Control Hives Research Articles

Hypergravity Impact on Fertility of Apis mellifera carnica Queens – Case Study

The launch is considered the most stressful rocket flight stage due to the hypergravity occurrences. The possibility of using honey bees (Apis mellifera) as the extraterrestrial pollinator depends on their ability to reproduce correctly after experiencing hypergravity. The described study aims to verify the impact of a launching rocket’s acceleration on honey bee queen’s egg-laying behavior. Four artificially inseminated A. mellifera carnica queens were placed in the Human Training Centrifuge and given to the acceleration pattern of the launching Soyuz rocket. Next, the data on the number of food stores, eggs, larvae, and worker and drone pupae were collected from the test and control hives using the modified Liebefeld method. The pilot study results imply that accelerated queen’s egg-laying behavior may change twofold: limiting or maximizing the number of laid eggs, with the control queen egg-laying rate remaining stable for all samples. The number of drone pupae is greater for the test sample colonies, with its earlier appearance in the hive. No impact on overwintering success was observed. Authors indicate limitations of the results and a need to continue the study to verify the occurrence of anomalies potentially related to the examined factor.

Effect of Improved Hive Cover Designs on Internal Microclimate and Colony Establishment of West African Honeybees (Apis mellifera adansonii L.) in Awka, Nigeria

Hive cover designs majorly affects the microclimate and colony establishment of African honeybee colonies in Nigeria. It became pertinent therefore to assess the effect of modified hive cover designs on the internal microclimate and colony establishment of West African honeybee (Apis mellifera adansonii L.) Colonies in Awka, Nigeria. Four insulating materials were used to construct the covers of twelve modified frame bar hives and designated: Control (plywood); T1 (warped boards); T2 (PVC) and T3 (foam). Each hive treatment was replicated three times. Data on ambient and hive microclimate as well as the colonization of honeybees’ colonies were observed and reported. The results indicated that the control had the highest temperature (31.86 ºC) while T1 (30.40ºC) had the least. The hive temperature was higher in March, 2023 (32.72°C) while August (29.87°C) had the least. The highest relative humidity (73.18%) was recorded in T1 while the control had the least (64.38%). The hive temperature and relative humidity was significantly affected by hive cover designs and different months of the study period (P<0.05). The highest colonization by African honeybees was observed in the control (100%) but none occurred in T2 (0.00%). Colonization of the Control hives occurred in July, October, and November, 2022 while that of T1 and T3 occurred in December, 2022. Colony establishment of African honeybees was not significantly affected by hive cover designs (p=0.26) and different months of the study period (p=0.24). It was concluded that beekeepers should adopt the insulation of hiver covers with plywood wood since it had 100% colonization of West African honeybees’.

Stingless bee (Tetragonula carbonaria) foragers prioritise resin and reduce pollen foraging after hive splitting

Stingless bees are increasingly in demand as pollinators in agricultural crops within the tropics and subtropics. Hive splitting, where one strong managed hive is “split” into two independent daughter colonies, is commonly used to increase hive numbers. However, how splitting impacts foraging behaviour or the time taken for the colony to recover from splitting has not previously been studied. We assessed the impact of splitting on the foraging behaviour of Tetragonula carbonaria colonies. The number of returning forager trips and foraged proportions of pollen, nectar and resin was observed after splitting and compared with unsplit control hives over a 31-day period. We found the total amount of returning foragers in split hives reduced to less than a third of unsplit hives (unsplit median, 184–288; split median, 19–61) for 16 days, while returning nectar (unsplit median, 89–147; split median, 16–28) and pollen (unsplit median, 55–155; split median, 1–7) foragers reduced to less than a quarter of unsplit hives for 9 days following splitting. After 31 days, the number of total, nectar and pollen foraging trips had still not recovered to levels observed in unsplit hives. Resin foraging trips however were not significantly different to unsplit hives after only 10 days. The colony foraging allocation to resin (proportion) increased after splitting and was significantly higher in split hives until day 16 of the experiment (unsplit median, 0.03–0.05; split median, 0.10–0.16). Our results demonstrate that split colonies prioritise resin collection and foraging on floral resources is reduced. We recommend that hives should not be split within 31 days of being used for pollination, and resin sources should be conserved where possible and supplemented where necessary due the vital roles of the resource.

