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Varroa mite population per sample of bees at different dates of observation after application of oxalic acid @ 7.2 mL per honey bee (Apis mellifera) colony by shop towel method. All the data are represented as mean ± standard error (indicated as error bars). Bars with different letters indicate significant (p ≤ 0.05) difference among the observation dates. ETL = Economic Threshold level; DAT = Days after treatment.
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The parasitic mite Varroa destructor is amongst the most serious problems of honey bees, Apis mellifera (Hymenoptera: Apidae) around the world including Pakistan. The present study estimates the mite density through powdered sugar roll method and evaluates the effectiveness of five miticides (fluvalinate, flumethrin, amitraz, formic acid, and oxali...
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Context 1
... 142.36; p ≤ 0.001) between dates of observation and the means comparison of the data revealed pre-treatment data differed significantly in the mite population from that of 4th to 15th days after treatment, whereas there were non-significant differences between mite population of 18th and 22nd days after treatment. The mite population exceeded the (Fig. 7). This experiment reflected the effectiveness of oxalic acid through a shop towel method to control the mite population up to two weeks during the 2nd fortnight of December 2017 (low population density of ...
Context 2
... Varroa mites. Experiment 7 was conducted to evaluate the effectiveness of oxalic acid for phoretic Varroa during the period of low queen egg laying (2nd fortnight of December). Oxalic acid applied through shop towel method against Varroa mites during winter and was found effective to keep mites below ETL (6 mites per 300 bees) up to 14 days (Fig. 7). The bees eagerly assumed the paper towel containing oxalic acid. This method may be a promising alternate of sublimation and sugar syrup drip application of oxalic acid. The oxalic acid application was not repeated keeping in view that prolonged exposure of this acid may pose harmful effects to adult bees. Results of this study were ...
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Over the past few decades, the ectoparasitic mite Varroa destructor has been a significant threat to managed honey bee (Apis mellifera) colonies worldwide. Many control methods, including application of synthetic acaricides, have been adopted to control the infestation of varroa mites in honey bee colonies. Synthetic acaricides such as coumaphos an...
Citations
... Through a rigorous screening process, we narrowed our focus to 50 colonies. This selection was based on several critical criteria: the size of the honey bee population was comparable across the chosen colonies, they were queen right, and they exhibited a mite infestation level exceeding the economic threshold of 3 to >10 adult mites per 100 bees [61]. Moreover, the colonies designated for the experiments were in a mature stage of development and demonstrated high productivity levels. ...
... The final step involved the calculation of the mite infestation rate, which was achieved by dividing the total number of mites by the total number of bees sampled. The research established a standard economic threshold for action at a 2% mite presence per 100 bees, translating to a critical limit of 6 Varroa mites per 300 adult bees during periods of low population (dearth periods) and a heightened threshold of 9 Varroa mites per 300 bees during peak population seasons, typically observed from February to March [61]. The acaricidal potential of the oils was quantified using the following formula for percentage reduction. ...
Honey bees are crucial for ecosystem pollination and honey production, yet the Varroa destructor mite hinders their productivity and health. Efforts to manage Varroa mites with synthetic pesticides have had limited success, highlighting the need for naturally derived acaricides as a primary option. However, the acaricidal efficacy of essential oils from Salvia officinalis L. (sage), Cannabis sativa (hemp), and Laurus nobilis (laurel) remains to be fully understood. This study aims to investigate the acaricidal efficacy of these three essential oils at varying concentrations and their impact on honey production, focusing on the efficient reduction in Varroa mites. The sugar roll method was employed to assess Varroa mite infestation levels, while GC-MS analysis was utilized to verify the composition of the essential oils. Honey production measurements were also performed. The efficacy rates (%) at concentrations of 15%, 10%, and 5% for hemp oil were 95.4% ± 0.30%, 85.71% ± 0.85%, and 64.48% ± 0.26%, respectively; for sage oil, they were 81.08% ± 0.57%, 69.42% ± 1.72%, and 50.35% ± 0.70%; and for laurel oil, they were 68.96% ± 0.34%, 54.66% ± 0.37%, and 33.58% ± 0.30%, respectively. Key compounds identified include trans-caryophyllene, α-pinene, and viridiflorol in hemp oil; myrcene, limonene, and β-caryophyllene in sage oil; and phytol, β-myrcene, and n-heneicosane in laurel oil. The overall findings indicate that hemp oil is highly effective in controlling Varroa mites. However, further research is needed to evaluate its potential side effects on bees to ensure its sustainability and safety.
