Varroa Destructor Research Articles

Evidence of circulating recombinants between deformed wing virus and Varroa destructor virus-1 in honey bee colonies in Türkiye.

Deformed wing virus (DWV), which is an important honey bee virus transmitted by Varroa destructor (V. destructor), causes colony losses in honey bee colonies. This study aimed to investigate the prevalence and genetic diversity of DWV in honey bees in Türkiye and to determine the role of V. destructor in the transmission of the genetic variants of DWV. Honey bee samples were collected from 62 apiaries, by simple random sampling, during March 2022 and April 2023. The presence of V. destructor in collected bee samples was examined using a stereo microscope. Real-time RT-PCR was used for the detection of DWV-A and DWV-B (Varroa destructor virus-1 (VDV-1)) viruses. Genetic characterisation of the positive samples was conducted by sequencing polyprotein genomic region. Considering the V. destructor infestation rate of 3% as relevant, out of the 62 apiaries examined, 17 (27.4%) were positive. However, DWV-A and VDV-1 specific RNA was not detected in V. destructor samples. VDV-1 specific RNA was detected in 6.5% (4/62) of the apiaries, whereas DWV-A was not detected in the sampled apiaries. Phylogenetic analysis showed that isolates detected in this study were located in a separate cluster from previously characterised DWV-A and VDV-1 isolates. According to RDP4 and GARD analyses, DWV-VDV-1 recombination breakpoints were detected in field isolates. To the best our knowledge, this is the first report of the presence of VDV-1-DWV recombinants in Türkiye. Further studies are needed to determine the impact of VDV-1-DWV recombinants and their virological and antigenic properties.

Transcriptional responses of detoxification genes to coumaphos in a nontarget species, Galleria mellonella (greater wax moth) (Lepidoptera: Pyralidae), in the beehive environment

The greater wax moth Galleria mellonella is a cosmopolitan pest of hives of the western honey bee Apis mellifera, where it remains exposed to varroicides applied by beekeepers in past decades as pest management chemicals for control of Varroa destructor, a devastating ectoparasite of bees. The prolonged presence of coumaphos residues, an organophosphate varroicide, in beeswax may be responsible for current levels of tolerance exhibited by G. mellonella, a non-target species that infests beehives. In this study, a field-collected strain of waxworms exhibited a higher LC50 value for coumaphos than that of a laboratory strain that had not been continuously exposed to coumaphos residues at field concentrations. Despite its higher tolerance for coumaphos, the field strain experienced growth inhibition at ecologically relevant concentration of coumaphos. Moreover, at low environmental concentrations that did not alter growth, detoxification gene expression levels were substantially altered. RNA-Seq analysis revealed 1181 and 658 differentially expressed genes in fat body and midgut, respectively, with 378 and 186 of those genes upregulated. This large-scale upregulation encompassed 21 genes encoding cytochrome P450 monooxygenases (CYPs), 13 encoding UDP-glycosyltransferases (UGTs), 5 encoding glutathione-S-transferases (GSTs), 2 encoding carboxylesterases (COEs), and 2 encoding ABC transporters (ABCs) in either tissue. Expression analysis of 13 selected candidate detoxification genes by RT-qPCR was consistent with their expression from RNA-Seq data. In sum, our results indicate that long-lasting pesticide residues in beeswax from past Varroa mite management may continue to act as selective agents on detoxification systems of hive residents other than the initial target species and that multiple resistance mechanisms to these chemicals may coexist within the beehive fauna.