Management practice for small hive beetle as a source of microplastic contamination in honey and honeybee colonies

Microplastics (MP) have emerged as a widespread environmental contaminant affecting bee health. In this study we report on the impact of one of the cultural practices used to control the small hive beetle (SBH, Aethina tumida). Management of the beetle often includes the use of in-hive traps of different kinds, such as non-woven microfiber wipes. When placed inside the hive, bees chew on these wipes, which then become fuzzy and fray to the point where beetles become entangled in their fibers. The current study aimed to examine the composition of these microfiber sheets and to evaluate whether their use resulted in unintended MP contamination of bees and honey. We treated hives with one blue microfiber sheet placed on top of the frames for at least three months. After that time, we collected adult bees and honey samples from treated hives, control hives in the same apiary (control near), and control hives in an apiary 7.5 km away (control far). Honey from treated hives had a significantly greater number of blue MF than honey from the control hives (mean ± SD, treatment 11.83 ± 3.76, control near 2.25 ± 0.92 and control far 0.25 ± 0.5 MF/20 gr honey). Also, hives treated with the microfiber sheets had a significantly greater number of blue microfibers in the gut and cuticle of bees, than the control hives located in a different apiary. However, the control and treated bees located in the same apiary had a similar number of blue microfibers (mean ± SD, treatment 4.7 ± 2.28, control near 3 ± 1.63 and control far 0.5 ± 0.58 MF in 20 bees). Thus, the current study raises concerns of the use of microfibers sheets to trap the SBH as it results in the incorporation of microfibers into the ecosystem and the food chain.

The organizational impact of chronic heat: diffuse brood comb and decreased carbohydrate stores in honey bee colonies

Insect pollinators are vital to the stability of a broad range of both natural and anthropogenic ecosystems and add billions of dollars to the economy each year. Honey bees are perhaps the best studied insect pollinator due to their economic and cultural importance. Of particular interest to researchers are the wide variety of mechanisms honey bees use for thermoregulation, such as fanning cool air currents around the hive and careful selection of insulated nest sites. These behaviors help honey bees remain active through both winter freezes and summer heatwaves, and may allow honey bees to deal with the ongoing climate crisis more readily than other insect species. Surprisingly, little is known about how honey bee colonies manage chronic heat stress. Here we provide a review of honey bee conservation behavior as it pertains to thermoregulation, and then present a novel behavior displayed in honey bees—the alteration of comb arrangement in response to 6 weeks of increased hive temperature. We found that while overall quantities of brood remained stable between treatments, brood were distributed more diffusely throughout heated hives. We also found that heated hives contained significantly less honey and nectar stores than control hives, likely indicating an increase in energy expenditure. Our results support previous findings that temperature gradients play a role in how honey bees arrange their comb contents, and improves our understanding of how honey bees modify their behavior to survive extreme environmental challenges.

Testing of the Efficacy of Bee Probiotic Lactobacilli Under In Vivo Conditions

Abstract American foulbrood is amongst the most dangerous diseases of the bee-family affecting many honeybee colonies worldwide. In countries of European Union, based on veterinary legislation, the bee colonies tested positive to American foulbrood are eradicated with high economic losses. It is therefore necessary to look for effective prevention, especially by the using of natural ingredients such as probiotics. In this study, we used lactobacilli isolated from digestive tracts of adult healthy honey bees and selected based on their good probiotic properties and ability to inhibit the growth of Paenibacillus larvae. These isolates were identified as Lactobacillus brevis and Lactobacillus plantarum. Night cultures of both strains were used for the preparation of probiotic suspensions and pollen was selected as an appropriate carrier for application of probiotic lacto-bacilli to the hives. Half a litre of pollen suspension was prepared for each hive. The suspension for experimental hives contained probiotic lactobacilli in concentration of 107–108 CFU.ml−1. Bees in control hives received pollen suspension without addition of probiotic lacto-bacilli. The suspensions were supplied to bees three times, once a week. Before and during administration of probiotics, samples of honey bees from each hive were taken every week and numbers of lactobacilli, P. larvae, enterobacteria and coliform bacteria were determined in their digestive tracts. Four weeks after the first administration of probiotic-pollen solution the numbers of lactobacilli were increased approximately by 0.5 log. Before starting this experiment, P. larvae (approx. 107 CFU.ml−1) were detected in digestive tracts of honey bees. In the experimental group after 3 weeks and in the control group after 4 weeks, no viable counts of P. larvae were found. The numbers of enterobacteria, coliform bacteria and Bacillus sp. decreased in both groups. During the experiment the health and condition of the hives were monitored. In addition, also monitored were: the development of the bee colony, the number of dead bees, the amount of hive debris, the aggressiveness of the bees, and the amount of honey spun; later during the autumn treatment also the fall of Varroa jacobsoni was noted. In the experimental and control groups, we recorded a decrease in the amount of hive debris. Only in the experimental group was a slightly above-average development of the bee colony, slightly above-average honey yields and a 70 % lower drop of Varroa mites. Based on these results, we assumed that the probiotic-pollen solution had a positive influence on the composition of microbiota in bee digestive tracts and it can increase resistance to P. larvae. It also had a positive effect on the health and condition of the bee colony. Probiotic-free pollen solution showed similar but weaker effects.