... (Bjerge et al., 2019) proposed an Infestation Level Estimator (ILE) to determine the level of infestation by the mite Varroa destructor. Despite obtaining a relatively high F1-score=0.91 for the detection of varroa mites and confirming the ability to recognise the presence of this mite on bees, the following problems of the proposed solution can be noted: (1) the significant modification of the hive to install the machine vision system, which may affect the daily functioning of the bees, (2) performing the dataset development and validation process for bee populations with relatively high infestation levels (5-10%), assuming an infestation level of 2% as an acceptable (Sajid et al., 2020). An effective pest detection solution should: (1) be designed to operate under the real conditions of farming with as little interference with insect functioning as possible, (2) be developed and evaluated for samples associated with different degrees of pest infestation in the population -the most difficult is to detect pests at low levels of infestation with an adequate level of precision (this is the situation most often found under professional farming conditions.). ...
Pest detection is an important application problem as it enables early reaction by the farmer in situations of unacceptable pest infestation. Developing an effective pest detection model is challenging due to the problem of creating a representative dataset, as episodes of pest occurrence under real rearing conditions are rare. Detecting the pest Alphitobius diaperinus Panzer in mealworm (Tenebrio molitor) rearing, addressed in this work, is particularly difficult due to the relatively small size of detection objects, the high similarity between detection objects and background elements, and the dense scenes. Considering the problems described, an original method for developing pest detection models was proposed. The first step was to develop a basic model by training it on a small subset of manually labelled samples. In the next step, the basic model identified low/moderate pest-infected rearing boxes from many boxes inspected daily. Pseudo-labelling was carried out for these boxes, significantly reducing labelling time, and re-training was performed. A spatio-temporal masking method based on activity maps calculated using the Gunnar-Farneback optical flow technique was also proposed to reduce the numerous false-positive errors. The quantitative results confirmed the positive effect of pseudo-labelling and spatio-temporal masking on the accuracy of pest detection and the ability to recognise episodes of unacceptable pest infestation.
... However, it has been able to successfully exploit A. mellifera as a new host where it is believed to have caused up to 50% of colony losses in India, and decimated colonies in Afghanistan, causing an estimated 95% of colony losses in just three years. Therefore, it is a serious pest and beekeepers need to control mite numbers by using acaricides or creating brood fewer periods (Jamal et al., 2020;Sajid et al., 2020). To add to their problems Varroa destructor was reported in 2002 and typically was already widely spread throughout their A. mellifera colonies. ...
Authors' Contribution KAK did conceptualization, investigation , projct administration and supervision, and wrote origincal draft. HAG and KAK arranged resources, and reviewed and edited the manuscript. HAG acquired funds.
... Pour les acaricides utilisés en apiculture biologique, l'efficacité doit être supérieure à 90% (Wendling, 2014). Ces résultats ne sont malheureusement pas toujours obtenus (Gregorc et al., 2018;Loucif-ayad et al., 2010;Norain Sajid et al., 2019). L'efficacité du traitement est pourtant primordiale pour maintenir un taux d'infestation inférieur au seuil recommandé (voir § Evaluation du taux d'infestation) (Dooremalen et al., 2012). ...
Varroa destructor is a honeybee ectoparasite that leads to colony collapse within few years if the infestation is too high. Beekeepers have several acaricide substances authorized in France to control the infestation. Tau-fluvalinate was widely used in the 90s until varroa developed resistances significantly reducing the effectiveness of treatments. The second most used acaricide substance is amitraz. Annual treatment was sufficient to maintain low infestation. But in recent years, observations of decreased efficacy have been observed by beekeepers and the application of a second winter treatment is becoming common. Several parameters can influence the efficacy of treatments. We will focus on the study of Varroa resistance to tau-fluvalinate and amitraz.
First, we tried to detect the presence of varroas resistant to acaricides in France. A phenotypic sensitivity test was used to detect the presence of resistant mites in a population. Using sensitive reference populations, we selected the discriminant concentration method (LC90) to determine the proportion of resistant mites in a population. We established three sensitivity classes according to the results obtained: sensitive (Mortality>76%), moderate resistance (Mortality 75-41%) and high resistance (Mortality <<40%). In France, out of 59 samples collected, 45% and 66% of populations are moderately or highly resistant to tau-fluvalinate and amitraz, respectively.
