Varroa Destructor Infestation Research Articles

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.

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.

Oxalic Acid Treatment: Short-Term Effects on Enzyme Activities, Vitellogenin Content, and Residual Oxalic Acid Content in House Bees, Apis mellifera L.

Honeybees (Apis mellifera L.) have to face many challenges, including Varroa destructor infestation, associated with viral transmission. Oxalic acid is one of the most common treatments against Varroa. Little is known about the physiological effects of oxalic acid, especially those on honeybees' immune systems. In this study, the short-term effects (0-96 h) of oxalic acid treatment on the immune system components (i.e., glucose oxidase, phenoloxidase, glutathione S-transferase, catalase activities, and vitellogenin contents) of house bees were preliminarily investigated. Oxalic acid contents of bee bodies and haemolymphs were also measured. The results confirm that oxalic acid is constitutively present in bee haemolymphs and its concentration is not affected by treatment. At 6 h after the treatment, a maximum peak of oxalic acid content was detected on bees' bodies, which gradually decreased after that until physiological levels were reached at 48 h. In the immune system, the oxalic acid treatment determined a peak in glucose oxidase activity at 48 h, indicating a potential defence response and an increase in vitellogenin content at 24 h. No significant changes were recorded in phenoloxidase, glutathione S-transferase, and catalase activities. These results suggest a time-dependent response to oxalic acid, with potential immune system activation in treated bees.

Parasite and virus dynamics in the honeybee Apis mellifera unicolor on a tropical island recently invaded by Varroa destructor

In La Réunion, the established honeybee subspecies Apis mellifera unicolor, an endemic subspecies of African lineage, is facing considerable challenges. Since the introduction of the Varroa destructor mite in 2017 high colony losses have been recorded. We investigated the dynamics of V. destructor and two viruses, the Deformed Wing Virus (DWV), known to be transmitted by the mite, and the Chronic Bee Paralysis Virus (CBPV), in A. m. unicolor. Colonies from two apiaries located at 300 and 900 m a.s.l were monitored twice for one year without any acaricide treatment. The brood area, V. destructor infestation rates, DWV and CBPV prevalence and load were recorded monthly. A. m. unicolor maintained brood rearing throughout the year. Varroa destructor infestation resulted in high colony mortality (up to 85 %) and high phoretic mite rates (up to 52 mites per hundred bees). The establishment of DWV in colonies occurred after that of V. destructor and the mite infestation rate had a significant effect on the virus prevalence and load. CBPV appeared only transiently throughout the surveys. The data showed that, in tropical colonies with permanent brood rearing, V. destructor and DWV can reach high levels, but are still subject to seasonal variations that appear to be influenced by environmental conditions. This suggests that beekeeping practices could be adapted by favouring sites and periods for transhumance or acaricide treatment.

Relative impacts of Varroadestructor (Mesostigmata:Varroidae)infestation and pesticide exposure on honey bee colony health and survival in a high-intensity corn and soybean producing region in northern Iowa.

The negative effects of Varroa and pesticides on colony health and survival are among the most important concerns to beekeepers. To compare the relative contribution of Varroa, pesticides, and interactions between them on honey bee colony performance and survival, a 2-year longitudinal study was performed in corn and soybean growing areas of Iowa. Varroa infestation and pesticide content in stored pollen were measured from 3 apiaries across a gradient of corn and soybean production areas and compared to measurements of colony health and survival. Colonies were not treated for Varroa the first year, but were treated the second year, leading to reduced Varroa infestation that was associated with larger honey bee populations, increased honey production, and higher colony survival. Pesticide detections were highest in areas with high-intensity corn and soybean production treated with conventional methods. Pesticide detections were positively associated with honey bee population size in May 2015 in the intermediate conventional (IC) and intermediate organic (IO)apiaries. Varroa populations across all apiaries in October 2015 were negatively correlated with miticide and chlorpyrifos detections. Miticide detections across all apiaries and neonicotinoid detections in the IC apiary in May 2015 were higher in colonies that survived. In July 2015, colony survival was positively associated with total pesticide detections in all apiaries and chlorpyrifos exposure in the IC and high conventional (HC) apiaries. This research suggests that Varroa are a major cause of reduced colony performance and increased colony losses, and honey bees are resilient upon low to moderate pesticide detections.

