monocrystals of the aforementioned compounds, which attested to the aggregation effects observed in the spectra measurements for the selected coumarin. The research results confirm that this compound has the potential to be implemented in apiary management, which will be our application goal, but further research into apiary conditions is required. Full article

Schefflera oleifera honey (SH) is produced from the nectar of S. Oleifera by worker bees. Due to its unique properties and potential biological activities, this winter honey has attracted much attention. In this study, the physicochemical characteristics, antioxidant and antibacterial activities, antitumor effect against HepG2 cells, and its potential mechanisms of SH were systematically evaluated. The results showed that different SH samples differed significantly in their physicochemical characteristics. The 910 chemical components, including 52 kinds of phenols, phenolic acids, and flavonoids, were detected in the methanol extract of SH using UHPLC-MS/MS by non-targeted metabolomics. Based on our limited knowledge, solanine and soyasaponin I are the first determined components in honey, and they may be used as characteristic substances of SH for identification and adulteration. SH had a weaker inhibitory effect against Salmonella typhimurium and Staphylococcus aureus than MH (UMF 10+), analyzed by MBC and MIC assays. Network pharmacology analysis showed that 95 overlapping targets were found between the active ingredients of SH and liver cancer cells (HepG2), which were enriched in KEGG of the PI3K-Akt pathway, Lipid and atherosclerosis, Proteoglycans in cancer, etc. The IC₅₀ of SH against HepG2 cells was 5.07% (dw/v), which is lower than the glucose, fructose, and sucrose contents in SH on HepG2 cells, of 16.24%, 9.60% dw/v, and 9.94% dw/v, respectively. SH significantly down-regulated the expression of EGFR, AKT1, and SRC in HepG2 cells (p < 0.05), determined by an enzyme-linked immunosorbent assay kit, and induced cell cycle arrest and apoptosis by multiple pathways. These results provide a theoretical basis for its potential application in developing functional foods and additives. Full article

Background/Objectives: The objectives of this study were to identify the genetic effects involved in the expression of individual honeybee grooming behavior in response to Varroa destructor and to determine if there is an association between the expression of this behavior and the infestation levels of Varroa in the honeybee colonies. Methods: The study was conducted in a population of 112 colonies composed of six segregating genetic groups that were derived from two honeybee lines that were selected for high and low individual honeybee grooming behavior. The individual honeybee grooming behavior of 3974 workers from the 112 colonies was measured by the time it takes a bee to respond in performing grooming behavior after a mite was placed on her body. The population growth of Varroa in the colonies was measured over a period of six months. Results: Differences between the genetic groups were found in the expression of individual honeybee grooming behavior (p < 0.01). The distribution of means of the genetic groups fits a genetic additive and dominance effects model for the expression of individual honeybee grooming behavior (r² = 0.95; p < 0.01). Differences between the genetic groups were found in the colony population growth of Varroa over a period of six months (p < 0.01). A positive correlation was found between the mean individual honeybee grooming behavior of the colonies and the Varroa level of infestation in the colonies (r = 0.57; p < 0.01). Conclusions: The results indicate that additive and dominance genetic effects are associated with honeybee individual grooming behavior and that this trait has an effect on the levels of Varroa infestation in the colonies. Full article

Abiotic stressors threaten honeybee health, jeopardizing pollination services critical to agriculture and biodiversity. Here, we identified the AmVgR gene, which encodes a member of the low-density lipoprotein receptor family, and examined its function in the response of Apis mellifera to adverse abiotic stress. AmVgR exhibited peak expression in adult workers and was significantly upregulated under heat, cold, heavy metal, and pesticide exposure. RNAi-mediated knockdown of AmVgR suppressed antioxidant enzyme activities, elevated the levels of oxidative damage markers, and downregulated antioxidant gene expression. Crucially, AmVgR silencing reduced survival under H₂O₂-induced oxidative stress, indicating its essential role in stress resilience. Our findings highlight AmVgR as a key regulator of antioxidant defense during development and environmental adaptation in Apis mellifera. This study provides mechanistic insights into bee stress physiology and proposes AmVgR as a novel target for enhancing pollinator protection strategies. Further research should elucidate its molecular pathways and translational applications in mitigating abiotic stress impacts. Full article