Then, using a model, we analyzed the impact of various parameters, including the presence of resistant varroa on the efficacy of Apivar treatment. A moderately resistant population will result in a loss of efficacy of 5-10% while a highly resistant population will result in an efficacy of less than 78%. Highly resistant populations observed in the field confirmed these simulated model results. We also found that initial infestation, treatment period and treatment formulation influenced the efficacy of treatment.
The management of varroa by beekeepers must now include resistance management. For this, control strategies proposed by the Insect Resistance Management (IRM) could limit the spread of resistant mites. Pharmaceutical laboratories may also contribute to the reduction of resistance by developing treatments that reduce their duration and optimize the dose of acaricide. In this context, we propose to develop a Varroa Resistance Management (VRM) that corresponds to the different actions to be carried out to control resistance in the current state. IN addition to VRM, the beekeeper must also maintain a low infestation in its colonies to ensure sufficient treatment efficacy. The development of resistance to mites complicates the management of honeybee colony infestation, requiring beekeepers to adapt and develop new control strategies.
... Similar mite counts were observed after two thymol treatments (Apiguard and Thymovar). Sammataro et al. [27], Mathieu and Faucon [40], and Sajid et al. [41] assessed the efficacy of fluvalinate, flumethrin, amitraz, formic acid, and oxalic acid in reducing mite infestation levels in adult honey bees. ...
The requirement for the protection of bee colonies against Varroa destructor invasions has been noted by many breeders and is included as an aspect of the development of beekeeping. This research aimed to check the effect of the development of a colony exposed to laying eggs (brood surface) by queen bees with similar chemical potential (sisters) on the effect of a preparation combating V. destructor depending on the number of mites found in a given colony. We chose this as a standard model of conduct that treats each bee colony as one organism subjected to individual parasite control. For this purpose, we created a bee colony with a mother-of-one breeding line and fertilised drones from one colony. Infection with V. destructor occurred naturally and uncontrollably. Without interfering with the colony’s development, the frame insulator helped each colony’s brood (mothers’ reproductive potential) and the initial and final individuals from the mites themselves. The study was carried out in four species (two control species and two species with up to 20 and over 21 mites, respectively). Treatments with amitraz to combat damage were divided into four treatment subgroups: two treatments every four days or four treatments every two days. We observed the number of individuals that were protected in all subgroups in the average brood area. The reproductive potential of the sisters’ mothers did not change after the treatments with amitraz, which indicated that amitraz did not affect the delegation of egg laying. The invasion rate was also tracked relative to the control group, which allowed us to conclude that a two-time treatment with amitraz reduced the frequency of mites and a four-time treatment checked the effectiveness. Tailoring the control of V. destructor in bee colonies may be an effective measure in the fight against this parasite.
... (ZHU; YAO;WANG, 2022) Os primeiros relatos do aparecimento do Varroa destructor se deu em 1949, com o nome de Varroa jacobsoni, a abelha oriental Apis cerana foi seu hospedeiro original e somente a partir do momento que o Varroa destructor migrou para abelhas ocidentais que o ácaro tornou-se um dos patógenos apícolas mais prejudiciais em todo o mundo, capaz de matar colônias inteiras, principalmente durante o inverno, por estes motivos o ácaro Varroa é considerado o principal fator para o declínio global das abelhas, enquanto os danos causados na Apis cerana são mínimos. (NORAIN SAJID et al., 2020) Com o passar dos anos, espécies de abelhas e ácaros passaram por processos evolutivos que proporcionaram vantagens biológicas para sobrevivência. A redução do período de póscapeamento, aumento do comportamento higiênico e comportamento de limpeza foram as principais características estudadas na literatura recente. ...
... (MIRANDA, 2016) No Brasil, os primeiro ácaros Varroa em abelhas foram detectados somente em 1978. (NORAIN SAJID et al., 2020). ...
