Search Results (238)

Apis mellifera L. is an important pollinator of both wild and domesticated crop plants, thus greatly contributing to plant biodiversity and commercial agriculture. However, in field conditions, honey bees remain exposed to different pesticides which ultimately affect colony health parameters and their associated ecological services. In the current study, the individual toxicities of sub-lethal doses of two distinct insecticides (bifenthrin and acetamiprid) belonging to different groups (pyrethroid and neonicotinoid) were assessed against the foraging activity, social interactions, and longevity of A. mellifera. The bees were exposed to individual doses of both insecticides via the dietary trophic route through contaminated pollen and nectar under natural field conditions. Sunflower crop (Hysun-33) was sown at nine different sites with an isolation distance of 3 km, and was treated with different doses (1/2, 1/4, 1/10, and 1/20 of the recommended field doses) of both insecticides. However, the untreated control crop plots were not subjected to any chemical treatments (bee colonies received no insecticide, and served as the baseline for making comparison). Twenty-seven bee colonies were introduced in these sites after seven days of treatment applications. Significant differences were observed in the foraging activity of A. mellifera (including bees going out from the hive, returning foragers, and those carrying pollens). The fecundity, adult longevity, and social behaviors like trophallaxis and antennation were significantly lower in bees exposed to higher individual insecticidal concentrations. However, the hatching duration, larval duration, and pupal duration were not affected by the tested insecticidal treatments. Overall, these findings demonstrate that the dietary trophic exposure of sub-lethal doses of insecticides compromised colony activities, which is indeed a matter of concern regarding the existing pesticide application methods in different agro-ecosystems. Such impacts may ultimately impair the survival of colonies, particularly when bees remain exposed to these chemicals over an extended period of time. Therefore, future studies must consider the pesticide application techniques and their application timing to mitigate the direct and indirect negative impacts of pesticides on pollinators. Full article

Propolis, a sticky bee hive product collected from resinous plant sources by Apis mellifera bees, exhibits a wide range of biological and pharmacological properties, primarily attributed to its rich composition of bioactive constituents, including phenolic acids, esters, and flavonoids. In this study, the antioxidant properties of 76 liquid propolis solutions from 18 different countries were investigated based on their dry matter, total phenolic and total flavonoid contents, antioxidant capacities, and phenolic profiles. The antioxidant activities of propolis from various geographic regions, including Latvia, Croatia, New Zealand, San Marino, Russia, France, Romania, Italy, Estonia, Brazil, Belgium, Germany, Slovenia, Japan, the United States of America (USA), the United Arab Emirates (UAE), Spain, and Korea, were compared. Total phenolic and flavonoid contents, as well as total antioxidant capacity (Cupric Reducing Antioxidant Capacity—CUPRAC method), were analyzed by spectrophotometry, and the major constituents were investigated by liquid chromatography–mass spectrometry (LC-MS/MS). Antioxidant test results indicated that 29 products scored below 10 mg Trolox equivalent (TE)/mL, and only 14 were scored above 100 mg TE/mL. The results showed that the total phenolic content of the samples ranged from 0.1 to 107.5 mg Gallic acid equivalent (GAE)/mL, while total flavonoid content varied between 0.1 and 174.5 mg Catechin equivalent (CE)/mL. Based on the CUPRAC assay, total antioxidant capacity values ranged from 0.1 to 492.3 mg TE/mL. Among the 76 analyzed samples, nine products exhibited antioxidant capacity values exceeding 150 mg TE/mL. In all of these samples, phenolic profiling confirmed the presence of propolis, and the analytical results were consistent with the information declared on the product labels. Hence, this study provides a comprehensive, real-market evaluation of commercial propolis products by integrating spectrophotometric assays with LC-MS-based targeted metabolomics profiling, highlighting formulation- and product type-driven differences in phenolic composition and antioxidant capacity beyond geographical origin. Full article

The supplementary feeding of bee colonies under conditions of limited natural food sources is essential for maintaining their health and productivity. Pollen is a major source of protein for bees, collected during plant flowering. Its absence negatively affects the secretory activity of the hypopharyngeal glands (HPGs) in young nurse bees. This study aimed to assess the effect of different protein sources provided during the spring period on the development of HPGs in worker bees. An experiment was conducted with 28 bee colonies divided into seven groups of four colonies each—one control and six experimental. The colonies were fed soy isolate (Glycine max), brewer’s yeast (Saccharomyces cerevisiae), spirulina (Arthrospira platensis), pea protein (Pisum sativum), and bee pollen (a mixture of pollens from various plant species). The results confirmed the critical role of pollen, as 40% of bees in the pollen-fed group exhibited HPGs at grade 4. The group supplemented with spirulina showed similar results (35.8%), indicating its potential as an alternative protein source. These findings highlight the importance of proper protein supplementation and suggest that spirulina could serve as a promising substitute for pollen in early spring feeding to support colony development. Full article