The Impact of Cannabis sativa and Helianthus annuus Plants on Honey bee Colonies (Apis mellifera L.): Varroa destructor Infestation and Performances

The performance and Varroa destructor infestation percentage of the honey bee colonies placed in areas with Cannabis sativa and Helianthus annuus plants were investigated. The study was conducted in the Havza district of Samsun and Samsun Ondokuz Mayıs University campus. A total of 15 bee colonies, with five in three different areas, were used. No chemical treatment against Varroa was administered in the colonies. In various areas, significant differences were observed in the worker bee population, the brood production, and the Varroa destructor infestation on adult bees and pupal cells. It is determined that the amount of Varroa on adult bees of the colonies in the sunflower and campus areas three and two times higher when compared to the colonies in cannabis area. Sunflower plants had a significantly positive impact on colony development. Cannabis has significantly increased brood production at the end of summer and autumn, which is a very critical period for honey bees. The campus area had significant disadvantages due to a summer drought and lack of flora at the beginning of autumn. It has been concluded that cannabis and sunflower plants play an important role in supporting bees before winter. It is essential to examine the efficacy of pure extracts derived from cannabis in combating Varroa through clinical research.

Detection of Varroa destructor Infestation of Honeybees Based on Segmentation and Object Detection Convolutional Neural Networks

Varroa destructor infestation is a major factor leading to the global decline of honeybee populations. Monitoring the level of Varroa mite infestation in order to take timely control measures is crucial for the protection of bee colonies. Machine vision systems can achieve non-invasive Varroa mite detection on bee colonies, but it is challenged by two factors: the complex dynamic scenes of honeybees and small-scale and limited data on Varroa destructor. We design a convolutional neural network integrated with machine vision to solve these problems. To address the first challenge, we separate the image of the honeybee from its surroundings using a segmentation network, and the object-detection network YOLOX detects Varroa mites within the segmented regions. This collaboration between segmentation and object detection allows for more precise detection and reduces false positives. To handle the second challenge, we add a Coordinate Attention (CA) mechanism in YOLOX to extract a more discriminative representation of Varroa destructor and improve the confidence loss function to alleviate the problem of class imbalance. The experimental results in the bee farm showed that the evaluation metrics of our model are better than other models. Our network’s detection value for the percentage of honeybees infested with Varroa mites is 1.13%, which is the closest to the true value of 1.19% among all the detection values.

Honey vs. Mite-A Trade-Off Strategy by Applying Summer Brood Interruption for Varroa destructor Control in the Mediterranean Region.

In this study, we investigated the effect of queen caging on honey bee colonies' post-treatment development and the optimal timing of method application on honey production during the main summer nectar flow. We conducted the study in nine apiaries (N = 9) across six Mediterranean countries, with a total of 178 colonies. The colonies were divided into three test groups: QC1, QC2, and C. The QC1 group involved queens caged for a total of 28 days before the expected harvesting day. In the QC2 group, queens were caged for 28 days, but only 14 days before the expected harvesting day. The C group consisted of queens that were not caged, and the colonies received common local treatments. In both the QC1 and QC2 groups, the colonies were treated with a 4.2% oxalic acid (OA) solution by trickling after the queen release. Our findings revealed no significant adverse effects (p > 0.05) on colony strength at the end of the study resulting from queen caging. However, significantly lower amounts of honey were extracted from the QC1 group compared to both the QC2 group (p = 0.001) and the C group (p = 0.009). Although there were no initial differences in Varroa destructor infestation between the groups, ten weeks later, a significantly higher infestation was detected in the C group compared to both the QC1 group (p < 0.01) and the QC2 group (p = 0.003). Overall, our study demonstrates that queen caging, in combination with the use of OA, is an effective treatment for controlling V. destructor. However, the timing of caging plays a crucial role in honey production outcomes.

