Search Results (202)

This study aimed to evaluate the efficacy of various control alternatives against Varroa destructor in Apis mellifera colonies in a semi-arid region of Mexico. One hundred and ten homogeneous colonies, with a uniform population and infestation level of V. destructor, were randomly distributed into the following 11 experimental groups (10 colonies/group): amitraz, oxalic acid in glycerin (OA-G), oxalic acid in sugar syrup (OA-SS), ethanolic extracts of Bursera penicillata, Larrea tridentata, and Lippia graveolens, powdered sugar dusting, three vehicle controls (vegetable oil, ethanol, glycerin), and one untreated control. Efficacy was determined by recording mite fall during the treatment period relative to a subsequent reference treatment. Significant differences were observed among treatments (p < 0.0001). Amitraz was the most effective (94.4%), followed by OA-G (85.1%). The OA-SS and plant extracts showed intermediate efficacy (62.1% to 73.7%), while sugar dusting showed lower values (55.8%) but still higher than the control (31.2%). These findings support the restricting of amitraz use to minimize resistance risk and suggest implementing OA-G as a high-efficacy alternative. Furthermore, ethanolic plant extracts and powdered sugar dusting combined with sticky bottom boards may serve as accessible, complementary tools within integrated pest management programs to reduce reliance on synthetic acaricides and mitigate the development of resistance. Full article

Recent high annual losses of honey bee (Apis mellifera) colonies, averaging 40% in the United States from 2008 to 2025, are concerning for beekeepers, growers, policy makers, and scientists. Viruses, the most abundant group of honey bee pathogens, impact honey bee fitness and contribute to colony losses. Several studies have utilized next-generation sequencing (NGS) technologies to discover new honey beeinfecting viruses and expand our understanding of the honey bee virome. Herein, we examined the viromes of honey bees obtained from longitudinally monitored, commercially managed colonies that experienced population decline (average ~44%) during the 2022–2023 beekeeping season. We hypothesized new viruses or virus genome variants may be associated with these declines. To test this hypothesis, we sequenced RNA obtained from virus-augmented honey bee samples from representative colonies managed by four beekeeping operations in California. We discovered three undescribed partitivirus-like sequences that were prevalent and abundant in all beekeeping operations, a new Lake Sinai virus, and a sequence variant of acute bee paralysis virus. In addition, we re-sequenced the genomes of 16 previously characterized bee and/or Varroa destructor mite infecting viruses and two previously described, but not well-characterized, partitivirus-like sequences (i.e., Apis mellifera associated partiti-like virus 1 and Hubeipartiti-like virus 34). Virus abundance was greater in libraries representing colonies that died during the monitoring period. Full article

Climate change exerts an increasing impact on the health and resilience of honey bees through a combination of rising temperatures, altered precipitation patterns, and intensified parasitic and infectious pressure. The present study aims to analyze climatic conditions in Bulgaria for the period 2021–2024 and to evaluate the results of a national survey conducted among beekeepers, focusing on winter colony losses during the 2023/2024 season and the feeding strategies applied. The survey was carried out in 2024 among 70 beekeepers from 20 administrative regions of the country, managing a total of 8935 bee colonies. The data were analyzed using descriptive statistics and stratified by region. The reported average winter mortality was 2.22% (198 colonies), with pronounced territorial variability. The most frequently indicated self-reported probable cause of losses was bee diseases, with varroosis identified as the dominant factor. Analysis of management practices revealed widespread application of combined feeding schemes based on plant-derived supplementary feeds, primarily administered in spring (March–April) and late summer (August–September). The obtained results differ from published national data for 2024, according to which total colony losses reached 16.3%, while losses associated with mortality or severe demographic collapse accounted for 11.6%. Despite the limitations inherent to the survey-based approach and self-reported data, the results suggest that integrated management combining parasite control with targeted nutritional support through the use of Bulgarian herbal supplementary feeds may coincide with the winter survival patterns reported within the surveyed sample. Full article