Development of an automatic solar powered honey bee feeding system in a movable multi shelves apiary

Keeping bee colonies is one of the most important sectors of investment in the global agricultural field. Internationally, beekeepers are interested in improving bee feeding methods to maximize the productivity and quality of their products. Whereas the current study aims to develop and evaluate an automatic feeding system that works with solar energy. This technique increases the vertical expansion of beekeeping by designing a multi-shelf mobile apiary for easy transportation as desired. The development process included the inclusion of automated feeders that operate electronically using sensors to provide a nutritional solution for bee colonies without human intervention. Also, the automatic apiary was provided with a sugar solution tank that was equipped with a continuous stirring system that works with a timer. Also, the automatic apiary contains an alarm system and remote mobile contact with the beekeeper in case of depletion of the sugar syrup. The variables under study included three levels of nutritional level volumes of 500, 750, and 1000 ml, respectively, with two stirring periods (3 and 6 times/day) at two concentrations for sugar solution of 50 and 67%. The evaluation process was done during the critical winter period of the year, from December to March. The main results showed that the colonies’ strength had an increment ratio over control hives of 30.23% when using the highest variable levels. Also, the seasonal energy consumption ranged from 1.25–2.81 kWh per season. Therefore, beekeepers can benefit from this novel feeding approach.

Effects of Varroa destructor on Hemolymph Sugars and Secondary Infections in Honeybees (Apis mellifera)

The European honeybee contributes to the agriculture by its pollination; however, the overwintering loss rate over the last decades is worrisome. Varroa destructor is considered one of the most important causes of bee colony declines. This project aims to correlate the infestation by varroa to the hemolymph sugar concentrations and bacterial and viral coinfections. Six highly infested and six control hives were compared over time. Pooled hemolymph samples from honeybees were collected for sugar concentration measurements using a previously validated portable glucometer. The hemolymph samples were submitted for bacteriology. Multiplex RT-PCR analysis was performed on honeybees for six viruses: DWV-A, DWV-B, BQCV, ABPV, KBV, and IAPV. There was also no predominance of pathogenic bacteria. In September, sugar concentrations in hemolymph were significantly lower in highly infested hives than in control hives. Infested hives showed markedly higher viral loads except for ABPV. DWV-A and BQCV viral loads from highly infested hives were significantly higher in September compared to July. A continued and severe exposure to varroa leads to increased viral charges and decreased sugar concentrations, suggesting alterations in immunity, metabolism, and reserve mobilization. These parameters contribute to the weakening and mortality of the colonies.

Влияние погодных условий на медосбор в период цветения липы мелколистной в Удмуртской Республике

The study results of honey-leaf stands productivity in the Udmurt Republic, belonging to the area of the southern taiga forests of the taiga zone of the European part of the Russian Federation, are presented. Based on the data obtained at the accounting apiaries and control hives, the change in the honey weight gain was revealed depending on the weather conditions, the composition coefficient and the age of the linden stand.

Proteomic profiling of royal jelly produced by Apis mellifera L. exposed to food containing herbicide-based glyphosate