... Este composto é considerado um piretróide e age através dos canais de sódio controlados por sinais elétricos e estimulam descargas elétricas repetitivas ou uma despolarização prolongada da membrana, causando espasmo muscular, distúrbio de movimento e também morte dos ácaros. (NORAIN SAJID et al., 2020) Em pesquisas realizada por Sabová et al. (2022), foi demonstrado que o contato com fluvalinato reduz consideravelmente a capacidade de retorno de abelhas durante o forrageamento quando se há o distanciamento de 2km da colônia, principalmente quando os resíduos nas abelhas ultrapassaram 5mg/kg. Já quando os resíduos das abelhas foram superior a 50 mg/kg, o tempo de retorno para a colônia, o tempo de forrageamento e a taxa de retorno foram severamente afetados. ...
Com o passar dos anos, o franco desenvolvimento e evolução do sistema alimentar tem garantido o acesso à alimentação básica em todo o planeta e a apicultura tem exercido papel-chave neste processo. Por conta da polinização de plantações agrícolas e também do fornecimento de produtos derivados do mel, as abelhas têm sido cada vez mais estudadas na área de sistemas agroindustriais para que se garanta a sobrevivência e produtividade de suas colônias. Atualmente um dos principais desafios para garantir a saúde das colônias é o enfrentamento do ectoparasita Varroa destructor. Este ácaro tem sido o principal vilão para as abelhas melíferas ocidentais por conta de suas características parasitárias, seu ciclo de reprodução e principalmente por ser vetor de transmissão de diversas doenças. Os apicultores utilizam diversas técnicas e práticas para redução ou erradicação de ácaros, como métodos apícolas biotécnicas, acaricidas sintéticos e acaricidas orgânicos ou suaves, e novos desafios surgem de acordo com a abordagem escolhida para o tratamento. São frequentes os relatos de contaminação do mel, exposição das abelhas a acaricidas em doses subletais, evolução genética dos ácaros a determinados acaricidas, entre outras adversidades. A continuidade de estudos de campo e laboratoriais são determinantes para que as práticas dos apicultores quanto ao enfrentamento ao Varroa seja efetivo e não produza efeitos colaterais a longo ou a curto prazo.
... As such, it is highly effective in the control of various ticks, lice, mites and other parasites (Stanneck et al., 2012). A common method of Varroa mite used around the world is to hang plastic strips of flumethrin between frames to spread flumethrin to each other through the activity of bees, thus exerting a Varroa mite killing effect (Sajid et al., 2020). However, flumethrin residues have been increasingly detected in bee products and hives due to the unregulated practice of beekeepers (overdose addition based on resistance of V. destructor) and the chronic slow-release effect of the chemical. ...
Flumethrin is a highly effective acaricide, but its lipophilic characteristic has some negative effects, such as accumulation in bee hives and bee products. However, studies on the survival stress of honey bees subsequent to chronic flumethrin exposure are limited. To answer this question, a study was carried out on the stress to honey bee (Apis mellifera) workers from larvae to adults by chronic exposure to sublethal concentrations of flumethrin. Three flumethrin treatment groups (1, 0.1, 0.01 mg/L) and one control group (with no added flumethrin) were established and divided the worker larvae into four groups. Then, starting with 2-day-old larvae, larvae and subsequent emerged worker bees of the four groups were orally fed with the corresponding concentrations of flumethrin until all the adult worker bees died, respectively. When the concentration was at 0.01 mg/L of flumethrin, the lifespan of adult worker bees decreased, and a down-regulation of detoxification-related genes (CYP450,GSTS) was induced in 1-day-old pupae. When it is at 0.1 mg/L flumethrin, the lifespan of adult worker bees was again shortened, and down-regulation of memory-related genes (GluRA1, Nmdar1, Tyr1) in 1-day-old pupae and gene Tyr1 in 1-day-old worker bees, detoxification-related genes (CYP450,GSTS) in 1-day-old pupae, and immunity genes (Defensin1, Hymenoptaecin) in 7-day-old worker bees were observed. When the concentration is at 1 mg/L flumethrin, lighter birth weight of newly emerged honeybee was found and deficiencies in olfactory learning and memory were observed in 7-day-old worker bees. Memory-related genes (GluRA1, Nmdar1, Tyr1) were down-regulated in 1-day-old pupae and genes (Nmdar1,Tyr1)in 1-day-old worker bees, as were detoxification-related genes (CYP450,GSTS) in 1-day-old pupae and gene CPY450 in 7-day-old worker bees, and immune genes (Defensin1, Hymenoptaecin) in 7-day-old worker bees. There was no significant difference in pupal weight, capping rate, emergence rate, expression of immune-related genes of 1-day-old pupae, expression of immune-related genes and detoxification-related genes of 1-day-old worker bees, expression of memory-related genes and detoxification-related gene GSTS of 7-day-old worker bees. These data provide an ominous warning about the unintended consequences on apiaries, and underscore the need for careful control of flumethrin residues in bee hives.
