Foulbrood Research Articles

Exploring network governance in sustainable beekeeping management in the Mekong subregion and its challenges

This research paper aims to explore a network governance in sustainable apiculture management and identify its challenges to government and non-governmental policy makers. Qualitative data was collected through participant observation during field visits and Focus Group Discussions (FGDs) with regional apiculture management. The research results show that each country in the Mekong subregion has different network governances in supporting a sustainable apiculture management. Some countries have a collaborative network between the government, the civil society, entrepreneurs, and scholars. In contrary, some countries lack a policy framework from the government. This difference becomes challenges for the six governments of the Mekong subregion countries to commonly support the sustainable apiculture management in the subregion. The identified challenges in the paper are: (1) a capacity gap between the six countries of the region; (2) no common policies and regulations that would facilitate local beekeepers’ access to wider regional bee products; (3) no support for inter-regional transport of bees and honey for academic purposes; (4) inadequate native bee species preservation and pesticides use; (5) local beekeepers’ limited access to a regional bee diseases and pesticides use database; and, (6) a lack of regional standards for general honeybee product support.

In vivo and Laboratory Studies of Tetracycline Prevention of Foulbrood disease of Apis cerana indica Fab. and its Effects on Honey

Laboratory and field studies were carried out to assess the efficacy of the antibiotic tetracycline in preventing and managing American foulbrood (AFB) and European foulbrood (EFB) diseases in honey bees. Experiments with immature worker bees in the laboratory demonstrated that honey bee larvae could endure a broad range of antibiotic doses in their diet. The recommended dose of tetracycline (100 μg/ml) effectively protected young larvae from infection. However, once the dose exceeded this recommended level, it reached a point where it became lethal.

Study of the chemical composition of the essential oil derived from Thymus lancéolatus desf, an endemic aromatic plant native from Algeria and evaluation of its efficacy against Paenibacillus larvae and Ascosphaera Apis, two diseases affecting the honeybees, Apis mellifera

The essential oil and hydrolate of Thymus lancéolatus desf, an endemic aromatic plant native to the mountains of northwestern Algeria, were tested in vitro for their antimicrobial activity against the bacteria Paenibacillus larvae, the causative agent of American foulbrood, and the fungi Ascosphaera apis, the responsible agent of chalkbrood disease in honeybees, Apis mellifera. The oil was extracted from various aerial parts of the plant using steam distillation. It shows high efficacy against both diseases, while its hydrolat demonstrates high efficacy against A.apis alone. The lethal doses (LD100) of the fungi were estimated at 0.034% and 25.30% for the essential oil and the hydrolat, respectively. The estimated concentration of the DL100 bacteria was 17.37 ul/Disc of EO. The hydrolate had no effect on P. larvae. This exceptional double efficacy of T.lancéolatus desf EO has been attributed to its particular active compound, Durenol, which constitutes 34.8% of the oil and the high quantities of its precursors (γ-Terpinene (16.71%) and Sylvestrene (15.17%) contribute to its effectiveness. Also, the abcence of acetate compound further enhances its efficacy. EO of Thyme was proven to be the most effective essential oil in vitro against P. larvae and A. apis, making it an excellent natural alternative to antibiotics.

Seasonal detection of pathogens in honeybees kept in natural and laboratory conditions

The honeybee is one of the most important pollinators in the world. The frequently observed poor health of honeybee colonies can be caused by various factors, e.g. environmental pollution, nutritional stress, and climate changes. Moreover, honeybees are constantly exposed to a wide spectrum of pathogens, such as parasites, bacteria, and viruses. We examined the occurrence of various diseases in different-aged worker honeybees from two colonies kept in natural and laboratory conditions during spring, summer, and autumn in Poland. The honeybees were examined by PCR to detect infection with selected pathogens: Nosema ceranae, N. apis, N. bombi, Acarapis woodi, trypanosomatids, and neogregarines (Mattesia or Apicystis species) and by RT-PCR to identify deformed wing virus (DWV), black queen cell virus (BQCV), and acute bee paralysis virus (ABPV). DWV and N. ceranae turned out to be the dominant pathogens. Trypanosomatids and BQCV were also found in several samples. We did not detect the presence of the other pathogens: N. apis, N. bombi, A. woodi, neogregarines, or ABPV. As shown in the present study, the dynamics and occurrence of pathogens are influenced by keeping conditions, honeybee age, and seasonality.