This study provides an updated overview of Anthophila (wild bees and honey bees) diversity and conservation status in Algeria, explicitly distinguishing between the managed honey bee (Apis mellifera) and native wild Anthophila species. Using a systematic PRISMA-based literature analysis, more than 179 bee species have been documented across Mediterranean and semi-arid ecosystems, confirming their irreplaceable contribution to ecosystem resilience and crop pollination and beekeeping systems. The majority of Algeria’s Anthophila diversity is represented by endemic and native wild bees that sustain natural ecosystems. However, they are under growing human-caused (anthropogenic) pressures in the Anthropocene, including pressure from habitat loss and fragmentation, agricultural intensification, widespread pesticide use, and climate change. In addition, pathogenic threats such as Varroa destructor, Nosema, and associated viruses are well documented in honey bees, while evidence for their presence and impact in wild bees in Algeria remains very limited. These stressors not only weaken specialist species but also accelerate biotic homogenization dominated by A. mellifera. Recent genomic research on native honey bee populations has revealed adaptive signatures linked to immunity and social behavior, offering new opportunities for innovative conservation strategies based on molecular and genetic tools. Such insights highlight the value of preserving local strains, which may hold key traits for resilience under changing environmental conditions. To safeguard Anthophila biodiversity, this study underscores the urgent need for Algeria to implement proven conservation strategies, including habitat restoration initiatives and Anthophila-friendly farming approaches, which are common internationally but remain largely unaddressed at the national scale. By integrating cutting-edge genetic research, ecological restoration, and sustainable innovation, Algeria, with its diverse habitats and largely unexplored Anthophila fauna, holds considerable potential for advancing biodiversity conservation strategies that also support food security. However, this potential can only be realized through further in-depth research and comprehensive species inventories. Full article

Cuba is in a unique situation in which it has a large (220,000 managed colonies) and isolated honey bee population due to a 60+ year ban on the importation of bees. Despite this, the ectoparasitic mite Varroa destructor arrived in 1996, and with it came deformed wing virus (DWV). In 2018, an island-wide survey detected varroa and DWV in 91% of colonies. In this study, we conducted a full-virome analysis on some of these samples, along with additional samples collected in 2021. For the first time, we detected two variants of Lake Sinai Virus and confirmed the absence of the normally widespread black queen cell virus in Cuba. We also detected both DWV-A and DWV-B master variants, with DWV-B being the dominant variant. Interestingly, the DWV-B/A recombinant was also detected, indicating that despite Cuba’s isolated nature, the pattern of DWV evolution mirrors that found in the USA and Europe. However, this pattern is not found in neighboring Latin America, China, or Japan, where the DWV-A master variant continues to be dominant. How and why two distinct evolutionary DWV pathways have arisen remain a mystery. Full article

The species Inula helenium belongs to the genus Inula (Asteraceae) and exhibits antibacterial and anti-inflammatory properties. It is used in respiratory and skin diseases. Its bioactivity is attributed to its eudesmanolide components, mainly to alantolactone and isoalantolactone. These components were isolated in high purity from the plant’s dried roots, either via multiple column chromatography separations or via repeated recrystallization. Two more eudesmanolides structurally similar to their parent compounds were isolated, namely 11,13-dihydro-alantolactone and 11,13-dihydro-isoalantolactone. The secondary metabolites and their derivatives were characterized in detail, for the first time, via NMR spectroscopy, GC-MS, and HRMS. Synthetic modification of the natural component structure was considered necessary for structure–activity relationship studies and biological tests. Thus, each compound was converted to its nitrile and then to the corresponding acid, or to its azide derivative and then corresponding amine. Antioxidant studies were conducted on the parent compounds, their derivatives, and the methanolic and hexane plant extracts using the DPPH radical method. The study revealed a strong antioxidant capacity of the methanolic extract. Acaricidal studies of both natural products and synthetic analogs against Varroa destructor and the comparison of their activity with the parent natural product costic acid, as well as one of its synthetic congeners, indicated that the “from nature to synthesis and vice versa” approach led to active compounds as well as to meaningful conclusions regarding the “pharmacophore” groups in the structural framework of the acaricides. Full article

