Timing of acaracide treatments for control of low-level populations of Varroa destructor (Acari: Varroidae) and implications for colony performance of honey bees

2003 ◽  
Vol 135 (5) ◽  
pp. 749-763 ◽  
Author(s):  
P. Gatien ◽  
R.W. Currie
Keyword(s):  
Formic Acid ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Brood Chamber ◽  
Low Level ◽  
Need For Treatment ◽  
Honey Production ◽  
Colony Performance ◽  
The Mean ◽  
Colony Survival

AbstractThe timing of acaracide treatments for control of low-level populations of Varroa destructor Anderson et Trueman has implications for colony performance of honey bees, Apis mellifera L. (Hymenoptera: Apidae). Replicated colonies with low levels of V. destructor were left untreated, exposed to fluvalinate at each of two doses for 42 days, or exposed to three applications of formic acid, with the four treatments applied in either spring or fall. Varroa destructor densities were measured by alcohol wash and drop boards, and both gave similar estimates. Over the course of one season, the mean abundance of V. destructor increased from 0.002 to 0.11 mites per bee. Extended broodless periods during winter reduced the mean abundance of V. destructor by 28%, but mite mortality over winter was not high enough to prevent the need for treatment the following year. Apistan® was more effective than formic acid in both spring and fall treatments. Doses of one or two strips of Apistan® per colony were equally effective in spring or fall treatments. The mean abundance of V. destructor remained low throughout the season following spring treatment with either dose of Apistan®. Fall formic-acid treatments were more effective than spring treatments. Fluvalinate residues in samples of honey and wax collected from brood chambers and from honey supers were slightly higher in colonies treated with two strips of Apistan® than with one strip, but no detectible residue was found in extracted honey from 4500 commercial colonies treated in spring with Apistan® one strip per brood chamber for single or double storey hives. The levels of V. destructor in this study did not affect honey production or colony survival over winter.

Timing acaricide treatments to prevent Varroa destructor (Acari: Varroidae) from causing economic damage to honey bee colonies

2006 ◽  
Vol 138 (2) ◽  
pp. 238-252 ◽  
Author(s):  
R. W. Currie ◽  
P. Gatien
Keyword(s):  
Formic Acid ◽  
Varroa Destructor ◽  
Field Experiments ◽  
Slow Release ◽  
Economic Damage ◽  
Acarapis Woodi ◽  
Release Formulation ◽  
Honey Production ◽  
The Mean ◽  
Colony Survival

AbstractThis study consisted of two field experiments designed to assess the effects of acaricide treatment timing on the mean abundance of the mite Varroa destructor Anderson and Trueman and its impact on honey production and colony survival in honey bees, Apis mellifera L. (Hymenoptera: Apidae). In the first experiment, replicated colonies with different levels of infestation by V. destructor were given one of six treatments: untreated, with a low level of infestation by V. destructor; untreated, with a moderate level of infestation by V. destructor; exposed to fluvalinate for 42 days; exposed to two applications of Perizin®; or exposed to four applications of a pour-on formulation of formic acid at 4- or 10-day intervals. The six treatments were applied in either spring or fall. In experiment two, replicated colonies with a high level of infestation by V. destructor were left untreated, exposed to fluvalinate for 42 days, exposed to five applications of formic acid at 7-day intervals, or exposed to an equivalent amount of formic acid applied as a slow-release formulation. For each experiment, V. destructor densities, measured by alcohol wash, and colony survival were monitored for 1 year, and honey production was assessed in the year in which the spring treatment was applied. The results showed that all of the acaricide treatments were effective in reducing the mean abundance of V. destructor. However, efficacy varied with season. Fluvalinate was effective in controlling varroa under either spring or fall treatment conditions. Fall applications of Perizin® provided better control than spring applications. Formic acid provided consistent control of V. destructor in spring applications, regardless of the interval between treatments or whether pour-on or slow-release formulations were used, but was ineffective in the fall. Honey production was improved by spring acaricide treatments in both years. When the mean abundance of V. destructor was 0.02 ± 0.005 mites per bee (2 mites per 100 bees) in mid-April, honey production increased from 66 ± 17 kg per colony in untreated colonies to up to 116 ± 23 kg per colony in colonies treated with acaricide. When V. destructor levels were 0.21 ± 0.02 mites per bee (21 mites per 100 bees) in mid-May, spring acaricide treatments increased honey production from 1.3 ± 2.3 kg per untreated colony to up to 48 ± 17 kg per acaricide-treated colony. For the prairie region of Canada, producers will need to assess colonies in both spring and fall and treat when the mean abundance of V. destructor is more than 0.02 mites per bee (2 mites per 100 bees) in spring to prevent losses in honey production. Producers should treat when the mite level is greater than 0.04 mites per bee (4 mites per 100 bees) in late August to early September to prevent fall or winter colony loss. In this study, tracheal mite (Acarapis woodi (Rennie)) (Acari: Tarsonemidae) levels were very low, so interactions between mites were not studied. If both tracheal and varroa mites are present, lower fall thresholds might be required. In the absence of tracheal mites, colonies with varroa mite levels of more than 0.17 mites per bee (17 mites per 100 bees) in late fall experienced significant winter loss.