Honey bees (Apis mellifera) are the main pollinators of many plant species, particularly agricultural crops. The concern over Colony Collapse Disorder of bee colonies in recent years necessitates the use of new approaches for their conservation in in situ and ex situ conditions. Modern techniques for cryopreservation of drone spermatozoa allow for the preservation of their genetic diversity. Some of the challenges in the field of cryopreservation are the alterations induced by the low temperatures, including morphological disruptions, plasma membrane integrity, formation of reactive oxygen species, DNA fragmentation, loss of motility, mitochondrial activity and viability, early hyperactivation, depletion of proteins from the acrosome region, premature capacitation, reduced sperm–oocyte fusion, and the occurrence of other cellular cryoinjuries. The objective of the current study is to contribute to the ongoing efforts in identifying substances added to semen extenders aimed at inhibiting cryogenic-induced changes. Our study investigates the impact of antioxidant supplements, scilicet vitamins C, vitamin E, and L-carnitine, on attenuating the adverse effects of cryogenic storage on drone spermatozoa. Using a Computer-Assisted Sperm Analysis, we evaluated the effectiveness of various antioxidants added to the extender in maintaining sperm motility parameters following liquid nitrogen storage. The data indicated significant differences in sperm traits among treatments with supplements after post-thawing. These findings emphasize the advantageous contribution of these added antioxidants within semen extenders for drone spermatozoa in preserving sperm quality parameters. The establishment of novel protocols for cryogenic storage of honey bee drone spermatozoa, incorporating low-cytotoxicity additives, is of utmost importance for the conservation of this endangered species. Full article

In honeybees (Apis mellifera L.), the queen ensures the reproduction of the colony. Environmental contamination that could alter this function could compromise the survival of the colony. Ionizing radiation could be such a factor, but its effects have never been studied in queens. The effects of gamma irradiation on queen bees were evaluated under laboratory conditions. The queens were irradiated for 14 days at dose rates of 0.1, 13, and 3500 µGy/h, and mortality, reproductive potential, and several physiological biomarkers were investigated. Irradiation did not affect the survival of the queens or the number of sperm stored in the spermatheca. However, sperm viability and reproductive potential decreased significantly at 13 and 3500 µGy/h. Among the biomarkers analyzed (antioxidant defenses, detoxification, metabolism, immunity, neural activity), no significant differences were observed between the modalities, with the exception of an increase in thoracic LDH activity at 13 µGy/h, confirmed by multivariate analyses indicating metabolic changes. These results show that ionizing radiation does not induce lethality at the tested dose rates, but significantly impaired fertility and metabolism of queen bees, with potential consequences for colony stability, whose ecological significance remains to be confirmed under field conditions. Full article

Characterizing the botanical composition of pollen is essential to understanding the floral resources used by bees. While microscopy is the traditional method, it is time-consuming and limited in taxonomic resolution. Molecular tools such as DNA barcoding offer a more precise and cost-effective alternative for identifying plant taxa in mixed pollen samples. This study implemented a preliminary and cost-effective molecular approach to identify the botanical origin of pollen stored in bee bread from Apis mellifera hives in a tropical dry forest fragment in La Paz, Cesar, using rbcL and matK genes as markers. The chloroplast markers rbcL and matK were amplified and Sanger-sequenced from three independent bee hives, each processed in duplicate as technical replicates. The BLAST+ 2.17.0 results from Sanger sequences showed a sequence identity ranging from 89%–99%, with rbcL showing higher and more consistent matches than matK, suggesting stronger discriminatory power, while the lower identity in one hive indicated a more complex pollen mixture. However, matK detected a greater number of taxa overall (i.e., 70% of the total, 64 genera) compared with rbcL (i.e., 50%, 46 genera). Both markers overlapped in approximately 20% of the taxa, most of which (i.e., 94%) belonged to the family Cactaceae. This indicated that, although rbcL provided more reliable matches, matK contributed to broader taxonomic coverage, highlighting the complementarity of both markers for mixed pollen analyses. This approach highlights its value as an exploratory tool prior to applying high-throughput sequencing strategies. Furthermore, such studies may support the development of local honey brands by validating that their products originate mainly from the biodiversity of tropical dry forests, an ecosystem currently at risk, thereby conferring both ecological and market value. Full article