Epidemiology, factors influencing prevalence and level of varroosis infestation (Varroa destructor) in honeybee (Apis mellifera) colonies in different agroecologies of Southwest Ethiopia

Little information is available on the epidemiology of varroosis caused by Varroa mite, Varroa destructor infestation in Ethiopia, although it is a devastating honeybee disease that results in significant economic losses in beekeeping. Therefore, between October 2021 and October 2022, a cross-sectional study was carried out in different agroecology zones in Southwest Ethiopia to determine the prevalence and associated risk factors for varroosis, as well as the effects of this disease on honeybee colonies and honey production. A multivariate logistic regression analysis was performed to identify possible risk factors for the prevalence of V. destructor. A total of 384 adult honeybee and worker or drone brood samples were collected from honeybee colonies and examined using standard diagnostic techniques in the laboratory. The result shows that the prevalence of V. destructor was found to be 39.3% (95% CI 34.44–44.21) and 43.2% (38.27–48.18) in adult honeybees and brood, respectively. The major risk factors for the prevalence of V. destructor in the study areas included agroecology (OR = 5.2, 95% CI 1.75–14.85), type of hive (OR = 2.9, 95% CI 1.17–17.03), management system (OR = 4.3, 95% CI 1.23–14.70), and colony management (OR = 3.5, 95% CI 1.31–9.14). The lower level of colony infestation in adult bees and brood was measured as 1.97 ± 0.14 and 3.19 ± 0.25, respectively. Season, colony status, colony management, and agroecology were among the determinant factors of the level of varroa mite infestation in adult bees and brood. The results of the study demonstrated that honey production losses are largely attributable to V. destructor infestation. Therefore, it is critical to inform the community about the effects of V. destructor on honey production and develop and implement effective management strategies for this disease. In addition, further research should be done to identify and isolate additional factors that contribute to varroosis in honeybees in different regions.

Old strategies as modern solutions, shook swarming reduced Varroa destructor infestation rates of managed honey bee, Apis mellifera, colonies

Transferring adult honey bees from the combs of their hive to a new empty hive is a management strategy known as “shook swarming” that has been used by beekeepers in a variety of contexts since as early as 1796. Varroa destructor are dependent on mature brood to reproduce and shook swarming breaks the colony’s brood cycle by separating the adult bees from the brood developing in the old combs. We investigated the efficacy and practicality of shook swarming to mitigate negative health effects of Varroa in honey bee colonies by reducing Varroa infestation rates. New colonies were founded via traditional splitting or the shook swarm technique either with or without comb in the new hive. All colonies were given ∼1 month to establish and then assessed for foraging activity, colony strength, and Varroa infestation rate. We observed a significant decrease in the Varroa infestation rates of colonies that experienced shook swarming compared with those that had not. Colonies established via shook swarming had lower colony strength scores but maintained similar relative foraging activity as traditional splits. Our findings indicate that shook swarming is a viable, non-chemical control strategy for managing Varroa infestations and should be considered in long-term management plans where colonies undergo shook swarming aligned with honey production and/or pollination service delivery.

Effects of coumaphos on locomotor activities of different honeybee (Apis mellifera L.) subspecies and ecotypes