Environmental Biomonitoring of Heavy and Toxic Metals Using Honeybees and Their Products—An Overview of Previous Research

Humans and bees share millennia of history that have resulted in ever-increasing connection and interdependence. Thus, today, it is impossible to ignore the influence of humans on bees, particularly regarding the decrease in their numbers due to environmental contamination. Although they do not cause immediate mortality, heavy and toxic metals, along with dangers such as bee diseases, pesticides, habitat destruction, and climate change, threaten the number of bees and should not be ignored. Honeybees, their colonies, and their products are recognized as accumulators of metals and biological indicators of the presence of these metals in all environmental components. This study is an overview of prominent research from the past three decades on heavy and toxic metal levels in honeybees (Apis mellifera L.), honey, wax, and pollen. This research compares metals such as Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn in natural environments and in an environment where anthropogenic pressure manifests. The presented studies represent a range of research using analytical methods to determine the presence of heavy and toxic metals in different segments of bees and their products, linking these findings with the state of the environment. It has been repeatedly established that if heavy and toxic metals are present in higher concentrations in components of the environment that are under anthropogenic pressure, then their concentrations in bees, honey, and wax will also be higher. By summarizing this research in one place, this study can provide guidelines for future scientific work on this subject, promoting sustainable development through safe beekeeping and healthy bees.

The Diagnostic Value of qPCR Quantification of Paenibacillus larvae in Hive Debris and Adult Bees for Predicting the Onset of American Foulbrood.

American foulbrood (AFB) is a serious infectious disease of honeybees (Apis mellifera) caused by Paenibacillus larvae. Increased P. larvae count in hive-related material is associated with an increased risk of AFB. Here, we quantified P. larvae cells in 106 adult bee and 97 hive debris samples using quantitative PCR (qPCR); 66/106 adult bee and 66/97 hive debris samples were collected simultaneously from the same bee colony (paired-sample design). The corresponding bee colonies were also examined for the presence of AFB clinical signs. A binary logistic regression model to distinguish between AFB-affected and unaffected honeybee colonies showed a strong diagnostic accuracy of both sample types for predicting the onset of AFB based on P. larvae counts determined by qPCR. The colonies with a P. larvae count greater than 4.5 log cells/adult bee or 7.3 log cells/mL hive debris had a 50% probability of being clinically affected and were categorized as high-risk. The AFB-unaffected colonies had significantly lower P. larvae counts than the AFB-affected colonies, but the latter did not differ significantly in P. larvae counts in relation to the severity of clinical signs. Both bee-related sample types had a high diagnostic value for predicting disease outcome based on P. larvae counts. These results improve the understanding of the relationship between P. larvae counts and AFB occurrence, which is essential for early detection of high-risk colonies.

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

Barriers to Successful Beekeeping: Insights from the Jammu Region of Jammu and Kashmir, India

This study focused on the constraints faced by the beekeepers of Jammu region of Jammu and Kashmir, evaluating constraints perceived by the beekeepers identified from Krishi Vigyan Kendras (KVKs) who have been involved in beekeeping for the last five years at least and the list contained eight beekeepers. By using the sampling method with replacement, the sample size of eight beekeepers were interviewed two times and comparison made for three time periods or years viz; 2019-20, 2021-22 and 2023-24, which made the ultimate sample size of twenty four (24) beekeepers. For analyzing the data collected for three time periods, Henry Garrett’s ranking and Chi-square test were used. Findings indicated that major production constraints were the disease of honey bees (78.60), death of the colony (70.00), and heavy rainfall (61.00). Marketing constraints included the fluctuating price of raw honey (69.20), unorganized and unregulated markets (63.20) and lack of government concern or support for the marketing of honey (55.80). Economic constraints featured the huge cost of investment is ranked first with an average score of 71.00, followed by no insurance facilities for the beehives with an average score of 53.67 and lack of credit supply for costly implements used in processing, packaging and quality testing (50.67). Chi-square test revealed that only two constraints under production problems such as, the lack of beehive equipments and materials in the local market (14.77) and pesticide poisoning (7.88) were significant and were showing dependency over the years. By addressing all these constraints through targeted interventions could significantly enhance the viability of beekeeping.