scholarly journals Efficacy and temperature dependence of 60% and 85% formic acid treatment against Varroa destructor

Apidologie ◽  
2021 ◽  
Author(s):  
Xenia STEUBE ◽  
Patricia BEINERT ◽  
Wolfgang H. KIRCHNER
Keyword(s):  
Formic Acid ◽  
Ambient Temperature ◽  
Varroa Destructor ◽  
Acid Treatment ◽  
Treatment Success ◽  
Late Summer ◽  
Active Principle ◽  
Brood Chamber ◽  
Model Treatment ◽  
Lower Variability

AbstractThe ectoparasitic mite Varroa destructor is considered one of the main threats to the western honey bee (Apis mellifera). Efficient pest management is crucial, and the evaporation of formic acid (FA) is an active principle that could be adopted. However, the usage of FA has an extreme variable efficacy depending on several conditions, ambient temperature among them. Cooler conditions, as they usually occur in Central Europe in late summer and autumn, can negatively affect treatment success. Our study aims to evaluate factors that influence the efficacy of different FA treatments. Over a period of 8 years, we investigated the effect of ambient temperature, hive size and dispenser type on the treatment success with 60% and 85% FA and consolidated those factors in a linear regression model. Treatment with 60% FA shows higher variability, and often lowered efficacy, especially in double brood chamber hives. In contrast, 85% FA treatment achieves higher efficacy and lower variability and shows significantly diminished dependence on ambient temperature.

scholarly journals To Treat or Not to Treat Bees? Handy VarLoad: A Predictive Model for Varroa destructor Load

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 678
Author(s):  
Hélène Dechatre ◽  
Lucie Michel ◽  
Samuel Soubeyrand ◽  
Alban Maisonnasse ◽  
Pierre Moreau ◽  
...  
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Early Spring ◽  
Brood Cell ◽  
Regular Treatment ◽  
Cell Numbers ◽  
Risks And Benefits ◽  
Initial Load ◽  
Colony Performance ◽  
Bee Colonies

The parasitic Varroa destructor is considered a major pathogenic threat to honey bees and to beekeeping. Without regular treatment against this mite, honey bee colonies can collapse within a 2–3-year period in temperate climates. Beyond this dramatic scenario, Varroa induces reductions in colony performance, which can have significant economic impacts for beekeepers. Unfortunately, until now, it has not been possible to predict the summer Varroa population size from its initial load in early spring. Here, we present models that use the Varroa load observed in the spring to predict the Varroa load one or three months later by using easily and quickly measurable data: phoretic Varroa load and capped brood cell numbers. Built on 1030 commercial colonies located in three regions in the south of France and sampled over a three-year period, these predictive models are tools designed to help professional beekeepers’ decision making regarding treatments against Varroa. Using these models, beekeepers will either be able to evaluate the risks and benefits of treating against Varroa or to anticipate the reduction in colony performance due to the mite during the beekeeping season.

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

Biologija ◽  
2017 ◽  
Vol 63 (2) ◽  
Author(s):  
Ataollah Rahimi ◽  
Yaser Khoram Del ◽  
Farzad Moradpour
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Ethanol Extract ◽  
Control Treatment ◽  
Varroa Mite ◽  
Brood Chamber ◽  
Synthetic Chemicals ◽  
Risk Of Mortality ◽  
Significant Difference ◽  
Varroa Mites

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.

scholarly journals Norwegian honey bees surviving Varroa destructor mite infestations by means of natural selection

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3956 ◽  
Author(s):  
Melissa A.Y. Oddie ◽  
Bjørn Dahle ◽  
Peter Neumann
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Apis Cerana ◽  
Mite Infestation ◽  
Colony Losses ◽  
Key Factor ◽  
Colony Survival

Background Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasitic mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not produced European honey bee colonies that can survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this ability by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and two potential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Results Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by 30% when compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning more from nature, i.e., identifying the obviously efficient mechanisms favored by natural selection.