Background: Varroa destructor is the major threat to honey bee health, and selective breeding for resistance traits such as Varroa-sensitive hygiene represents a promising long-term strategy for controlling mite populations. However, breeding programs that rely on highly controlled mating schemes, including single-drone instrumental insemination, may reduce allelic diversity at the complementary sex determiner (csd) locus, potentially increasing the production of non-viable diploid males and compromising colony fitness. Methods: To evaluate whether csd diversity can be maintained under these conditions, we characterized the hypervariable region of csd in a selectively bred Apis mellifera population subjected to four years of selection. Using a validated de novo assembly pipeline, we reconstructed 43 amino-acid sequences from 33 diploid worker pupae sampled across 13 colonies. Results: Seven distinct alleles were identified, five of which were shared among multiple colonies and corresponded to variants already described in the literature, while two were private to individual colonies and novel in the literature. Colony-level frequency data revealed a moderate diversity: the most common allele was detected in nine colonies, with an allelic frequency of 31%. Moreover, the expected heterozygosity of the population was estimated at 0.79. Conclusions: Overall, these findings show that csd diversity can be partially maintained even under strong selective pressure when multiple maternal lines are retained, and they underscore the importance of incorporating genetic information into breeding decisions to support the long-term sustainability of selective breeding programs. Full article

Pests contribute significantly to the loss of Apis mellifera colonies in a multifactorial context that includes viruses, pesticides, nutritional deficiencies, and climate change. This review critically summarises diagnostic techniques (morphological, molecular, automated) and epidemiological methods for the main parasites (Varroa destructor, Vairimorpha spp., Acarapis woodi, Tropilaelaps spp., Aethina tumida, Lotmaria passim, Crithidia mellificae), evaluating trade-offs between sensitivity, specificity, cost, and practicality. There is no universal gold standard; the methodological choice must be contextualised. A decision-making framework structured on four pillars (Primary objective, Resource constraints, Epidemiological context, Ethics/Regulatory) is proposed to guide optimal selections, with application examples and testable hypotheses for future validation. Limitations of emerging technologies (reduced accuracy in the field for AI and LAMP), gaps in multi-pathogen synergies (including viruses and bacteria), interactions with pesticides, and climate impacts with explicit uncertainties are discussed. A global perspective and a One Health approach are adopted, identifying research priorities for integrated diagnostic tools, validated predictive models, and sustainable strategies. Full article

This study investigates the synthesis and potential applications of the coordination compound cobalt(III) complex tris[N-(prop-2-en-1-yl)hydrazinecarbothioamide]-cobalt(III) chloride ([Co(Tsc)₃]Cl₃). The complex has been synthesized via the reaction of cobalt(II) chloride hexahydrate with N-(prop-2-en-1-yl)hydrazinecarbothioamide in ethanol. Its antioxidant activity has been evaluated using 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assay, demonstrating a significant effect with an IC₅₀ of 7.3 µmol/L. Toxicity evaluations using Daphnia magna showed a low half maximal inhibitory concentration (LC₅₀) of 56.3 µmol/L. Experimental results have showed that [Co(Tsc)₃]Cl₃ significantly elevated the total antioxidant status (TAS) of the hemolymph of honeybees and larvae, increasing it by 5 and 8 times, respectively. The IC₅₀ values for antioxidant activity were 2.5 mg/mL in bee hemolymph and 1.3 mg/mL in larval hemolymph, notably lower than control values of 13.6 mg/mL and 10.0 mg/mL. The stimulatory effect of the coordination compound [Co(Tsc)₃]Cl₃ on TAS was five times higher than that of vitamin C. Additionally, [Co(Tsc)₃]Cl₃ exhibited acaricidal properties, effectively inhibiting Varroa destructor with an lethal concentration (LC₅₀) of 0.2 µmol/L. These findings indicate that this cobalt complex could serve both a natural antioxidant and an effective acaricide, offering a promising approach to improv bee health and sustainability in apiculture. Full article