Beekeeping breakthrough: unveiling hive health with a portable membrane inlet mass spectrometry detection method

Supporting bee populations is essential considering threats posed by human activities like pesticide usage and habitat destruction. However, the current methods for monitoring and analyzing beehives and their surrounding environments are invasive, complex, and time-consuming. These methods often rely heavily on laboratory analyses, making them difficult to implement independently in the field. This study explores the application of portable membrane inlet mass spectrometer (MIMS) for noninvasive hive analysis, demonstrating its ability to detect various compounds indicative of hive conditions and environmental stressors. In addition to the expected compounds found in beehives, such as α-bergamotene, hexadecanoic acid, heptadecane, hexadecanamide, α-bisabolol-, 9-octadecenamide, (Z) − , and benzaldehyde, unexpected compounds, pollutants, like indane (polycyclic aromatic hydrocarbon) and carbofuran (pesticide), were also detected. The MIMS detection method provides rapid, accurate, and real-time results, making it suitable for preventive measures against bee diseases and integral to environmental biomonitoring. This integration of technology represents a significant advancement in bee conservation efforts, offering hope for the future of both bees and ecosystems.

Diagnostic study on major honeybee disease, pests and predators in North Western Ethiopia.

The study was conducted in Pawe district from Benishangul-Gumuz and Jawi and Fagita Lekoma districts from the Amhara region to investigate major honeybee pests, predators and diseases. Using a purposive sampling technique, 183 households were interviewed, and 240 samples were collected for laboratory analysis of bee disease; data were analysed using descriptive statistics. The share of hive types owned by sampled respondents was 88.6%; overall, 1.1% and 10.3% were traditional, transitional and modern beehives, respectively. About 92% of the sample respondents acquired their base colonies by catching swarm bees on the apex of trees. The majority of beekeepers executed external inspections of their colony, whereas only 50% carried out internal inspections. Based on the responses of beekeepers, around 48.9%, 56.3% and 23.1% of colonies absconded every year from Pawe, Jawi and Fagita Lekoma districts, respectively. Ants, wax moths, bee lice, beetles, spiders, birds, monkeys and honey badgers were the major honeybee pests and predators discovered in study areas in decreasing order. Concerning the incidence of Varroa mites, Nosema apis and amoeba disease, 27.5%, 60% and 71.6% of samples showed positive results in study locations, respectively. From this result, we observed that ants, wax moths, bee lice, beetles, spiders, birds, monkeys and honey badgers were the major honeybee pests and predators. The prevalence of amoeba disease was comparatively higher in highland areas and in the summer season. This finding suggests the need for the alertness of beekeepers in controlling bee disease and pests and strengthening bee colonies through seasonal colony management. There should be a strict quarantine, and check-up undertaken when a new colony is purchased from one region to another is essential.

Tetracycline-induced gut community dysbiosis and Israeli Acute Paralysis Virus infection synergistically negatively affect honeybees

Antibiotics are frequently employed to control bacterial diseases in honeybees, but their broad-spectrum action can disrupt the delicate balance of the gut microbiome, leading to dysbiosis. This imbalance in the gut microbiota of honeybees adversely affects their physiological health and weakens their resistance to pathogens, including viruses that significantly threaten honeybee health. In this study, we investigated whether tetracycline-induced gut microbiome dysbiosis promotes the replication of Israeli acute paralysis virus (IAPV), a key virus associated with colony losses and whether IAPV infection exacerbates gut microbiome dysbiosis. Our results demonstrated that tetracycline-induced gut microbiome dysbiosis increases the susceptibility of honeybees to IAPV infection. The viral titer in worker bees with antibiotic-induced gut microbiome dysbiosis prior to IAPV inoculation was significantly higher than in those merely inoculated with IAPV. Furthermore, we observed a synergistic effect between tetracycline and IAPV on the disruption of the honeybee gut microbiome balance. The progression of IAPV replication could, in turn, exacerbate antibiotic-induced gut microbiome dysbiosis in honeybees. Our research provides novel insights into the role of the gut microbiota in host-virus interactions, emphasizing the complex interplay between antibiotic use, gut microbiome health, and viral susceptibility in honeybees. We highlight the crucial role of a balanced gut microbiota in honey bees for their immune response against pathogens and emphasize the importance of careful, safe antibiotic use in beekeeping to protect these beneficial microbes.