The effects of acute sublethal doses of coumaphos, an acaricide used against Varroa destructor infestation in beekeeping, on the locomotor activities of four native honeybee subspecies of Türkiye including two ecotypes (Carniolan honeybee -A. m. carnica, Syrian honeybee -A. m. syriaca, Caucasian honeybee- A. m. caucasica, and Muğla and Yığılca ecotypes of Anatolian honeybee A. m. anatoliaca) were investigated using an individual locomotor activity monitoring system. Analysis of locomotor activity data in the first 12-h, last 12-h, and 24-h time periods showed that bees from caucasica and carnica subspecies were not affected by coumaphos at all three acute doses (1, 2, and 5 μg coumaphos in 10 μl sucrose syrup for each bee). In contrast, bees from A. m. syriaca subspecies showed significantly elevated locomotor activity levels at 2 and 5 μg coumaphos doses within the first 12 h. Bees from both Muğla and Yığılca ecotypes of anatoliaca subspecies also showed elevated locomotor activity levels at 5 μg coumaphos dose but the magnitude of increase was lower in these ecotypes compared to that seen in syriaca subspecies in the first 12-h period. In general, increasing doses of coumaphos resulted in increased locomotor activity (locomotor activity), with differences in sensitivity across honeybee populations. Possible mechanisms underlying this variance and suggestions for further studies are discussed.

Health Status of Honeybee Colonies Differing in Genetic Intra-Colonial Diversity

Abstract Two different levels of diversity within a colony were compared for the prevalence of pathogens and diseases. Lower genetic diversity was obtained in the colonies in which the queens were inseminated with semen collected from drones originating from a single colony, while greater was obtained in the colonies with queens inseminated with semen from drones of thirty different colonies. Bees were tested for Varroa destructor infestation, microsporidia Vairimorpha spp. infection, acute bee paralysis virus (ABPV) and deformed wing virus (DWV). Colonies with a greater genetic diversity of workers in colonies were more infested with Varroa mites than genetically uniform colonies. Varroa infestation was not found to be associated directly with the weakening of bee colonies after winter. The two experimental groups had a similar number of colonies infected with Vairimorpha, and viruses. Intensity of Varroa infestation and Vairimorpha infection did not significantly affect the overwintering of bee colonies. Colonies in which DWV was detected significantly weakened during overwintering.

Varroa destructor infestation in honey bees in Ankara region, and antioxidant properties of produced honey

This study was undertaken to determine whether there was any correlation between the level of Varroa destructor infestation in honey bee samples collected from the Ankara region of Türkiye and the antioxidant contents of honey samples from those colonies. In terms of the severity of V. destructor infestation, the average percentage of infested bees in the first group was 16.06 ± 1.2%, the average percentage in the second group was 7.27 ± 0.71%, and the average in the third group was 1.69 ± 0.46%. Statistically significant differences were found between all honey samples collected from the three groups in terms of total phenolic contents and DPPH values. The total flavonoid levels in the honey samples taken from the third group were significantly higher than the values determined in the samples taken from the other two groups, while the ABTS and FRAP levels in honey samples from the first group were significantly higher than the values determined in samples from the other two groups. It was concluded that the total phenolic substances, total flavonoid contents, and DPPH, ABTS, and FRAP values of honey samples collected from these honey bee colonies changed in direct proportion to the severity of V. destructor infestation.

꿀벌응애류 방제용 개미산에 대한 조건별 기화량 평가

Honeybees are an important species influencing many aspects of human life, particularly economic and agriculture. Plant production depends upon pollination, and this is mainly enabled by honebees. Beekeepers across the Korea are experiencing unprecedented drops and losses in honeybee colonies. These losses have been attributed to bee mites (Varroa destructor and Tropilaelaps mercedesae) infestation. Application of acaricides is the most common practice to control bee mites. Among acaricides, formic acid is quite popular in Varroa mites control due to a natural substance with low residue levels in honey. However, beekeepers cannot use it without proper knowledge because it can cause significant harm to honeybees if used incorrectly. Therefore, this study was conducted to investigate how the vaporization rate of formic acid changes depending on the season in Korea.

Varroa destructor infestation levels in Africanized honey bee colonies in Brazil from 1977 when first detected to 2020

Varroa destructor infestation levels in Africanized honey bee colonies in Brazil from 1977 when first detected to 2020

The Epidemiological Situation of the Managed Honey Bee (Apis mellifera) Colonies in the Italian Region Emilia-Romagna.