The selection traits of mite non-reproduction (MNR) and Varroa sensitive hygiene (VSH) show high variance in subsequent generations and require intensive time investment to evaluate

The honey bee ectoparasite Varroa destructor is the main cause of honey bee colony losses worldwide. Over the last decades, several projects have focused on improving the robustness of Apis mellifera against this parasitic mite. Selection traits, such as mite non-reproduction (MNR) and Varroa sensitive hygiene (VSH), are favored selection factors in Varroa resistance projects. VSH is a trait where adult honey bees remove the Varroa-infested brood. During this process, the female mites are arrested in their reproductive cycle leading to a reduction of the Varroa population within the bee colony. From 2019 to 2022, 1402 queens were instrumentally inseminated with single or multiple drones in a breeding program. Colonies headed by these queens were established annually, and the MNR and VSH levels were analyzed. VSH was evaluated in response to cells artificially infested with Varroa, and colonies with high VSH values were used to generate our selected VSH stock. Despite crossing high VSH drones and queens, we measured a remarkable heterogeneity of MNR and VSH in the next generation(s), most likely due to the well-described, high recombination rate in the honey bee genome. When assessed multiple times in the same colony, great variance between measurements was observed. Detailed evaluations of daughter colonies are thus required if selection programs want to breed colonies with reliable VSH traits. This constant need to evaluate all offspring to ensure the desirable resistance traits are present results in high workloads and great expenses in selection programs. Furthermore, such large-scale breeding programs are inefficient due to high fluctuations between measurements and generations, indicating we need to develop new approaches and improved methods for assessing Varroa resistance.

Nested object detection using mask R-CNN: application to bee and varroa detection

In this paper, we address an essential problem related to object detection and image processing: detecting objects potentially nested in other ones. This problem exists particularly in the beekeeping sector: detecting varroa parasites on bees. Indeed, beekeepers must ensure the level of infestation of their apiaries by the varroa parasite which settles on the backs of bees. As far as we know, there is no yet a published approach to deal with nested object detection using only one neural network trained on two different datasets. We propose an approach that fills this gap. Therefore, we improve the accuracy and the efficiency of bee and varroa detection task. Our work is based on deep learning, more precisely Mask R-CNN neural network. Instead of segmenting detected objects (bees), we segment internal objects (varroas). We add a branch to Faster R-CNN to segment internal objects. We extract relevant features for internal object segmentation and suggest efficient method for training the neural network on two different datasets. Our experiments are based on a set of images of bee frames, containing annotated bees and varroa mites. Due to differences in occurrence rates, two different sets were created. After carrying out experiments, we ended up with a single neural network capable of detecting two nested objects without decreasing accuracy compared to two separate neural networks. Our approach, compared to traditional separate neural networks, improves varroa detection accuracy by 1.9%, reduces infestation level prediction error by 0.22%, and reduces execution time by 28% and model memory by 23%. In our approach, we extract Res4 (a layer of the ResNet neural network) features for varroa segmentation, which improves detection accuracy by 11% compared to standard FPN extraction. Thus, we suggest a new approach that detects nested objects more accurately than two separate network approaches.

Detection of mutations in the voltage-gated sodium channel gene of Varroa destructor (Acari: Varroidae) populations

The honeybee (Apis mellifera) ectoparasite, Varroa destructor, is one of the most important honeybee pests worldwide. Acaricides, including the pyrethroids (tau-fluvalinate, flumethrin), and organophosphate (coumaphos) have been applied to control this mite within apiaries, still the long-term, constant, and excessive use of these products has led to the development of resistance in many populations. Three different mutations (L925V, L925I, L925M) at position 925 and one mutation (M918L) at 918 position of the V. destructor voltage-gated sodium channel (VGSC) have been associated with the resistance to these compounds. In the present study, we examined the presence of resistance mutations in the VGSC gene, encoding the target of pyrethroids, in the V. destructor population collected from the Kayseri and Sivas provinces of Central Anatolia Region of Türkiye. A total of 200 V. destructor samples were collected from 20 apiaries in two provinces throughout 2023. To investigate the mutations in Varroa samples, the domain II region of the VGSC gene was amplified using PCR and sequenced. The nucleotide sequencing of the IIS4-IIS5 linker region of the VGSC gene revealed one amino acid change at position 925: a leucine to isoleucine substitution (L925I). No mutations at other positions were identified. Homozygous resistant alleles were detected in 20 (40 %) of the sequenced 50 samples in the study areas. However, we detected the homozygous sensitive allele (wild-type allele, L925) in the remaining samples (50/30, 60 %). The result shows that this status may indicate a problem for Varroa control in the future. Thus, alternative acaricide with a mode of action of different pyrethroids should be considered in the control of V. destructor populations in these provinces.