scholarly journals Norwegian honey bees surviving Varroa destructor miteinfestations by means of natural selection

2017 ◽  
Author(s):  
Melissa AY Oddie ◽  
Bjørn Dahle ◽  
Peter Neumann
Keyword(s):  
Natural Selection ◽  
Reproductive Success ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Apis Cerana ◽  
Mite Infestation ◽  
Colony Losses ◽  
Key Factor ◽  
Colony Survival

Background: Managed, feral and wild populations of European honey bee subspecies, Apis mellifera, are currently facing severe colony losses globally. There is consensus that the ectoparasite mite Varroa destructor, that switched hosts from the Eastern honey bee Apis cerana to the Western honey bee A. mellifera, is a key factor driving these losses. For >20 years, breeding efforts have not achieved that European honey bee colonies survive infestations without the need for mite control. However, at least three populations of European honey bees have developed this by means of natural selection and have been surviving for >10 years without mite treatments. Reduced mite reproductive success has been suggested as a key factor explaining this natural survival. Here, we report a managed A. mellifera population in Norway, that has been naturally surviving consistent V. destructor infestations for >17 years. Methods: Surviving colonies and local susceptible controls were evaluated for mite infestation levels, mite reproductive success and twopotential mechanisms explaining colony survival: grooming of adult worker bees and Varroa Sensitive Hygiene (VSH): adult workers specifically detecting and removing mite-infested brood. Results: Mite infestation levels were significantly lower in surviving colonies and mite reproductive success was reduced by ~30% compared to the controls. No significant differences were found between surviving and control colonies for either grooming or VSH. Discussion: Our data confirm that reduced mite reproductive success seems to be a key factor for natural survival of infested A. mellifera colonies. However, neither grooming nor VSH seem to explain colony survival. Instead, other behaviors of the adult bees seem to be sufficient to hinder mite reproductive success, because brood for this experiment was taken from susceptible donor colonies only. To mitigate the global impact of V. destructor, we suggest learning more from nature, i.e. identifying the obviously efficient mechanisms favored by natural selection.

scholarly journals Three Decades of Selecting Honey Bees that Survive Infestations by the Parasitic Mite Varroa destructor: Outcomes, Limitations and Strategy

2020 ◽  
Author(s):  
Matthieu Guichard ◽  
Vincent Dietemann ◽  
Markus Neuditschko ◽  
Benjamin Dainat
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Control Strategies ◽  
Pollination Services ◽  
Colony Losses ◽  
New Host ◽  
Parasite Relationship ◽  
Parasitic Mite ◽  
Selected Traits ◽  
Colony Survival

Despite the implementation of control strategies, the invasive parasitic mite Varroa destructor remains one of the principal causes of honey bee (Apis mellifera) colony losses in numerous countries. For this reason, the parasite represents a serious threat to beekeeping and to agro-ecosystems that benefit from the pollination services provided by honey bees. Numerous selection programmes have been initiated over the last three decades with the aim of promoting the establishment of balance in the host–parasite relationship and, thus, helping European honey bees to survive in the presence of the parasite without the need for acaricide treatments. Such programmes have focused on either selective breeding for putative resistance traits or natural selection. To date, no clear overview of these attempts has been available, which has prevented building on past successes or failures and, therefore, hindered the development of a sustainable strategy for solving the V. destructor problem. In the present study, we review past and current selection strategies, report on their outcomes and discuss their limitations. Based on this state-of-the-art knowledge, we propose a strategy for increasing response to selection and colony survival against V. destructor infestations. Developing in-depth knowledge regarding the selected traits, optimising selection programmes and communicating their outcomes are all crucial to our efforts to establish a balanced relationship between the invasive parasite and its new host.

scholarly journals Can supplementary pollen feeding reduce varroa mite and virus levels and improve honey bee colony survival?

2020 ◽  
Vol 82 (4) ◽  
pp. 455-473
Author(s):  
Gloria DeGrandi-Hoffman ◽  
Vanessa Corby-Harris ◽  
Yanping Chen ◽  
Henry Graham ◽  
Mona Chambers ◽  
...  
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Colony Growth ◽  
Positive Influence ◽  
Varroa Mite ◽  
Deformed Wing Virus ◽  
Positive Effects ◽  
Bee Colony ◽  
Pollen Feeding ◽  
Colony Survival