... Mite colony infection causes the bees to lose weight, deform, or lose limbs, and sometimes make young bees die. Varroa mite is one of the most important and destructive pests of beehives that causes irreparable damage to the beekeeping industry [11,16]. Varroa destructor is also the main pest of honey bees, as the bee population in Varroa-infested colonies is deteriorating significantly [8]. ...
... Surviving colonies were initially treated for 48 h with HopGuard (DeGrandi-Hoffman et al. 2012), with dead mites collected on sticky cards. To maximize the likelihood of collecting the greatest percentage of the remaining mites, the colonies were then treated with a 4% oxalic acid sugar syrup solution (Norain Sajid et al. 2020), with mites collected on sticky cards for 48 h after treatment. For purposes of this experiment, we considered that the combination of the two miticide treatments over 4 d removed all remaining mites in the dispersal phase. ...
Indoor storage of honey bees (Apis mellifera L.) during winter months has been practiced for decades to protect colonies from the adverse effects of long, harsh winter months. Beekeepers have recently employed indoor storage to reduce labor, feeding costs, theft, and woodenware degradation. Despite the growing number of colonies stored indoors, national survey results still reveal high losses. Varroa mites (Varroa destructor Anderson and Trueman) are the most critical threat to colony winter survival and health of colonies because they contribute to the transmission of viruses and colony mortality. To investigate the effect of high CO2 on varroa mites during the indoor storage of honey bees, 8-frame single deep colonies were stored in two separate environmental chambers at 4°C each. One environmental chamber was set at 8.5% CO2 (high CO2), while the other was set at low CO2 (0.12%). Dead and falling mites were collected and counted from the bottom of individual colonies weekly during the experiment. There was a significant difference in mite mortality of colonies with high CO2 compared to colonies held at low CO2. These results indicated that high CO2 could increase mite mortality during the period of indoor storage, potentially improving honey bee health coming out of the winter months. Our research offers a critical addition to beekeepers' tools for managing varroa mite populations.
... Pour les acaricides utilisés en apiculture biologique, l'efficacité doit être supérieure à 90% (Wendling, 2014). Ces résultats ne sont malheureusement pas toujours obtenus (Gregorc et al., 2018;Loucif-ayad et al., 2010;Norain Sajid et al., 2019). L'efficacité du traitement est pourtant primordiale pour maintenir un taux d'infestation inférieur au seuil recommandé (voir § Evaluation du taux d'infestation) (Dooremalen et al., 2012). ...
BACKGROUND
Varroa destructor is a parasite of honeybees. It causes biological damage leading to the colony collapse in the absence of treatment. In recent years, acaricide resistance has emerged in Varroa mites, leading to a decrease in treatment efficacy. We modelled the action of Apivar (amitraz) treatment, using three input parameters: treatment duration, treatment period, and daily mortality due to the treatment. The output parameters were cumulative mite mortality during treatment, the residual number of Varroa mites, and treatment efficacy, expressed as a percentage.
RESULTS
The model was validated by monitoring efficacy in the field, in 36 treated hives. According to the model, treatment in the absence of brood is optimal. For a long period without egg laying during the winter, an initial infestation of 100 mites and a start date for treatment of August 7, a minimal treatment efficacy of 98.8% is required for stabilization of the mite population for year to year. More effective treatment is associated with lower cumulative numbers of dead Varroa mites over the entire treatment period. Thus, the total number of dead mites observed during the monitoring of field efficacy provides information about more than just the initial level of colony infestation. The proportion of resistant mites can be modelized by a decrease of daily mortality rate influencing treatment efficacy. Management of the initial Varroa mite infestation of the colony by the beekeeper can compensate for the decrease in treatment efficacy for resistance thresholds of up to 40% of resistant mites.
CONCLUSION
Treatment efficacy depends on several parameters, including initial level of infestation, treatment period and the presence of acaricide resistance. Amitraz resistance may lead to treatment failure, even if the beekeeper is able to keep initial infestation rates low. © 2021 Society of Chemical Industry.