Infectious diseases of bees and their impact on the vital activity and honey productivity of honey bee colonies in Ukraine

The article presents the results of the study of the mass mortality of honey bee colonies in different apiaries from different regions of Ukraine. The epizootic status of 102 honey bee colonies was studied and 607 samples of pathological material were analyzed in 2021–2023. According to the results of the monitoring of the epizootic situation in Ukrainian beekeeping it was found that the share of parasitic diseases (54.4%, 74.0%, 69.3%) constantly prevails over infectious diseases. It was noted that the incidence of varroosis in honey bees (34.4%, 71.4%, 41.47%) remains the highest among other diseases. Against the background of severe damage to honey bee colonies by the Varroa mite, infectious diseases began to appear in an atypical form, which significantly complicates their differential diagnosis. A probable increase in the incidence of nosemosis in adult bees and the detection of Nosema cysts in the intestines of bees, both in spring and summer, and the detection of cysts in honey indicate the spread of another pathogen, Nosema cerana, which causes nosemosis in the summer season. The reason for the periodic mass death of bees in Ukraine is the combination of a high number of parasitic Varroa mites in the honey bee colony with the presence of bee infection with microsporidia Nosema spp. These pathogens negatively affect the immunity of the honey bee colony, and cause exacerbation of latent infections in bees, which leads to a decrease in the number of honey bee colonies, weakening their viability and reducing the quality of honey products

Causal network linking honey bee (Apis mellifera) winter mortality to temperature variations and Varroa mite density

Winter season is a critical time for honey bees (Apis mellifera) colonies when individual mortalities may lead to total colony losses or diminish productivity in subsequent seasons. A deeper understanding of the causes and consequences of winter mortality is required. In this study, we analyzed winter (November–March) individual bee mortality in an apiary in Central Europe from 1991 to 2023. We observed consistency in mortality times among years, but also some systematic departures from the shared trend. We distinguished four clusters of year-specific mortality trajectories. However, we found no statistically significant differences in means of spring (March–May), autumn (October), winter (November–March) temperatures, or autumn Varroa destructor density among clusters. Nevertheless, our insights into the dynamics of individual bee mortality may be important for determining critical moments during wintering when implementing additional protective measures could prove beneficial. Hypothesis-driven path analysis indicated causal links in our study system, including both direct and indirect influences. The density of V. destructor in autumn was positively related to temperature, especially in the preceding spring, but to a lesser extent also in autumn. Increased winter mortality was related to lower winter temperatures and a higher mite infestation in autumn. We found no significant effects of individual winter mortality on honey harvests in subsequent seasons. Honey harvest was determined by bee abundance in spring, and the latter, unexpectedly, was not related to winter mortality. Our study adds to accumulating evidence of the major role of weather and climatic conditions in the resilience of honey bee colonies and improves our understanding of mortality processes. We highlighted the importance of causative factors, especially seasonal temperatures and V. destructor density, and their potential as predictive indicators of individual winter mortality, bee colony fate, and honey productivity.

Population Dynamics of the Mite Varroa destructor in Honey Bee (Apis mellifera) Colonies in a Temperate Semi-Arid Climate.

This study aimed to analyze the population dynamics of the mite Varroa destructor in honey bee (Apis mellifera) colonies in a temperate semi-arid climate in Mexico. Ten colonies homogeneous in population, food stores, and levels of mite infestation were used. The mite infestation rate in brood and adult bees, total number of mites, daily mite fall, brood and adult bee population, and food stores were determined periodically for 10 months. There was a significant effect (p < 0.05) of sampling period on the population of V. destructor in adult bees, brood, total mite population, and daily fallen mites. The total mite population increased by 26% on average per colony. The increase in brood amount reduced the mite infestation rate in adult bees, and the opposite occurred when the brood decreased. Monitoring V. destructor populations by recording fallen mites is more reliable than determining mite infestation rates in bees, as mite fall has a dynamic pattern similar to that of the total mite population. The best period to apply an acaricide treatment in the region of study is between November and December because most mites were in the phoretic phase, since there was less brood in the colonies compared to other times.