The development of wireless technology and the desire to improve communication electromagnetic fields (EMFs) of various frequencies have become common across the honey bee’s foraging landscape. There has been discussion for many years about the possible impact of electromagnetic fields on living organisms. Artificial radio fields emit frequencies ranging from 100 kHz to 300 GHz. The presented research aimed to demonstrate the influence of the radiofrequency electromagnetic field (RF-EMF) with a frequency of 900 MHz on the behavior of honey bees in laboratory conditions. For this experiment, we used wooden cages to house honey bee workers immediately after they emerged. Bee workers were divided into control and experimental groups. Bees in the control group were not exposed to RF fields, while the experimental groups were exposed to 900 MHz electromagnetic fields of different intensities and durations of exposure. Bees’ behavior was analyzed with an appropriate computer program. Behavioral analysis of bees was performed immediately after exposure and seven days after exposure. Our research has shown that the radio field (900 MHz) affects the behavior of bees compared to the control group, although not all results are statistically significant. Significant effects were observed seven days after exposure in walking, flight, and individual contact. However, it is worth extending the study to include the impact of an RF-EMF on the expression of genes responsible for bee behavior. Full article

A honeybee (Apis mellifera) colony is a superorganism of complex social dynamics. Within the colony, communication between individuals and castes is crucial for maintaining homeostasis. Such complex interactions are possible thanks to semiochemicals called pheromones. The spectrum of pheromonal communication in bee colonies is wide and differs between castes, especially the queen and the workers. Gland morphology and compounds of secretions result in alterations in both physiological and behavioral responses to certain pheromones in castes. The queen’s glands produce pheromones that maintain her reign and induce division of labor among workers. Workers’ pheromones are adapted to multiple tasks performed by this caste within the colony. This review outlines a neurophysiological pathway in the perception pheromone molecule, with a specific description of the individual anatomical structures essential for the path, such as the morphology of antennae, sensilla, antennal lobes and mushroom bodies. Later on, the study provides insight into specific aspects of the differences between the two castes (queen and workers) in terms of complex pheromonal communication in the hive, by describing the pheromones present in it (QMP, tergal gland pheromone, Dufour gland pheromone, Nasonov pheromone, sting alarm pheromone and tarsal gland pheromone). Full article

10-Hydroxy-2-decenoic acid (10-HDA), a major fatty acid (FA) component of royal jelly, is synthesized in the mandibular glands (MGs) of worker honeybees. Despite its well-documented nutritional and therapeutic significance, the biosynthetic pathway and regulatory mechanisms of 10-HDA production remain largely unresolved. In this study, the molecular basis of 10-HDA biosynthesis and regulation in the MGs of newly emerged bees (NEBs), nurse bees (NBs), and forager bees (FBs) were investigated using RNA sequencing and weighted gene co-expression network analysis (WGCNA). A five-step biosynthetic pathway for 10-HDA was proposed, and cross-species analysis of Apis mellifera and A. cerana revealed the conserved expression patterns of 15 key enzymes involved. Functional validation via RNA interference (RNAi) demonstrated that knockdown of acyl-CoA Delta(11) desaturase (d11ds, LOC551527), a key enzyme in FA desaturation, led to a 50% reduction in 10-HDA levels. Protein–protein interaction (PPI) network analysis further identified transcriptional regulators Kay and Drep-2 as potential modulators of 10-HDA metabolism. This study provides the first comprehensive mechanistic model of 10-HDA biosynthesis in honeybee MGs and highlights the labor-specific regulation of FA metabolism. These findings offer promising genetic targets for improving the royal jelly quality through genetic technology. Full article

High temperature is normally harmful to an organism. However, honey bees evolve, maintaining a relatively higher colony temperature of 34.5 °C in the long reproduction period. To determine the effect of such a higher colony temperature on adult bees and its biological significance, newly emerged bees were reared in cages at 34.5 °C and room temperature of 25.0 °C, respectively. Their survival rate, head weight, royal jelly-secreting gene expression, and morphology of the hypopharyngeal gland were investigated. Moreover, 40-day-old bees with significant differences in survival rate between the two temperature groups were subject to transcriptome and lipidome analysis. The result showed that the higher colony temperature was overall negative for the bees’ longevity. Transcriptome analysis showed that fatty acid metabolism-related items were enriched and the involved genes were upregulated in honey bees reared at 34.5 °C compared with the honey bees reared at 25.0 °C. Lipidomic analysis further validated that fatty acid metabolism, especially sphingolipid metabolism, was significantly altered. Such upregulation of fatty acid metabolism-related genes was also detected in young adult bees of 5 days old reared at 34.5 °C. These bees had heavier head weights, higher expression of royal jelly-secreting-related genes, and more developed hypopharyngeal glands. Such results showed that the colony temperature of 34.5 °C could accelerate the development process of newly emerged bees to be nurse bees, significantly increasing the colony nurturing capability, which in turn increased the development speed, size, and survivability of the colony. Thereby, the colony temperature of 34.5 °C shortened the lifespan of individual bees, but obtained huge returns at the colony level, with remarkable biological significance. Full article