The honey bee (Apis mellifera L.) is a eusocial insect widely known for its role in pollination and plant biodiversity. Diverse microorganisms, including both beneficial and pathogenic, colonize bees and play important roles in the overall hive health. Microorganisms with biocontrol properties are natural modulators of honey bee microflora. Since most studies have focused on the characterization of worker bee-associated microbes, there is a lack of information about the drones’ microbial environment. In this study, we identified cultivable yeasts from different stages of honey bee drones collected in Lithuania. Sealed larvae hosted the widest variety of yeasts. Metschnikowia species were detected across all developmental stages of drones. The assessment of functionality revealed that M. pulcherrima and M. fructicola exhibited the most pronounced biocontrol properties, accompanied by high levels of autoaggregation and hydrophobicity. Starmerella apis and M. reukaufii were distinguished by the highest autoaggregation capacity, exceeding 60%, and strong adherence to hydrocarbons. Starmerella genus yeasts demonstrated strong biofilm-forming ability. The novel information on the functionality of honey bee drone-inhabiting yeasts suggests their importance in maintaining the healthy microbiological environment of the hive. The isolated yeasts with beneficial traits may serve as candidates for future studies aimed at supporting honey bee health. Full article

This study investigates the phenomenon of ethanol hormesis in honeybees (Apis mellifera) infected with Vairimorpha (Nosema) spp., a widespread parasite that significantly impacts bee health and colony survival. Hormesis refers to a biphasic response where low doses of potentially harmful substances may elicit beneficial effects, contrasting with the detrimental impacts observed at higher concentrations. We hypothesized that low ethanol concentrations could reduce Vairimorpha spp. infection severity and improve bee lifespan. In a controlled experiment, foraging bees were divided into groups of infected and uninfected individuals, and each group (N = 50) was exposed to varying ethanol concentrations (0%, 0.0313%, 0.625%, 1.25%, 2.5%, 5%, and 10%). The results indicated that infected bees exposed to 0.625% and 1.25% ethanol exhibited the longest lifespans and the lowest Vairimorpha (Nosema) spp. spore counts, supporting the hormetic model. In contrast, higher ethanol concentrations (2.5% and above) significantly increased mortality and spore load, reaffirming the toxic effects associated with excessive ethanol intake. This study highlights the complex interactions between ethanol exposure and parasitic infection in honeybees, suggesting that ethanol at 0.625% and 1.25% may mitigate some of the harmful effects of Vairimorpha (Nosema) spp. infections. The findings have implications for understanding how ethanol, present in floral nectar, impacts honeybee health and could inform management strategies for controlling Vairimorpha (Nosema) spp. infections in bee populations. Full article

Stable pollination by honeybees (Apis mellifera L.) is essential for the reliable production of strawberries cultivated in winter greenhouses in Korea. Few studies focused on the management of pollination hives within greenhouses during flowering. Thus, this study aimed to investigate the effects of nutritional feed management by supplementing pollen patties and sugar solution on the pollination efficiency and colony longevity of honeybees under greenhouse conditions. In March, the number of foraging bees in the treatment group was 1.94 times higher than that in the control group. The number of bees inside the hive was approximately 2000 greater in February and approximately 2925 greater in March in the treatment group than in the control group. The pollen patties supplemented one time were completely consumed after 53 days, whereas 50% of the patties remained even after 70 days when supplemented three times. The commercial fruit set rate was 5.9% higher, and the fruit weight was significantly heavier, by 1.7 g, in the treatment group than in the control group, although other quality parameters showed no significant differences. Additionally, bee activity was approximately 2.2 times higher in the treatment group with sugar syrup supplementation than in the control group, but the fruit set rate or quality did not significantly differ between the two groups. These findings indicate that the feed management of honeybees during winter greenhouse strawberry cultivation is essential for stable pollination. Proper nutritional supplementation not only enhances bee activity and colony longevity but also improves strawberry productivity, leading to an estimated additional profit of approximately KRW 2.29 million (≈USD 1700) per 0.1 ha. This demonstrates that nutritional management of pollination hives provides both biological and economic benefits for greenhouse strawberry growers. Full article