Tracking Varroa Parasitism Using Handheld Infrared Cameras: Is Eusocial Fever the Key?

The Varroa destructor is the most significant bee parasite and the greatest threat to bee health all around the world. Due to its hidden lifestyle, detection within the brood cell is only possible through invasive techniques. Enhancing detection methods is essential for advancing research on population dynamics, spread, selection efforts, and control methodologies against the mite. In our study, we employed infrared imaging to measure the thermal differences in parasite and intact Apis mellifera worker broods. Experiments were conducted over two years at the MATE Kaposvár Campus in Hungary involving five beehives in 2022 and five beehives in 2023. A FLIR E5-XT WIFI handheld infrared camera was used to create a heat map of capped brood frames. Our results indicate that the resolution of these cameras is sufficient to provide detailed IR images of a bee colony, making them suitable to detect temperature differences in intact and Varroa parasitized capped brood cells. Mite parasitism causes a time-dependent and sustained temperature increase in developing bee pupae, observable regardless of mite number. Our work demonstrates two different heating patterns: hotspot heating and heating cells that are responsible for the elevated temperature of the Varroa-infested cells as a social fever response by the worker bees. Based on our results, future research combined with AI-based image evaluation software could offer beekeepers and researchers practical and valuable tools for high-throughput, non-invasive Varroa detection in the field.

Study of Eucalyptus pauciflora L. characteristics from Algeria and its impact on the mite affecting honeybees Apis mellifera

Essential oils play a crucial role in biological control against parasites threatening the beekeeping stock, both in Algeria and globally. Their appropriate use helps reduce the adverse effects of chemical products on human health and the environment. The purpose of this study is to analyze the components of Eucalyptus pauciflora essential oil grown in Algeria and to evaluate its impact on the marine shrimp Artemia salina and the mite Varroa destructor, while also comparing it to other species of Eucalyptus from the same region namely, Eucalyptus robusta, globulus, sideroxylon, and amygdalina, which have been examine in previous research. Steam distillation of fresh leaves from Eucalyptus pauciflora yielded 0.73% essential oils. This plant contains a total of thirty-nine chemical compounds, among which the most significant are 1,8-cineole (57.45%), β-cymene (5.44%), spathulenol (5.38%), trans-verbenol (4.31%), and α-pinene (3.11%). A lethality test on brine shrimp (BSL) revealed that Eucalyptus pauciflora exhibits toxicity with a median lethal concentration (LC50) of 53.51 ppm. Field trials conducted on hives infested with Varroa destructor showed that the acaricidal effect of Eucalyptus pauciflora is superior to that of amygdalina and sideroxylon species, but inferior to that of globulus and robusta species, all sourced from the same herbarium (Draa Naga) in northeastern Algeria. The results of this research highlight the benefits of Eucalyptus essential oils to be integrated into the formulation of natural acaricides that are environmentally friendly to combat Varroa destructor infestation.

Colonies under dysbiosis benefit from oxalic acid application: the role of landscape and beekeeping practices in microbiota response to treatment