Antibiotics, pesticides, and heavy metals contaminants of honey as affected by antibiotics usage and agricultural practices in different Egyptian environments

Background and aim Environmental pollutants and global climate changes have a negative health effect on honeybees, and increase honey contamination.The aim of this study was to test the effect of antibiotic usage and agricultural practices on the presence of a total of 461 pesticides, 30 antibiotics, and five elements traces in honey samples collected from Egyptian apiaries of different environmental conditions representing intensive, and limited agriculture production regions. Materials and methods Pesticides and antibiotic residues in honey were detected at trace levels using tandem mass spectrometry techniques Gas Chromatography-Mass Spectrometry/Mass Spectrometry and Liquid Chromatography-Mass Spectrometry/Mass Spectrometry (GC-MS/MS and LC-MS/MS). Antibiotics were detected using only Liquid Chromatography-Mass Spectrometry/Mass Spectrometry LC-MS/MS. The quadrupole inductively coupled plasma mass spectrometry technique (QICP-MS) was applied for the trace element analysis. Results and conclusion Amitraz and acetamiprid were more frequent. The highest concentration of amitraz (0.022 mg/kg) was found in samples obtained from apiaries in the north delta. Iron and zinc were the highest frequently detected elements in all the collected honey samples. Also, Cu was less frequently detected elements in honey samples with percent values of 7%. Cd and Pb were found in honey samples from apiaries in the south delta of Egypt at 20%, and 27%, respectively. Most of the collected samples were contaminated with antibiotics. A direct relation between agriculture production and uncontrolled antibiotics applications on a beehive was concluded due to the increased diseases of bees in the regions of intensive agriculture production. Only two pesticides were detected along with low concentrations of toxic elements in too low levels to exceed their ‘European Union Maximum Residue Limit’ EU MRL.

What proteomics has taught us about honey bee (Apis mellifera) health and disease.

The Western honey bee, Apis mellifera, is currently navigating a gauntlet of environmental pressures, including the persistent threat of parasites, pathogens, and climate change - all of which compromise the vitality of honey bee colonies. The repercussions of their declining health extend beyond the immediate concerns of apiarists, potentially imposing economic burdens on society through diminished agricultural productivity. Hence, there is an imperative to devise innovative monitoring techniques for assessing the health of honey bee populations. Proteomics, recognized for its proficiency in biomarker identification and protein-protein interactions, is poised to play a pivotal role in this regard. It offers a promising avenue for monitoring and enhancing the resilience of honey bee colonies, thereby contributing to the stability of global food supplies. This review delves into the recent proteomic studies of A. mellifera, highlighting specific proteins of interest and envisioning the potential of proteomics to improve sustainable beekeeping practices amidst the challenges of a changing planet.

Winter Hive Debris Analysis Is Significant for Assessing the Health Status of Honeybee Colonies (Apis mellifera).

Honeybee diseases are one of the most significant and most common causes of honeybee colonies' weakness and death. An early diagnosis of subclinical infections is necessary to implement precautionary and control measures. Sampling debris from hive bottom boards is simple, non-invasive, and cheap. In this study, we collected winter debris samples in apiaries located in the continental part of Croatia. We used molecular methods, PCR and qPCR, for the first time to analyze those samples. Laboratory results were compared with the health condition and strength of honeybee colonies at an apiary in spring. Our study successfully identified the presence and quantity of various pathogens, including the presence of Vairimorpha spp. (Nosema spp.), quintefied Paenibacillus larvae, Acute Bee Paralysis Virus (ABPV), Black Queen Cell Virus (BQCV), Deformed Wing Virus (DWV), and Sacbrood Virus (SBV). However, our analysis did not detect Melissococcus plutonius, Crithidia mellificae, Lotmaria passim, and Aethina tumida. Samples of winter debris were also examined for the presence and quantification of the V. destructor mites, and their natural mite fall was observed in spring. Honeybee colonies were simultaneously infected by an average of four to six pathogens. Some observed honeybee colonies developed characteristic symptoms, while others did not survive the winter.