Triatoma infestans is one of the primary vectors of Chagas disease. This vector has developed increasing resistance to pyrethroids, the main insecticides used for its control. Recent studies have highlighted the repellent and lethal effects of Cannabis sativa on insects, suggesting its potential use in pest management. Based on this, we hypothesize that C. sativa could be a viable bioactive for controlling T. infestans. To test this hypothesis, acetone and ethanol extracts were obtained from the inflorescences of C. sativa L. (Deep Mandarine variety) using sonication. These extracts were analyzed through gas chromatography and high-performance liquid chromatography. The repellent and lethal effects of the extracts were evaluated on fifth-instar nymphs of T. infestans from a laboratory colony, as well as on the beneficial non-target species, Apis mellifera. The most abundant terpenes identified were β-caryophyllene and β-pinene, with concentrations exceeding 100 ppm in both extracts. Cannabidiol and Δ⁹-tetrahydrocannabinol were the predominant cannabinoids. Both extracts exhibited maximum lethal activity 48 h after insect contact, with the acetone extract demonstrating a potency five times greater than the ethanolic extract. Binary combinations of C. sativa extracts with major terpenes showed dose-dependent interactions against T. infestans, ranging from strong synergy (e.g., AE + β-caryophyllene, CI = 0.06–0.17) to marked antagonism (e.g., AE + E-ocimene, CI = 1.60–4.80). Furthermore, the acetone extract showed a more effective repellent action compared to the ethanol extract, even outperforming N,N-Diethyl-meta-toluamide (DEET, positive control). At a concentration of 25 µg/cm² for 60 min, the acetone extract achieved a 100% repellent effect, whereas DEET required a concentration of 50 µg/cm² to achieve the same effect. Unlike imidacloprid (positive control), neither extract showed toxicity to adult A. mellifera at the evaluated doses. Full article

Oral diseases such as dental caries, stomatitis, and periodontitis are closely associated with biofilms that are resistant to conventional therapeutic approaches. Streptococcus sanguinis and Streptococcus mutans play a key role as primary and secondary colonizers of oral surfaces, respectively, and interact synergistically with other species, including Candida albicans, to promote the establishment and progression of infection. Objective: To evaluate the antimicrobial activity of ethanolic extracts of propolis from Tame (Arauca) on biofilms formed in co-cultures from reference strains and co-cultures with clinical isolates of oral pathogens. Methodology: Propolis was collected from Apis mellifera hives placed in rural Tame (Arauca), located in the foothills of the Eastern Andes (Colombia). Ethanolic extracts of propolis (EEP) were prepared in a 0.07 g/mL concentration and biological characterization was performed on single and complex co-cultures of S. mutans (serotype c), S. sanguinis, and C. albicans using disc diffusion test, determination of MIC and BMC, growth curves and biofilm formation. The cell viability and metabolic activity of primary cell cultures derived from a dental pulp explant were evaluated using the MTT assay. Results: EEP exhibited higher inhibition zones than chlorhexidine against S. mutans and C. albicans and lower efficacy against S. sanguinis. Among the microorganisms evaluated, S. mutans showed the lowest MIC and BCM values, followed by C. albicans and S. sanguinis. Growth curves and biofilm formation assays revealed higher inhibition in co-cultures of reference strains (S. mutans + C. albicans), while multi-species cultures (S. mutans + S. sanguinis + C. albicans), or clinical strains (S. mutans clinical isolated + S. sanguinis + C. albicans), showed higher resistance. Cell viability assays revealed low cytotoxicity (<30%) in primary cell cultures. Conclusions: EEPs exhibited antimicrobial activity against relevant oral pathogens, especially in simple co-cultures, supporting their potential as natural therapeutic alternatives. However, their efficacy decreases in the presence of clinical strains and complex co-cultures, highlighting the importance of considering these variables in the development of oral treatments. Full article

Nosemosis, caused by microsporidians of the genus Vairimorpha, is one of the most significant diseases affecting the honey bee Apis mellifera L. (Apidae: Hymenoptera), with negative impacts on its health and productivity. This study aimed to assess the presence of Vairimorpha ceranae in apiaries from the state of Campeche, Mexico. Honey bee samples were collected from 79 colonies across 29 apiaries, and DNA was extracted for analysis. Detection of the microsporidian parasite was achieved through amplification of the 16S small subunit ribosomal RNA gene by PCR and PAGE, revealing a high prevalence of Vairimorpha ceranae. The results represent the first confirmed record of Vairimorpha ceranae in this region, with widespread infection detected among sampled colonies. This finding is crucial for identifying the frequency and geographic distribution of this parasite in Mexico and will support the development of targeted management and control strategies adapted to local conditions, ultimately contributing to the conservation and health of honey bee populations in Campeche. Full article