AbstractThe Varroa destructor mite causes severe losses of Apis mellifera colonies, requiring recurring treatments. One such treatment is oxalic acid (OA), considered ecological. However, it is unclear whether OA affects the honey bee gut microbiota or other hive-associated microbiotas. Herein, we studied the effect of three OA treatments (trickling at 2.1% or 4.2%, and sublimation through Varrox®) upon microbial communities associated with workers’ gut, hive bee bread and pupae, sampled from conventionally or ecologically managed colonies under different anthropization levels (located in urban, rural or mountainous landscapes). We hypothesized that treatment with OA would impact the diversity and composition of bacteria and/or eukaryotic communities, and that the effect would be dose-dependent and specific to the beehive niche. Results showed that the microbiomes of apiaries under different anthropization levels and management strategies differed prior to OA application. Neither the bacterial nor the fungal communities of bee bread and pupae shifted due to OA treatment. Independent of the dosage and the application method (trickling or sublimation), OA induced slight compositional changes in the bacterial profiles of honeybee guts. Those changes were stronger the higher the anthropization (in colonies from urban areas under conventional management). OA treatment reduced the relative abundance of several pathogens, such as Nosema ceranae, and decreased the overall bacterial diversity down to values found in less anthropized colonies. Thus, our results suggest that, aside from managing Varroa infestations, OA could have beneficial effects for stressed colonies while not impairing honey bee resilience from a microbial point of view.

Effect of some natural compounds and varroacides on varooa mites (varroa destructor) in honeybee (apis mellefra) colonies during winter season in el gharbiya governorate, egypt

Effect of some natural compounds and varroacides on varooa mites (varroa destructor) in honeybee (apis mellefra) colonies during winter season in el gharbiya governorate, egypt

Determination of The Prevalence of Honey Bee Diseases and Parasites in Samples from Sivas Province

Honey bees, Apis mellifera L. (Hymenoptera: Apidae), are the most important pollinators of agricultural products and plants in the natural environment. Honeybees are an important ecosystem component due to their role in nature and agricultural production. Bacterial, fungal, viral, and parasitic factors in bee farms are among the most important causes of honey bee colony losses. Honey bee diseases (bacterial, fungal and viral) and parasites are among the most important factors limiting beekeeping development and production efficiency in Türkiye. In addition to diseases caused by bacterial and fungal agents, diseases caused by viral agents are very diverse. Viruses, especially mixed infections, cause colony losses and are the most important factors in the decline of honey bee colonies. In this study the presence and prevalence of honey bee pathogens (Varroa destructor, Nosema ceranae, Paenibacillus larvae, and nine viruses) in suspicious samples with colony losses were investigated in Sivas province. For this purpose, microscopic, microbiological, and molecular methods were investigated on larvae and adult bee. The results showed that the most common viral pathogens in samples from Sivas province were Deformed Wing Virus (70%), Apis mellifera Filamentous Virus (60%), Black Queen Cell Virus (60%), Sacbrood Virus (55%) and Varroa destructor virus-1 (40%), respectively. In some samples, it was observed that there was a double (17.5%), triple (30%), quadruple (22.5%), or even quintuple (17.5%) association of viral agents. The viral infection/varroa coexistence rate was determined to be 50%. It was determined that 22.5% of the samples examined contained Nosema spores, while 12.5% were positive for P. larvae. Revealing the distribution of bee diseases will help beekeepers in disease-fighting and taking measures. This study showed the presence of the AmFV and the Varroa destructor virüs-1 in the Sivas province of Türkiye for the first time.

Interactive effects of chlorothalonil and Varroa destructor on Apis mellifera during adult stage

The interaction between environmental factors affecting honey bees is of growing concern due to their potential synergistic effects on bee health. Our study investigated the interactive impact of Varroa destructor and chlorothalonil on workers' survival, fat body morphology, and the expression of gene associated with detoxification, immunity, and nutrition metabolism during their adult stage. We found that both chlorothalonil and V. destructor significantly decreased workers' survival rates, with a synergistic effect observed when bees were exposed to both stressors simultaneously. Morphological analysis of fat body revealed significant alterations in trophocytes, particularly a reduction in vacuoles and granules after Day 12, coinciding with the transition of the bees from nursing to other in-hive work tasks. Gene expression analysis showed significant changes in detoxification, immunity, and nutrition metabolism over time. Detoxification genes, such as CYP9Q2, CYP9Q3, and GST-D1, were downregulated in response to stressor exposure, indicating a potential impairment in detoxification processes. Immune-related genes, including defensin-1, Dorsal-1, and Kayak, exhibited an initially upregulation followed by varied expression patterns, suggesting a complex immune response to stressors. Nutrition metabolism genes, such as hex 70a, AmIlp2, VGMC, AmFABP, and AmPTL, displayed dynamic expression changes, reflecting alterations in nutrient utilization and energy metabolism in response to stressors. Overall, these findings highlight the interactive and dynamic effects of environmental stressor on honey bees, providing insights into the mechanisms underlying honey bee decline. These results emphasize the need to consider the interactions between multiple stressors in honey bee research and to develop management strategies to mitigate their adverse effects on bee populations.