This study specifically examines the post-reproductive lifespan and ovarian activation in honeybee workers (Apis mellifera) with differing life expectancies. Drawing on the “grandmother hypothesis”, which postulates that older females enhance the survival and reproductive success of their descendants, we aimed to determine if similar patterns exist in eusocial insects. We conducted an experiment with newly emerged honeybee workers, dividing them into two groups: an untreated control group and an injured group with shortened lifespans due to thorax puncturing. The workers were monitored in an experimental apiary, and observations regarding ovarian development and hypopharyngeal gland size were recorded at various age intervals. Our results demonstrated a significant difference in lifespan between the control and injured bees, with injured individuals living notably shorter lives. The size of the hypopharyngeal gland, crucial for brood food production, varied significantly with respect to age and treatment, suggesting that physical injuries adversely affected physiological development. More intriguingly, our findings indicated that older honeybee workers displayed reduced ovarian activation, implying a potential reproductive cessation. This phenomenon can be interpreted as a form of menopause, which represents a strategic shift in energy investment from personal reproduction toward contributing to the colony as older individuals age. Full article

Monitoring insect activity at hive entrances is essential for advancing precision beekeeping practices by enabling non-invasive, real-time assessment of the colony’s health and early detection of potential threats. This study evaluates deep learning models for detecting worker bees, pollen-bearing bees, drones, and wasps, comparing different YOLO-based architectures optimized for real-time inference on an RTX 4080 Super and Jetson AGX Orin. A new publicly available dataset with diverse environmental conditions was used for training and validation. Performance comparisons showed that modified YOLOv8 models achieved a better precision–speed trade-off relative to other YOLO-based architectures, enabling efficient deployment on embedded platforms. Results indicate that model modifications enhance detection accuracy while reducing inference time, particularly for small object classes such as pollen. The study explores the impact of different annotation strategies on classification performance and tracking consistency. The findings demonstrate the feasibility of deploying AI-powered hive monitoring systems on embedded platforms, with potential applications in precision beekeeping and pollination surveillance. Full article

Melanin is an important component of the body color of honeybees, and its formation changes with the age of a capped brood of bees. However, up to now, the regulatory mechanism of melanin formation in honeybees remains unclear. To analyze the differential expression profile of microRNAs (miRNAs) in worker bees of Apis mellifera and to reveal the regulatory roles of differentially expressed miRNAs (DEmiRNAs) and mRNAs in the formation process of melanin during the capped brood stage, we used sRNA-seq technology and related software to analyze samples from four key developmental stages during the capped brood stage, when body color develops in Apis mellifera, namely, mature larvae (L0), pre-pupae (PP3), early pupae (P6) and mid-pupae (P9). A total of 1291 miRNAs were identified by bioinformatics. Three comparison groups were analyzed: L0 vs. PP3, PP3 vs. P6, and P6 vs. P9. A total of 171, 94, and 19 DEmiRNAs were identified in these groups, respectively, which regulate 1481, 690, and 182 differentially expressed target mRNAs (target DEmRNAs). The functional analysis of target DEmRNAs indicated that DEmiRNAs might regulate the formation of capped brood melanin in honeybees by activating expression changes in key genes in signaling pathways, such as the Wnt signaling pathway, melanogenesis, and the Toll and Imd signaling pathway, through activating miR-315-x, miR-8, ple, yellow family genes, wnt1, etc. Our research provides a theoretical basis for future analysis of the regulatory role of miRNAs in the formation of melanin in honeybees. Full article

Honey bees are crucial to both the ecosystem and the economy. However, they are subject to different influences that can lead to a loss of genetic diversity. In this study, we used mitochondrial DNA information and nuclear microsatellite markers to compare worker individuals that strictly meet the morphological breed standard of the Pannonian bee in Hungary to those with morphological disorders (yellow color of the abdomen). Additionally, this study involves Carniolan colonies from two European countries and other bee subspecies as a reference group that might have crossed into the Pannonian bee. As for the mitochondrial DNA, the combined assessment of COI and 16S genes identified six haplotypes. Based on the tRNAleu-cox2 intergenic region (E2/H2), our samples belonged to the C evolutionary lineage. According to the microsatellite data, the level of inbreeding was low in all groups investigated, and only the genotypes of the Pannonian bee showed significant deviation from the Hardy–Weinberg equilibrium state. Cluster analysis and the Discriminant Analysis of Principal Components showed that bees that failed the morphological breed identification had started to diverge genetically from those meeting the breed standards, becoming more similar to the Carniolan bee. Our findings suggest that the genetic status of the Pannonian bees investigated in this study is satisfactory. However, in order to maintain an adequate level of diversity, periodic genetic monitoring of the colonies is necessary. Full article