Royal jelly (RJ) is rich in protective elements associated with collective immune defenses in the hive of Apis mellifera. Exposure of bees to glyphosate-based herbicides causes ultrastructural changes in the hypopharyngeal glands and a reduction in the production of RJ. However, the effects of glyphosate-based herbicides on the protein composition of RJ and consequences for the hive are unknown. Thus, we performed proteomic profiling of royal jelly produced in hives of A. mellifera exposed to food containing 1,5 μL of Roundup® (2.16 mg. g−1 of glyphosate). The production of RJ was carried out in six hives, following the method of artificial production of queens. The combs containing 80 grafting cells were introduced into the hives, and the collection of royal jelly was performed after 72 h. Two treatments were determined based on hive feeding and the hive as the experimental unit: Control and “Roundup®”. Royal jelly from the Roundup® treatment hives was compared to the Control hives. Proteins with differences in expression were identified by mass spectrometry. Only the proteins present in all three biological replicates were considered in the differential abundance analysis, using Student's t-test (p-value < 0.05, two-tailed). Hives that received food containing Roundup®, analysis showed alterations in protein profile in the RJ produced therein. In total, 24 proteins were identified, and the accumulation of Major royal jelly protein 3 (MRJP3) was downregulated, showing a significant reduction in hives exposed to food containing Roundup® in relation to control hives (t = 0.0017). MRJP3 acts analogously to polyclonal antigen-antibody reactions, performing functions related to immunity in bees of different ages and castes. To the best of our knowledge, this is the first study to demonstrate changes in the proteomic profile of RJ caused by glyphosate-based herbicides, indicating its negative effects on the nutrition and social immunity of bees.

The use of cork in the thermoregulation of the hive: an innovation attempt to enhance non-wood products and beekeeping in Mediterranean forests

Hive thermoregulation is fundamental for the normal development of bee colonies and, consequently, hive productivity and honey bee health. External conditions mainly affect the walls of the hive. Therefore, hive construction materials and thermal conductivity features can influence its thermoregulation efficiency. The present trial made a comparison of experimental hives (modified Dadant-Blatt of 10 frames) made with cork as thermal insulator and conventional hives made entirely with firwood to evaluate their effects on thermoregulation of Apis mellifera ligustica colonies in Northwerstern Sardinia (Italy). The cork-modified beehives consisted of common conventional beehives modified by replacing the wooden walls with cork walls (pressed cork), whereas the control beehives (wooden hives) consisted of standard Dadant Blatt beehives entirely made of firwood. Environmental (especially nest internal temperature) parameters were assessed periodically. The daily temperature pattern of cork-modified beehives was more regular than that of control beehives. In addition, bees had a more efficient winter thermoregulation in cork-modified beehives compared with control hives.

Simulating Honey Bee Large-Scale Colony Feeding Studies Using the BEEHAVE Model-Part I: Model Validation.

In pesticide risk assessments, semifield studies, such as large‐scale colony feeding studies (LSCFSs), are conducted to assess potential risks at the honey bee colony level. However, such studies are very cost and time intensive, and high overwintering losses of untreated control hives have been observed in some studies. Honey bee colony models such as BEEHAVE may provide tools to systematically assess multiple factors influencing colony outcomes, to inform study design, and to estimate pesticide impacts under varying environmental conditions. Before they can be used reliably, models should be validated to demonstrate they can appropriately reproduce patterns observed in the field. Despite the recognized need for validation, methodologies to be used in the context of applied ecological models are not agreed on. For the parameterization, calibration, and validation of BEEHAVE, we used control data from multiple LSCFSs. We conducted detailed visual and quantitative performance analyses as a demonstration of validation methodologies. The BEEHAVE outputs showed good agreement with apiary‐specific validation data sets representing the first year of the studies. However, the simulations of colony dynamics in the spring periods following overwintering were identified as less reliable. The comprehensive validation effort applied provides important insights that can inform the usability of BEEHAVE in applications related to higher tier risk assessments. In addition, the validation methodology applied could be used in a wider context of ecological models. Environ Toxicol Chem 2020;39:2269–2285. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Control of Varroa destructor development in Africanized Apis mellifera honeybees using Aluen Cap (oxalic acid formulation)

ABSTRACT Aluen Cap is an oxalic acid (OA) formulation that shows promise as a control method for Varroa destructor. This work explores the use and efficacy of Aluen Cap against V. destructor in Africanized honeybees in Veracruz Mexico, where capped brood is always present across the year and acaricide resistance was a problem. Twenty-four beehives were assessed over 42 days, a period of time associated with the liberation of OA from Aluen Cap. The acaricide formulation shows significantly higher mean efficacy (92.1%) than control hives (36.5%). This test suggests the high value of the new oxalic acid formulation in AHBs despite the high temperatures and presence of brood, avoiding the necessity of multiple applications of OA, hence simplifying colony management.

Effectiveness of control strategies for Varroa jacobsoni and Tropilaelaps mercedesae in Papua New Guinea.