Resistance of Varroa destructor against Oxalic Acid Treatment-A Systematic Review.

As Varroa destructor is one of the most important pathogens of Apis mellifera, there are numerous treatment methods, including pharmaceutical and biotechnological approaches. However, the rapid development of resistance to synthetic acaricides by Varroa destructor has become a significant concern. To date, there have been no investigations into the development of resistance to organic acids. This review examines the potential risk of oxalic acid resistance development by evaluating literature sources from the past 30 years following the PRISMA 2020 guidelines. Median annual efficacies are calculated and reviewed over time for several application methods. An efficacy higher than 70% is determined as not resistant. Independent of the method of application, no resistance development can be observed, although there are some outliers of the annual median. These outliers can be explained by brood status or study setting. However, the result is limited by the low number of efficacy values, and further standardised studies are needed.

Functional redundancy and niche specialization in honeybee and Varroa microbiomes.

The honeybee (Apis mellifera) is a key pollinator critical to global agriculture, facing threats from various stressors, including the ectoparasitic Varroa mite (Varroa destructor). Previous studies have identified shared bacteria between Varroa mites and honeybees, yet it remains unclear if these bacteria assemble similarly in both species. This study builds on existing knowledge by investigating co-occurrence patterns in the microbiomes of both Varroa mites and honeybees, shedding light on potential interactions. Leveraging 16S rRNA datasets, we conducted co-occurrence network analyses, explored Core Association Networks (CAN) and assess network robustness. Comparative network analyses revealed structural differences between honeybee and mite microbiomes, along with shared core features and microbial motifs. The mite network exhibited lower robustness, suggesting less resistance to taxa extension compared to honeybees. Furthermore, analyses of predicted functional profiling and taxa contribution revealed that common central pathways in the metabolic networks have different taxa contributing to Varroa mites and honeybee microbiomes. The results show that while both microbial systems exhibit functional redundancy, in which different taxa contribute to the functional stability and resilience of the ecosystem, there is evidence for niche specialization resulting in unique contributions to specific pathways in each part of this host-parasite system. The specificity of taxa contribution to key pathways offers targeted approaches to Varroa microbiome management and preserving honeybee microbiome. Our findings provide valuable insights into microbial interactions, aiding farmers and beekeepers in maintaining healthy and resilient bee colonies amid increasing Varroa mite infestations.

Organic farming and annual flower strips reduce parasite prevalence in honeybees and boost colony growth in agricultural landscapes

Abstract Despite the major role that insect pollinators play in crop production, agricultural intensification drives them into decline. Various conservation measures have been developed to mitigate the negative effects of agriculture on insect pollinators. In a novel comparison of the efficacy of three conservation measures on honeybee colony growth, we monitored experimental honeybee colonies in 16 landscapes that comprised orthogonal gradients of organic agriculture, annual flower strips and perennial semi‐natural habitats. Using structural equation modelling, we assessed the effects of conservation measures on the prevalence of 11 parasites, Varroa destructor loads and their collective impact on colony growth. Increasing area coverage of perennial semi‐natural habitat related to higher V. destructor load and indirectly to lower colony growth. Increasing area of annual flower strips was associated with lower V. destructor load and indirectly with higher colony growth. Increasing area of organic farming related to lower parasite richness and also directly to improved colony growth. Synthesis and applications: Landscape features can affect pollinators directly through the provision of food resources and indirectly through modulation of parasite prevalence. To promote honeybee colony health in agro‐ecosystems, our results suggest that organic agriculture and annual flower strips should be prioritized conservation measures. Landscape management should consider the merits and demerits of different measures to sustain healthy populations of pollinators in agro‐ecosystems.