There is a growing interest in protecting pollinators in cities as part of efforts to promote biodiversity and sustainable development. However, many initiatives setting up urban apiaries or CSR campaigns remain superficial and do not take into account the real needs of wild pollinators. The article examines whether various interventions like promoting the protection of bees (and other pollinators), rain gardens, and green roofs align (or do not align) with the biodiversity conservation objectives. A review of practices was conducted, identifying cases of beewashing and comparing the ecological effects of establishing apiaries with activities that promote wild pollinators. Particular attention was paid to the analysis of the bee density index, which was used to assess the relationship between the number of bee colonies and the availability of food resources and highlight the risk of overpopulation and its potential consequences. The results indicate the occurrence of overgrazing, which refers to an excessively high density of breeding bee apiaries in each studied NUTS 1 region, and their number has been steadily increasing over the analyzed period. An analysis of available strategic and planning documents of selected cities (particularly provincial capitals and Poland’s largest urban centers) reveals limited commitment to pollinator protection. Although the analysis was conducted for macroregions in Poland, this work also indicates how to properly design and communicate pollinator-friendly urban activities to truly support ecological resilience and sustainable urban development, not only in the case of Poland but also more broadly. Full article

Honey robbing, as an extreme adaptive response of honey bee colonies to resource scarcity, poses devastating threats to apiaries, yet the underlying molecular mechanisms remain poorly understood. We compared morphological traits and survival rates between robber bees and normal foragers and conducted proteomic sequencing of bee head samples. The results demonstrated that robber bees exhibited darker tergite coloration and significantly shortened lifespan. Proteomic analysis revealed that the darker coloration was primarily attributed to enhanced cuticular melanin deposition mediated by upregulated laccase-5, while the shortened lifespan mainly resulted from oxidative stress and immune suppression: the downregulation of heat shock protein 75 kDa and glutathione transferase weakened antioxidant capacity, and despite compensatory upregulation of the cytochrome P450 enzyme system, flavin-containing monooxygenases and other enzymes, oxidative damage continued to accumulate. Concurrently, downregulation of Defense protein 3 and C-type lectin 5 caused immune deficiency in robber bees. The results also showed metabolic and protein synthesis reprogramming in robber bees, specifically manifested by upregulated key enzymes in nicotinate and nicotinamide metabolism, the pentose phosphate pathway, and nucleotide metabolism, along with activation of protein synthesis-transport-export systems. We found that robber bees employ a “metabolic-synthetic co-enhancement” physiological strategy to boost short-term foraging efficiency, but this strategy simultaneously induces oxidative damage and immune suppression, ultimately shortening their lifespan. This study provides the first proteomic evidence revealing the physiological trade-offs underlying this behavior at the molecular level, offering novel insights into the physiological costs of behavioral adaptation in animals. Full article

Dearth periods associated with less floral resources negatively impact Apis mellifera colony performance. Artificial diets offer nutritional supplements to sustain bee colonies under stressful conditions. An eight-week feeding trial was conducted using various artificial diets (eight diets, including a control diet), formulated with varying quantities of pulses, yeast, fenugreek powder, vegetable oil, dry apricot powder, and powdered sugar. Colony performance of bees subjected to different artificial diets was evaluated based on diet consumption, brood area, adult bee population, worker bee longevity, honey production, and enzymatic activity. Diet-7, which uniquely combined lupin, mung bean, and chickpea flours, proved the most efficacious and was the most consumed diet (84.29 ± 1.61 g), while diet-1 showed the lowest consumption (35.30 ± 1.08 g). Maximum brood area was recorded in colonies which were offered diet-7 (1385.95 ± 14.91 cm²), followed by diet-6, whereas the lowest was observed in the control (831.03 ± 18.95 cm²). The adult bee population was highest in diet-7 (21,594.50 ± 94.55 bees/hive), while lowest in the control (diet-0) (12,625.43 ± 385.06 bees/hive). Worker bee longevity was greatest in diet-7 (49.40 ± 0.41 days) and lowest in the control group (37.01 ± 0.39 days). Honey production was also highest in diet-7 (8.86 ± 0.21 kg), while lowest in the control (2.79 ± 0.35 kg). The results further showed that the enzymatic activities of bees were significantly improved due to diet-7, with the highest values for amylase (48.62 ± 0.23 U/mg), lipase (16.85 ± 0.20 U/mg), proteinase (25.21 ± 0.18 U/mg), and α-glucosidase (39.21 ± 0.21 U/mg). In conclusion, statistical analyses confirmed that diet-7 emerged as the most effective artificial diet, enhancing colony performance across all evaluated parameters. Future research should aim to optimize diet formulations and evaluate their effectiveness on colony health, including gut microbiome and immune function, across different seasons and ecological regions. Full article