Apiculture in the Pacific island country of Papua New Guinea (PNG) is under significant pressure from emerging parasitic mites, Varroa jacobsoni and Tropilaelaps mercedesae. Although numerous mite control products exist, beekeepers in PNG have limited resources and access to these products and their effectiveness under local conditions is untested. Here we determined the effectiveness of two brood manipulation strategies-queen caging and queen removal-for managing V. jacobsoni and T. mercedesae in comparison to the chemical miticide Bayvarol®. Our results found Bayvarol was the most effective control strategy for V. jacobsoni, maintaining high efficacy (> 90%) over 4 months with significantly reduced levels of V. jacobsoni compared to untreated control hives. In contrast, T. mercedesae were significantly reduced by the brood manipulation strategies over 2 months, but not significantly by Bayvarol compared to the controls. These results highlight that a combination of strategies is likely needed to effectively manage both mite pests in PNG. We discuss how these findings are relevant to informing best practice for honey bee biosecurity and how these strategies can be implemented to improve the effectiveness of mite management for PNG beekeepers.

Bystander Phage Therapy: Inducing Host-Associated Bacteria to Produce Antimicrobial Toxins against the Pathogen Using Phages.

Brevibacillus laterosporus is often present in beehives, including presence in hives infected with the causative agent of American Foulbrood (AFB), Paenibacillus larvae. In this work, 12 B. laterosporus bacteriophages induced bactericidal products in their host. Results demonstrate that P. larvae is susceptible to antimicrobials induced from field isolates of the bystander, B. laterosporus. Bystander antimicrobial activity was specific against the pathogen and not other bacterial species, indicating that the production was likely due to natural competition between the two bacteria. Three B. laterosporus phages were combined in a cocktail to treat AFB. Healthy hives treated with B. laterosporus phages experienced no difference in brood generation compared to control hives over 8 weeks. Phage presence in bee larvae after treatment rose to 60.8 ± 3.6% and dropped to 0 ± 0.8% after 72 h. In infected hives the recovery rate was 75% when treated, however AFB spores were not susceptible to the antimicrobials as evidenced by recurrence of AFB. We posit that the effectiveness of this treatment is due to the production of the bactericidal products of B. laterosporus when infected with phages resulting in bystander-killing of P. larvae. Bystander phage therapy may provide a new avenue for antibacterial production and treatment of disease.

Impact of beneficial bacteria supplementation on the gut microbiota, colony development and productivity of Apis mellifera L.

Honey bees are important pollinators of several crops and ecosystems, having a great ecological and economic value. In Europe, the restricted use of chemicals and therapeutic agents in the beekeeping sector has stimulated the search for natural alternatives with a special focus on gut symbionts. The modulation of the gut microbiota has been recognised as a practical and successful approach in the entomological field for the management of insect-related problems. To date, only a few studies have investigated the effect of bacterial supplementation on the health status of colonies, colony productivity and gut symbionts. To this purpose, a preparation of sugar syrup containing bifidobacteria and lactobacilli isolated from bee gut was sprayed on the frames of an apiary located in open field once a week for four weeks. Treated and control hives were monitored for two months for brood extension, honey and pollen harvest. The presence of beneficial gut microorganisms within bee gut was investigated with denaturing gradient gel electrophoresis and next generation sequencing. The administered bacteria led to a significant increase of brood population (46.2%), pollen (53.4%) and harvestable honey in honey supers (59.21%). Analysis of the gut microbiota on the new generation of bees in treated hives showed an increase in relative abundance of Acetobacteraceae and Bifidobacterium spp., which are known to be involved in bee nutrition and protection.

Honey yield of different commercial apiaries treated with Lactobacillus salivarius A3iob, a new bee-probiotic strain.

The main objective of this study was to determine the impact of Lactobacillus salivarius A3iob, a honey bee gut-associated strain (GenBank code access KX198010), on honey yield. Independent assays were conducted from May to September 2014 and 2015, in three commercial apiaries: Tilquiza, El Carmen and Yala, all located in north-western Argentina. Local Apis mellifera L. bees were kept in standard Langstroth hives; treated hives were fed once a month with 1×105 cfu/ml viable Lactobacillus cells, administered to the bees through a Doolittle-type feeder in 125 g/l sucrose syrup. Control hives were only given the syrup mixed with MRS sterile broth. The main honey harvest was done in December in all groups and we found that there was an overall increase in honey yield from the treated hives. In 2014, all treated hives produced between 2.3 to 6.5 times more honey than the controls. However, in 2015, higher honey average yields in the treated hives at El Carmen and Yala were obtained, yet not at Tilquiza, because of a slight mishap. They experienced the swarming of several bee colonies due to a higher number of bees without appropriate management, which caused the control group to yield more honey compared to the hives fed with Lactobacillus. Interestingly, at El Carmen, two honey harvests were recorded: one in winter and another in summer (July and December 2015, respectively). This unexpected result arose from the particular flora of the region, mainly Tithonia tubaeformis, which blooms in winter. L. salivarius A3iob cells prove to be a natural alternative that will positively impact the beekeepers' economy by providing a higher honey yield.