Varroa destructor remains a major threat to honey bee (Apis mellifera) health, requiring effective and sustainable control strategies. In this study, a formic acid-based product (Formic Pro™) was tested for its varroacidal efficacy and effects on hygienic behavior of honey bee colonies. Sixty hives were assigned to three groups: Formic Pro group (n = 30), Positive control treated with amitraz (n = 15), and untreated Negative control (n = 15). Efficacy was assessed by daily mite drop counts, while hygienic behavior was evaluated before and after treatment using the “pin-killed” brood method. The Formic Pro group achieved a mite mortality rate of 88.37% ± 0.23, while amitraz as a control exerted 94.30% ± 0.95 efficacy. The treatment was well tolerated, with no queen losses, minimal and transient brood effects, followed by brief bearding on the first day of trial. Hygienic behavior significantly increased in the Formic Pro group (PCC from 96.69% to 99.01%, p < 0.001), while it declined in the Negative control and remained unchanged in the Positive control group. These results demonstrate that the tested formic acid-based product provides high acaricidal efficacy which is tolerated well in colonies and that it stimulates a key behavioral defense mechanism through hygienic behavior, providing benefits both for Varroa control and colony resilience. Full article

Varroa destructor is a major health problem for honey bees (Apis mellifera). Selective breeding of Varroa-resistant bees is a suitable long-term solution to Varroa parasitism. After three generations of selecting honey bees for lower (resistant) and higher (susceptible) V. destructor population growth (LVG and HVG, respectively), LVG bees showed increased behavioral, cellular, and humoral immunity against Varroa. To further analyze resistance, the transcriptomes of both bee genotypes were examined, revealing that parasitized LVG bees had fewer differentially expressed genes (DEGs) than parasitized HVG bees, indicating a reduced impact by Varroa with greater resistance. Annotations of the altered DEGs showed that both genotypes were affected with an increased demand for energy, protein, and repair during parasitism. However, there were also DEGs in LVG bees, possibly related to resistance, such as up-regulation of odorant binding protein genes and down-regulation of the corazonin receptor gene, whereas DEGs in the HVG bees may be more related to stress, such as up-regulation of ATP synthase and down-regulation of the transcription factor dorsal. Overall, this work shows that selection for LVG and HVG bees resulted in genotypes with widespread differences in gene expression during Varroa parasitism, which may be related to resistance and susceptibility. Full article

Infestation by Varroa destructor represents one of the major challenges for beekeeping, as it compromises both colony health and honey productivity. The objective of this study was to evaluate the efficacy of different organic treatments for the control of V. destructor and their effect on honey production in Apis mellifera colonies located on the central region of Tamaulipas, Mexico. A total of 150 colonies were assigned to five treatments: T1, oxalic acid with glycerin; T2, sublimated oxalic acid; T3, Thymol, T4; HappyVarr; and T5, an untreated control. Mite infestation (initial and final) and honey production were analyzed using a non-parametric approach and were evaluated with the Kruskal–Wallis test, and when significant differences were detected, Steel–Dwass multiple comparisons were performed. To examine the relationship between infestation reduction and honey yield, Spearman’s rank correlation was applied. No significant differences were observed in the initial infestation levels. However, final infestation levels showed highly significant differences among treatments (p < 0.0001), with T1, T2, T3, and sublimated oxalic acid (T4) significantly reducing mite infestation compared with the control. Sublimated oxalic acid represents the most effective and productive control method under the tested conditions. Honey production also differed significantly among treatments (p < 0.0001), with the highest yields recorded in T3 and T4. A strong negative correlation was detected between final infestation and honey production (p < 0.0001). In conclusion, treatments based on oxalic acid (particularly sublimated) and HappyVarr proved effective in reducing V. destructor infestation and improving honey production, highlighting their relevance as viable alternatives for sanitary management in beekeeping. Full article