Simple SummaryThe collapse of honey bee colonies is an important phenomenon worldwide. The individual and synergic actions of pathogens are one of the causes of this decline. Monitoring programs are essential to understand and prevent the epidemiological patterns that are involved. The present study aimed to investigate the health status of honey bees in the Emilia–Romagna region (northern Italy) during the year 2021, on workers from 31 apiaries. The prevalence and abundance of DWV, KBV, ABPV, CBPV, Nosema ceranae, and trypanosomatids (Lotmaria passim, Crithidia mellificae, Crithidia bombi) were investigated four times in the year using molecular methods. Trypanosomatids were not found in any of the samples, while DWV, CBPV and N. ceranae were the most prevalent pathogens. Pathogens had different peaks in abundance over the months, showing seasonal trends related to the dynamics of both bee colonies and Varroa destructor infestation. The results of this study suggest that the monitoring program could be useful to understand the dynamics of honey bee pathogens.The recent decades witnessed the collapse of honey bee colonies at a global level. The major drivers of this collapse include both individual and synergic pathogen actions, threatening the colonies’ survival. The need to define the epidemiological pattern of the pathogens that are involved has led to the establishment of monitoring programs in many countries, Italy included. In this framework, the health status of managed honey bees in the Emilia–Romagna region (northern Italy) was assessed, throughout the year 2021, on workers from 31 apiaries to investigate the presence of major known and emerging honey bee pathogens. The prevalence and abundance of DWV, KBV, ABPV, CBPV, Nosema ceranae, and trypanosomatids (Lotmaria passim, Crithidia mellificae, Crithidia bombi) were assessed by molecular methods. The most prevalent pathogen was DWV, followed by CBPV and N. ceranae. Trypanosomatids were not found in any of the samples. Pathogens had different peaks in abundance over the months, showing seasonal trends that were related to the dynamics of both bee colonies and Varroa destructor infestation. For some of the pathogens, a weak but significant correlation was observed between abundance and geographical longitude. The information obtained in this study increases our understanding of the epidemiological situation of bee colonies in Emilia–Romagna and helps us to implement better disease prevention and improved territorial management of honey bee health.

Hygienic Behavior of Apis mellifera and Its Relationship with Varroa destructor Infestation and Honey Production in the Central Highlands of Ecuador.

Simple SummaryThe honey bee (Apis mellifera) is an insect that has a relevant role in natural and agricultural ecosystems due to its leading role in the pollination of crops that are part of humanity’s food chain. Even in the face of the modernization and the intensification of agriculture, the honey bee has maintained its economic importance due to the value generated by its products. At present, when attempting to improve the characteristics of bees, it is important to evaluate variables such as hygienic behavior, Varroa infestation rates, and honey production as a basis for improvement plans in search of increasing productive yields at altitudes 2600 m above sea level (m.a.s.l.). The strength of bees against parasites, and therefore the better development of their colonies, was determined, resulting in a healthy colony with an increase in honey production. The altitude and the hygienic behavior of bees in the central highlands showed an inverse relationship. There was no relationship between infestation rates and production; it is proposed that environmental factors do not modulate Varroa levels or honey production.The aim of this research was to analyze the relationship among hygienic behavior (HB), Varroa destructor infestation, and honey production in the central highlands of Ecuador. Overall, 75 honey bee colonies were evaluated before, during, and after production at three altitude levels (2600–2800, 2801–3000, and >3000 m.a.s.l.). The hygienic behavior percentage of the colonies was determined by the pin-killing method, and the colonies were classified into three groups: high HB (>85%), mid HB (60.1–85%), and low HB (≤60%). Varroa infestation was diagnosed as well, and honey production was evaluated only during production. HB was high and heterogeneous, averaging 80% ± 9.7%. Its highest expression was observed at lower altitudes. The infestation degree was low (3.47% ± 1.56%), although the mite was detected in all colonies upon sampling. A negative correlation was observed between HB and Varroa infestation in the first sampling (−0.49 **), suggesting that the high- and mid-altitude HB colonies underwent the lowest infestation rates, regardless of sampling. The correlations between HB and production were significant (0.26 *), indicating a positive effect of HB on production, meaning that colonies with high HB obtained the highest honey production (25.08 ± 4.82 kg/hive). The HB of bees showed an inverse relationship with altitude and it tended to reduce the effect of Varroa infestation, favoring honey production and, thus, suggesting the feasibility of selecting colonies with high HB.