Preliminary Study on the Pathogenic Mechanism of Jujube Flower Disease in Honeybees (Apis mellifera ligustica) Based on Midgut Transcriptomics.

Honeybees are prone to poisoning, also known as jujube flower disease, after collecting nectar from jujube flowers, resulting in the tumultuous demise of foragers. The prevalence of jujube flower disease has become one of the main factors affecting the development of the jujube and beekeeping industries in Northern China. However, the pathogenic mechanisms underlying jujube flower disease in honeybees are poorly understood. Herein, we first conducted morphological observations of the midgut using HE-staining and found that jujube flower disease-affected honeybees displayed midgut damage with peritrophic membrane detachment. Jujube flower disease was found to increase the activity of chitinase and carboxylesterase (CarE) and decrease the activity of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and the content of CYP450 in the honeybee midgut. Transcriptomic data identified 119 differentially expressed genes in the midgut of diseased and healthy honeybees, including CYP6a13, CYP6a17, CYP304a1, CYP6a14, AADC, and AGXT2, which are associated with oxidoreductase activity and vitamin binding. In summary, collecting jujube flower nectar could reduce antioxidant and detoxification capacities of the honeybee midgut and, in more severe cases, damage the intestinal structure, suggesting that intestinal damage might be the main cause of honeybee death due to jujube nectar. This study provides new insights into the pathogenesis of jujube flower disease in honeybees.

Micronutrient Deficiency May Be Associated with the Onset of Chalkbrood Disease in Honey Bees.

Chalkbrood is a disease of honey bee brood caused by the fungal parasite Ascosphaera apis. Many factors such as genetics, temperature, humidity and nutrition influence the appearance of clinical symptoms. Poor nutrition impairs the immune system, which favors the manifestation of symptoms of many honey bee diseases. However, a direct link between dietary ingredients and the symptoms of chalkbrood disease has not yet been established. We show here that the elemental composition of chalkbrood mummies and healthy larvae from the same infected hives differ, as well as that mummies differ from larvae from healthy hives. Chalkbrood mummies had the highest concentration of macroelements such as Na, Mg, P, S, K and Ca and some microelements such as Rb and Sn, and at the same time the lowest concentration of B, As, Sr, Ag, Cd, Sb, Ba and Pb. Larvae from infected hives contained less Pb, Ba, Cs, Sb, Cd, Sr, As, Zn, Cu, Ni, Co, Mn, Cr, V and Al in contrast to healthy larvae from a disease-free apiary. This is the first study to demonstrate such differences, suggesting that an infection alters the larval nutrition or that nutrition is a predisposition for the outbreak of a chalkbrood infection. Though, based on results obtained from a case study, rather than from a controlled experiment, our findings stress the differences in elements of healthy versus diseased honey bee larvae.

Identification and pathogen detection of a Neocypholaelaps species (Acari: Mesostigmata: Ameroseiidae) from beehives in the Republic of Korea.

In this study, we identified a new strain of the genus Neocypholaelaps from the beehives of Apis mellifera colonies in the Republic of Korea (ROK). The Neocypholaelap sp. KOR23 mites were collected from the hives of honeybee apiaries in Wonju, Gangwon-do, in May 2023. Morphological and molecular analyses based on 18S and 28S rRNA gene regions conclusively identified that these mites belong to the genus Neocypholaelaps, closely resembling Neocypholaelaps sp. APGD-2010 that was first isolated from the United States. The presence of 9 of 25 honeybee pathogens in these mite samples suggests that Neocypholaelaps sp. KOR23 mite may act as an intermediate vector and carrier of honeybee diseases. The identification of various honeybee pathogens within this mite highlights their significance in disease transmission among honeybee colonies. This comprehensive study provides valuable insights into the taxonomy and implications of these mites for bee health management and pathogen dissemination.