Effect of pollen traps on the relapse of chronic bee paralysis virus in honeybee (Apis mellifera) colonies

Pollen traps are used by beekeepers to collect pollen harvested by honeybees. Here, we set up an experiment to evaluate whether pollen traps are a risk factor involved in the development of the chronic bee paralysis, a viral honeybee disease affecting adult bees and transmitted by contact. After a recent episode of chronic bee paralysis in an apiary, pollen traps were installed on three hives while two hives without pollen traps were used as control. During the experiment, the chronic bee paralysis virus (CBPV) loads in foragers from the control hives remained lower than 108 equivalent copies of CBPV genome per bee but were higher than 1010 equivalent copies of CBPV genome per bee in the many symptomatic bees and in the hundreds of dead bees found in front of trap hives. Clinical signs of the disease persisted for 3 weeks at the entrance of the trap hives. These signs disappeared after the pollen traps were removed, accompanied by a decrease in the viral loads in foragers. Despite the small number of colonies examined, the results of this study suggest the impact of pollen traps on the relapse of chronic paralysis outbreaks in colonies infected by CBPV.

Bacteriophages as an alternative to conventional antibiotic use for the prevention or treatment of Paenibacillus larvae in honeybee hives.

American Foulbrood (AFB) is an infectious disease caused by the bacteria, Paenibacillus larvae. P. larvae phages were isolated and tested to determine each phages' host range amongst 59 field isolate strains of P. larvae. Three phages were selected to create a phage cocktail for the treatment of AFB infections according to the combined phages' ability to lyse all tested strains of bacteria. Studies were performed to demonstrate the safety and efficacy of the phage cocktail treatment as a replacement for traditional antibiotics for the prevention of AFB and the treatment of active infections. Safety verification studies confirmed that the phage cocktail did not adversely affect the rate of bee death even when administered as an overdose. In a comparative study of healthy hives, traditional prophylactic antibiotic treatment experienced a 38±0.7% decrease in overall hive health, which was statistically lower than hive health observed in control hives. Hives treated with phage cocktail decreased 19±0.8%, which was not statistically different than control hives, which decreased by 10±1.0%. In a study of beehives at-risk for a natural infection, 100±0.5% of phage-treated hives were protected from AFB infection, while 80±0.5% of untreated controls became infected. AFB infected hives began with an average Hitchcock score of 2.25 out of 4 and 100±0.5% of the hives recovered completely within two weeks of treatment with phage cocktail. While the n numbers for the latter two studies are small, the results for both the phage protection rate and the phage cure rate were statistically significant (α=0.05). These studies demonstrate the powerful potential of using a phage cocktail against AFB and establish phage therapy as a feasible treatment.

The effect of thyme (Thymus caucasicus) ethanol extract on Varroa mite (Varroa destructor), an ectoparasite mite of Apis mellifera meda (Hym: Apidae)

Chemical control of the Varroa mite (Varroa destructor), which is one of the most important pests of honey bees, is practiced on a worldwide scale. However, because of abundant use of different acaricides, the mites have become resistant to many of them. We chose to apply non-synthetic chemicals for control of Varroa mites by using thyme (Thymus caucasicus) ethanol extract on honey bees. In September-October 2013, we collected wild thyme growing in Kurdistan mountains, ground it, and its ethanol extract was made by using 95% ethylic alcohol. We used a randomized complete design with ten treatments of different concentrations of ethanol extract of thyme as a statistical model and one control with pure 95% ethanol with four replications. The interior temperature of the brood chamber was measured to be 30 ± 1°C, and the ambient temperature surrounding them was 33 ± 2°C. We sprayed the extracted thyme solution on honey bees and counted the number of dead mites by picking them out from the bottom board of each hive at every 12 h, 24 h, and 48 h intervals after spraying. The results showed that the use of the thyme extract influenced significantly the percentage of mortality of dead mites in the extract-sprayed treatment and the control treatment. The percentage of mortality of the honey bees in control hives and the honey bees treated by thyme ethanol extract did not have a significant difference. Results of our experiment using ethanol extract of thyme showed that its use in hives was safe without a high risk of mortality for honey bees.