Efficacy and Toxicity of VarroMed® Used for Controlling Varroa destructor Infestation in Different Seasons and Geographical Areas

VarroMed® is a soft acaricide registered for honey bees on the European Union market since 2017 for Varroa control. Researchers involved were partners of different countries of the Varroa control task force of the COLOSS Association. Our goal was to evaluate performances (acaricide efficacy and toxic effects on honey bees) of VarroMed® in different climatic conditions. Our results in the tested apiaries showed an efficacy ranging from 71.2 to 89.3% in summer/autumn, and from 71.8 to 95.6% in winter. No toxic effects on bees were observed, except in one apiary, where severe cold climatic conditions played a crucial role. The treatment could be efficiently applied in broodright as well as in broodless colonies. Integrated pest management (IPM) recommendations for beekeepers are provided in order to apply the best Varroa control protocol.

Counting phoretic Varroa destructor mites dislodged from honey bees (Apis mellifera) sampled under the escape board: a simple, precise and rapid method

In order to control infestation of the parasitic mite Varroa destructor infestation, it is essential to determine mite density in a colony. In daily practice, the beekeeper needs a simple, reproductive, safe and fast method. We have developed a new technique of sampling under the escape board to count dislodged mites from bees and compared it with the measure on brood - which is considered as the "Gold Standard." On average, the number of mites measured under the escape board was 60% lower compared to the number of mites measured on brood and the ratio escape board/brood was proportional to the number of mites counted on brood with a narrow dispersion around the predicted value (the 95% limits of agreement around the bias were ± 23%). This new method is simple, rapid and safe, inasmuch as dislodging and counting mites from sampled bees can be performed later on.

Genetic Parameters of Honey Bee Colonies Traits in a Canadian Selection Program.

Simple SummaryGenetic selection is still little applied to honey bees (Apis mellifera), whose complex genetic and reproductive characteristics are a challenge to model statistically. The aim of this project was to determine the genetic parameters of several traits important for Canadian beekeepers with a view to establishing a breeding program in a northern context. Our results show that the five traits studied (i.e., honey production, spring development, winter consumption, hygienic behavior and Varroa destructor infestation) are all heritable. Furthermore, the genetic correlations between these traits are all positive or null, which means that these traits can be selected simultaneously in a honey bees genetic selection program. Our results are instrumental to the development of a selection index that can be used to improve the capacity of honey bees to thrive in northern conditions.Genetic selection has led to spectacular advances in animal production in many domestic species. However, it is still little applied to honey bees (Apis mellifera), whose complex genetic and reproductive characteristics are a challenge to model statistically. Advances in informatics now enable creation of a statistical model consistent with honey bee genetics, and, consequently, genetic selection for this species. The aim of this project was to determine the genetic parameters of several traits important for Canadian beekeepers with a view to establishing a breeding program in a northern context. Our results show that the five traits measured (Varroa destructor infestation, spring development, honey production, winter consumption, and hygienic behavior) are heritable. Thus, the rate of V. destructor infestation has a high heritability (h2 = 0.44 ± 0.56), spring development and honey production have a medium heritability (respectively, h2 = 0.30 ± 0.14 and h2 = 0.20 ± 0.13), and winter consumption and hygienic behavior have a low heritability (respectively, h2 = 0.11 ± 0.09 and h2 = 0.18 ± 0.13). Furthermore, the genetic correlations between these traits are all positive or null, except between hygienic behavior and V. destructor infestation level. These genetic parameters will be instrumental to the development of a selection index that will be used to improve the capacity of honey bees to thrive in northern conditions.