Diagnostic Survey of Honeybee Diseases, Pests and Predators in Selected Districts of West Hararghe Zone of Oromia, Ethiopia

The study was conducted in Darolabu, Ciro and Gemechis Districts of West Hararghe Zone with the objective of determining the occurrence and prevalence of honeybee diseases, pests and predators and their effects on honeybee colonies and bee products in selected districts of West Hararghe Zone. Three districts were purposefully selected based on their relative beekeeping potentials in highland, midland and lowland agro–ecologies. Three Kebeles from each district and ten beekeepers from each Kebeles were selected for the interview. For major honey bee diseases and pest examination, a total of 68 suspected bee colonies were sampled. Out of the total respondents, 58% and 77.4% of beekeepers replied that honeybee colonies and honey yield, respectively, were decreasing from time to time. The respondents listed a lack of bee forages, disease, pest and predators as the major constraints of beekeeping in the study area in their decreasing orders. Wax moth, honey badger and hive beetles were more commonly occurring pests and predators, while nosema and amoeba were among the important diseases. The prevalence all bee diseases and pests including nosema, amoeba, varroa mite, bee lice, wax moth, and small hive beetle, was not associated with either agro-ecology or hive type. The factors contributing for their prevalence across all agro-ecologies and hive types need further study.

Bee Diseases, Treatments, and Prevention in the Folklore of the Ordu-Giresun Region in Türkiye

The Eastern Black Sea Region, which has a very important position in honeybee breeding, stands out with its valuable nectar and pollen resources for bees, thanks to its rich plant species. In this region, beekeeping is carried out intensively and traditional knowledge is also used. This research aimed to reveal the folkloric data related to bee diseases, their treatments, and prevention from the disease in Ordu-Giresun Region, evaluate the obtained data with rational data, and contribute to veterinary medicine folklore, in particular beekeeping. The study material consisted of the data obtained from 39 volunteers, who were determined to have good knowledge about beekeeping in Ordu-Giresun Region, between 26 August 2017 and 20 September 2018. The data obtained from the participants were specified in the results section as a superscript at the end of each data. The information compiled using the information compilation form was analyzed under “bee diseases, treatments and prevention” and “hive disinfection and bee immunity”. The study determined that the data obtained on six different bee diseases and food poisoning in bees were generally compatible with the literature on the subject. As a result, it can be stated that the folkloric medicine based on experience regarding bee diseases, treatments, and protection from diseases continues to be practiced today in Ordu-Giresun Region, but the source persons could not provide or have no knowledge about viral diseases of bees and poisoning caused by pesticides; however, folkloric methods applied in beekeeping are sensible and rational in the light of scientific data. Keywords: Bee, Folklore, Ordu-Giresun Region, Türkiye.

Investigation of resistance against to flumethrin using against Varroa destructor in Türkiye

The honeybee ectoparasite Varroa destructor is a major threat to apiculture when evaluating bee diseases and pests. While attempting to control this mite, beekeepers often depend on a small selection of authorized synthetic acaricides, such as flumethrin, which is widely used in Türkiye and globally. However, resistance to flumethrin develops due to incorrect and excessive use. In this study conducted at Ordu Beekeeping Research Institute, trial group were established including an untreated control group and group where flumethrin-based pesticides were applied. Dead varroas collected from pollen traps and live varroas collected from bees were obtained from these trial groups for molecular analysis as positive-negative controls. Varroa samples were collected from provinces representing different regions with intensive beekeeping activities such as Adana, Ankara, Bingöl, Muğla, Ordu, Şanlıurfa, Tekirdağ. Molecular methods were employed to investigate the resistance gene region for pyrethroids (specifically flumethrin) against V. destructor. In our study, individual DNA extractions were performed on dead parasites from colonies subjected to pyrethroid application (resistance negative control) and live parasites (resistance positive control). The DNA samples obtained were used in PCR reactions targeting the region encoding the 925th amino acid of the voltage-gated sodium channel (VGSC) gene, which is responsible for resistance formation. The DNA samples were subjected to gel electrophoresis to observe the amplification products of the expected target region. To examine the nucleotide sequence changes that encode leucine at the 925th amino acid, which is associated with resistance, DNA sequence analysis was applied to the amplification products. Out of 332 V. destructor parasites obtained from different provinces, 279 were analysed using molecular methods. It was observed that 31% of the samples showed sensitivity to flumethrin while 69% exhibited resistance to it. Among the resistant samples: 27% had homozygous isoleucine mutation; 28% had homozygous valine mutation; 2.8% had heterozygous isoleucine mutation; 8.5% had heterozygous valine mutation; and 2.8% had heterozygous methionine mutation, all of which were associated with flumethrin resistance. As a result, the rate of flumethrin resistance in parasites varied between 51% and 94% among different provinces.