AbstractVarroa destructor is an ectoparasitic mite of immature and adult honey bees that can transmit several single-stranded RNA viruses to its host. Varroa reproduce in brood cells, and mite populations increase as colonies produce brood in spring and summer. Mite numbers also can sharply rise, particularly in the fall, by the migration of varroa into hives on foragers. Colonies with high levels of varroa and viruses often die over the winter. Feeding colonies pollen might keep virus levels low and improve survival because of the positive effects of pollen on immunity and colony growth. We compared varroa and virus levels and overwinter survival in colonies with (fed) and without (unfed) supplemental pollen. We also measured the frequency of capturing foragers with mites (FWM) at colony entrances to determine its relationship to varroa and virus levels. Colonies fed supplemental pollen were larger than unfed colonies and survived longer. Varroa populations and levels of Deformed wing virus (DWV) rose throughout the season, and were similar between fed and unfed colonies. The growth of varroa populations was correlated with FWM in fed and unfed colonies, and significantly affected DWV levels. Increasing frequencies of FWM and the effects on varroa populations might reduce the positive influence of supplemental pollen on immune function. However, pollen feeding can stimulate colony growth and this can improve colony survival.

scholarly journals Nectar, humidity, honey bees ( Apis mellifera ) and varroa in summer: a theoretical thermofluid analysis of the fate of water vapour from honey ripening and its implications on the control of Varroa destructor

2019 ◽  
Vol 16 (156) ◽  
pp. 20190048 ◽  
Author(s):  
Derek Mitchell
Keyword(s):  
Honey Bees ◽  
Varroa Destructor ◽  
Theoretical Basis ◽  
Thermal Conductance ◽  
Honey Production ◽  
Natural Home ◽  
Nectar Concentration ◽  
Colony Collapse ◽  
Pathogenic Viruses ◽  
Brood Nest

This theoretical thermofluid analysis investigates the relationships between honey production rate, nectar concentration and the parameters of entrance size, nest thermal conductance, brood nest humidity and the temperatures needed for nectar to honey conversion. It quantifies and shows that nest humidity is positively related to the amount, and water content of the nectar being desiccated into honey and negatively with respect to nest thermal conductance and entrance size. It is highly likely that honeybees, in temperate climates and in their natural home, with much smaller thermal conductance and entrance, can achieve higher humidities more easily and more frequently than in man-made hives. As a consequence, it is possible that Varroa destructor , a parasite implicated in the spread of pathogenic viruses and colony collapse, which loses fecundity at absolute humidities of 4.3 kPa (approx. 30 gm −3 ) and above, is impacted by the more frequent occurrence of higher humidities in these low conductance, small entrance nests. This study provides the theoretical basis for new avenues of research into the control of varroa, via the modification of beekeeping practices to help maintain higher hive humidities.

scholarly journals Using Citizen Science to Scout Honey Bee Colonies that Naturally Survive Varroa destructor Infestations

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 536
Author(s):  
Arrigo Moro ◽  
Alexis Beaurepaire ◽  
Raffaele Dall’Olio ◽  
Steve Rogenstein ◽  
Tjeerd Blacquière ◽  
...  
Keyword(s):  
Citizen Science ◽  
Honey Bee ◽  
Honey Bees ◽  
Varroa Destructor ◽  
Control Strategies ◽  
Conservation Status ◽  
Free Living ◽  
Successful Recruitment ◽  
Mite Control ◽  
Colony Survival

Citizen Science contributes significantly to the conservation of biodiversity, but its application to honey bee research has remained minimal. Even though certain European honey bee (Apis mellifera) populations are known to naturally survive Varroa destructor infestations, it is unclear how widespread or common such populations are. Such colonies are highly valuable for investigating the mechanisms enabling colony survival, as well as for tracking the conservation status of free-living honey bees. Here, we use targeted Citizen Science to identify potentially new cases of managed or free-living A. mellifera populations that survive V. destructor without mite control strategies. In 2018, a survey containing 20 questions was developed, translated into 13 languages, and promoted at beekeeping conferences and online. After three years, 305 reports were collected from 28 countries: 241 from managed colonies and 64 from free-living colonies. The collected data suggest that there could be twice as many naturally surviving colonies worldwide than are currently known. Further, online and personal promotion seem to be key for successful recruitment of participants. Although the survivor status of these colonies still needs to be confirmed, the volume of reports and responses already illustrate how effectively Citizen Science can contribute to bee research by massively increasing generated data, broadening opportunities for comparative research, and fostering collaboration between scientists, beekeepers, and citizens. The success of this survey spurred the development of a more advanced Citizen Science platform, Honey Bee Watch, that will enable a more accurate reporting, confirmation, and monitoring of surviving colonies, and strengthen the ties between science, stakeholders, and citizens to foster the protection of both free-living and managed honey bees.

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