Honey bee health and productivity are strongly linked to management practices and biosecurity measures. We collected and analyzed 744 practice records from 191 peer-reviewed field studies published since 1995, each documenting the impact of a specific hive intervention on colony health or productivity parameters. Practices were categorized into good beekeeping practices (n = 128, 17.2%) and biosecurity measures (n = 616, 82.8%) and grouped by management or pathogen theme, geographic region, and season. Most research originated from Europe (34.6%) and North America (33.4%), with nearly all focused on Apis mellifera (99.9%). Varroa control dominated (57.0%), followed by general apiary management (17.2%) and american foulbrood (9.7%). For varroosis, “soft” acaricides such as oxalic and formic acid accounted for 58.5% of records, while “hard” synthetic products represented 21.0%. Within general apiary management, colony management was most frequent (46.9%). For american foulbrood, antibiotics (41.7%) and biotechnical methods (22.2%) were prominent. Tropilaelaps app. treatments relied mainly on “soft” acaricides (81.5%), while small hive beetle control focused on in-hive traps (55.9%). Seasonally, most interventions occurred from August to October, with AFB measures peaking in spring and early summer. The dataset highlights regional research gaps and offers a structured, expandable framework to guide future research and support evidence-based decision-making in beekeeping and advisory services. Full article

The proteolytic system plays a crucial role in maintaining the homeostasis and defence against pathogens. Its proper functioning depends on the balance between the activities of proteases and their inhibitors. The disturbing of this balance, caused, for example, by Varroa destructor, brings about physiological/metabolic changes leading to premature aging. Therefore, our study aimed to investigate the effect of V. destructor on the activities of acidic, neutral, and alkaline proteases and their inhibitors in bee hemolymph and fat body segments (from tergite 3, tergite 5 and sternite). The parasite caused a decrease in the protease and protease inhibitor activities, accelerating the aging process. In healthy worker bees, proteolytic activity in the fat body segments increased with age, peaking at 21–28 days, and subsequently declined in 35-day-old workers. Additionally, it was observed that tergite 5 was the segment characterized by the highest activity of the proteolytic system, which indicates that it can be used as a biomarker of aging and immunity. Studying the proteolytic system is important because it allows for a more detailed understanding of immunity mechanisms, aging processes, and responses to infection, which may contribute to the development of preparations promoting apian health. Full article

In the current study, the impact of different acaricide treatments against Varroa (such as amitraz strips, oxalic and formic acid strips impregnated with glycerin, or the sublimation or instillation of oxalic acid) on glycerol residue levels of propolis was investigated. Propolis samples were collected from five beehives located in Chalkidiki (northern Greece), where all mentioned treatments were used and chemically analyzed and compared to control ones. Propolis samples were collected on days 7, 21, and 65 after the application of Varroa treatments, extracted with ethanol/water (70:30), silylated, and then analyzed using GC-MS, showing the predominance of diterpenes. The sublimation of oxalic acid and the amitraz treatment yielded a low glycerol residue (5.12% and 5.09% from 9.98% and 9.19%, respectively) in propolis specimens, while glycerin-impregnated oxalic acid strips led to elevated glycerol percentages (24.30% from 20.51%), unlike the reduced glycerol residues for all other treatments (instillation: 12.60% from 14.48% and glycerin-impregnated formic acid strips: 8.91% from 9.25%) and controls (3.27% from 6.30%). Furthermore, Principal Component Analysis (PCA) and the corresponding biplot illustrated how the sample composition varied across treatments and sampling days, highlighting the chemical constituent categories that most strongly contributed to these distinctions. These findings suggest that the use of glycerol-impregnated strips should be avoided in future beekeeping treatments against varroosis, as they could have a negative impact on the quality of propolis either for nutritional or medicinal applications. Full article