Acaricidal properties of Corsican Humulus lupulus L. (Cannabaceae) essential oils against Varroa destructor: a honeybee health perspective

ABSTRACT Six Corsican essential oils (EOs) from Humulus lupulus were studied for their activity against Varroa destructor adults and Apis mellifera pupae. The GC/MS analysis of EOs showed that the major compounds of all accessions were α-Humulene, Myrcene, α-Selinene, β-Selinene, (E)-β-Farnesene, and (E)-β-Caryophyllene. Bioassays showed that EOs from each accession acted as toxins and repellents against V. destructor adults, with lower toxicity towards A. mellifera pupae. In terms of efficacy against V. destructor adults, Smaragd 2020 oil displayed the highest performance, with LC50 and LC90 values of 2.33 and 7.83 µL/L air, respectively. Meanwhile, Smaragd 2019 and Tettnanger EOs showed moderate toxicity, with LC50 values of 3.101 and 3.66 µL/L air, along with LC90 values of 11.67 and 19.89µL/L air, respectively. The oils from Biguglia and Ajaccio were strongly repellent to Varroa adults. At the lowest concentration (2 µL/mL), these EOs exhibited percentage of repellence greater than 70% after 2h exposure, with RC50 values of 1.66 and 1.26 µL/L air, respectively. Concerning their insecticidal effects, EOs demonstrate reduced toxicity towards bee pupae when compared to Varroa mites. Notably, Ajaccio stands out for inducing lower mortality among bee pupae, with a selectivity ratio below 2 and LC50 of 11.25 µL/L air.

Sensorizing a Beehive: A Study on Potential Embedded Solutions for Internal Contactless Monitoring of Bees Activity.

Winter is the season of main concern for beekeepers since the temperature, humidity, and potential infection from mites and other diseases may lead the colony to death. As a consequence, beekeepers perform invasive checks on the colonies, exposing them to further harm. This paper proposes a novel design of an instrumented beehive involving color cameras placed inside the beehive and at the bottom of it, paving the way for new frontiers in beehive monitoring. The overall acquisition system is described focusing on design choices towards an effective solution for internal, contactless, and stress-free beehive monitoring. To validate our approach, we conducted an experimental campaign in 2023 and analyzed the collected images with YOLOv8 to understand if the proposed solution can be useful for beekeepers and what kind of information can be derived from this kind of monitoring, including the presence of Varroa destructor mites inside the beehive. We experimentally found that the observation point inside the beehive is the most challenging due to the frequent movements of the bees and the difficulties related to obtaining in-focus images. However, from these images, it is possible to find Varroa destructor mites. On the other hand, the observation point at the bottom of the beehive showed great potential for understanding the overall activity of the colony.

MSPB: a longitudinal multi-sensor dataset with phenotypic trait measurements from honey bees

We present a one-year-long multi-sensor dataset collected from honey bee colonies (Apis mellifera) with rich phenotypic measurements. Data were collected non-stop from April 2020 to April 2021 from 53 hives located at two apiaries in Québec, Canada. The sensor data included audio features, temperature, and relative humidity. The phenotypic measurements contained beehive population, number of brood cells (eggs, larva and pupa), Varroa destructor infestation levels, defensive and hygienic behaviors, honey yield, and winter mortality. Our study is amongst the first to combine a wide variety of phenotypic trait measurements annotated by apicultural science experts with multi-sensor data, which facilitate a broader scope of analysis. We first summarize the data collection procedure, sensor data pre-processing steps, and data composition. We then provide an overview of the phenotypic data distribution as well as a visualization of the sensor data patterns. Lastly, we showcase several hive monitoring applications based on sensor data analysis and machine learning, such as winter mortality prediction, hive population estimation, and the presence of an active and laying queen.