Effectiveness of Different Soft Acaricides against Honey Bee Ectoparasitic Mite Varroa destructor (Acari: Varroidae)

Honey bees (Apis mellifera) are essential for their products—honey, royal jelly, pollen, propolis and beeswax. They are also indispensable because they support ecosystems with their pollination services. However, the production and functions of honey bees are hindered by the arthropod pest Varroa destructor, which attacks bees through its feeding activities. Efforts to control varroa mites have been made through the development of various synthetic pesticide groups, but have had limited success because the mites developed resistance and some of these pesticides are harmful to bees. Branded pesticides are rarely used in Pakistan, as beekeepers utilize acaricides from unknown sources. There is a need to create awareness of available naturally occurring acaricides that may serve as an alternative to synthetic acaricides. Although some naturally occurring compounds are considered toxic to the environment, the soft acaricides oxalic acid, thymol, and formic acid 65% are usually safe for honey bee colonies and beekeepers, when handled appropriately. The current study investigated the effectiveness of formic acid (10, 15, and 20 mL/hive), oxalic acid (4.2, 3.2, and 2.1%/hive), and thymol (6, 4, and 2 g/hive) in controlling mite infestation. The results indicated that all treatments significantly reduced the mite population (p < 0.05). The average efficacies of oxalic acid at 3.2% (94.84% ± 0.34) and 4.2% (92.68% ± 0.37) were significantly higher than those of the other treatments. The lowest efficacy was recorded in formic acid 65% at 10 mL (54.13%). Overall, the results indicated that soft acaricides—such as oxalic acid at 3.2% and 4.2% concentrations—are very effective at controlling varroa mites and can be used in broodless conditions without side effects.

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Advances and perspectives in selecting resistance traits against the parasitic mite Varroa destructor in honey bees

Genetics Selection Evolution ◽

10.1186/s12711-020-00591-1 ◽

2020 ◽

Vol 52 (1) ◽

Cited By ~ 1

Author(s):

Matthieu Guichard ◽

Vincent Dietemann ◽

Markus Neuditschko ◽

Benjamin Dainat

Keyword(s):

Honey Bee ◽

Environmental Effects ◽

Honey Bees ◽

Varroa Destructor ◽

Selection Strategy ◽

Pollination Services ◽

Colony Losses ◽

New Host ◽

Parasitic Mite ◽

Resistance Traits

Abstract Background In spite of the implementation of control strategies in honey bee (Apis mellifera) keeping, the invasive parasitic mite Varroa destructor remains one of the main causes of colony losses in numerous countries. Therefore, this parasite represents a serious threat to beekeeping and agro-ecosystems that benefit from the pollination services provided by honey bees. To maintain their stocks, beekeepers have to treat their colonies with acaricides every year. Selecting lineages that are resistant to infestations is deemed to be a more sustainable approach. Review Over the last three decades, numerous selection programs have been initiated to improve the host–parasite relationship and to support honey bee survival in the presence of the parasite without the need for acaricide treatments. Although resistance traits have been included in the selection strategy of honey bees, it has not been possible to globally solve the V. destructor problem. In this study, we review the literature on the reasons that have potentially limited the success of such selection programs. We compile the available information to assess the relevance of selected traits and the potential environmental effects that distort trait expression and colony survival. Limitations to the implementation of these traits in the field are also discussed. Conclusions Improving our knowledge of the mechanisms underlying resistance to V. destructor to increase trait relevance, optimizing selection programs to reduce environmental effects, and communicating selection outcomes are all crucial to efforts aiming at establishing a balanced relationship between the invasive parasite and its new host.

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Brood removal or queen caging combined with oxalic acid treatment to control varroa mites (Varroa destructor) in honey bee colonies (Apis mellifera)

Apidologie ◽

10.1007/s13592-017-0526-2 ◽

2017 ◽

Vol 48 (6) ◽

pp. 821-832 ◽

Cited By ~ 15

Author(s):

Aleš Gregorc ◽

Mohamed Alburaki ◽

Chris Werle ◽

Patricia R. Knight ◽

John Adamczyk

Keyword(s):

Apis Mellifera ◽

Oxalic Acid ◽

Honey Bee ◽

Varroa Destructor ◽

Acid Treatment ◽

Varroa Mites ◽

Bee Colonies

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Powdered sugar shake to monitor and oxalic acid treatments to control varroa mites (Varroa destructor Anderson and Trueman) in honey bee (Apis mellifera) colonies

Journal of Apicultural Research ◽

10.1080/00218839.2017.1278912 ◽

2017 ◽

Vol 56 (1) ◽

pp. 71-75 ◽

Cited By ~ 6

Author(s):

Ales Gregorc ◽

Patricia R Knight ◽

John Adamczyk

Keyword(s):

Apis Mellifera ◽

Oxalic Acid ◽

Honey Bee ◽

Varroa Destructor ◽

Varroa Mites ◽

Acid Treatments

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Comparative transcriptomics indicates endogenous differences in detoxification capacity after formic acid treatment between honey bees and varroa mites

Scientific Reports ◽

10.1038/s41598-020-79057-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Antonia Genath ◽

Soroush Sharbati ◽

Benjamin Buer ◽

Ralf Nauen ◽

Ralf Einspanier

Keyword(s):

Formic Acid ◽

Honey Bee ◽

Honey Bees ◽

Mode Of Action ◽

Developmental Stages ◽

Cellular Respiration ◽

Current View ◽

Cellular Effects ◽

Varroa Mites ◽

Formyltetrahydrofolate Dehydrogenase

AbstractFormic acid (FA) has been used for decades to control Varroa destructor, one of the most important parasites of the western honey bee, Apis mellifera. The rather unselective molecular mode of action of FA and its possible effects on honeybees have long been a concern of beekeepers, as it has undesirable side effects that affect the health of bee colonies. This study focuses on short-term transcriptomic changes as analysed by RNAseq in both larval and adult honey bees and in mites after FA treatment under applied conditions. Our study aims to identify those genes in honey bees and varroa mites differentially expressed upon a typical FA hive exposure scenario. Five detoxification-related genes were identified with significantly enhanced and one gene with significantly decreased expression under FA exposure. Regulated genes in our test setting included members of various cytochrome P450 subfamilies, a flavin-dependent monooxygenase and a cytosolic 10-formyltetrahydrofolate dehydrogenase (FDH), known to be involved in formate metabolism in mammals. We were able to detect differences in the regulation of detoxification-associated genes between mites and honey bees as well as between the two different developmental stages of the honey bee. Additionally, we detected repressed regulation of Varroa genes involved in cellular respiration, suggesting mitochondrial dysfunction and supporting the current view on the mode of action of FA—inhibition of oxidative phosphorylation. This study shows distinct cellular effects induced by FA on the global transcriptome of both host and parasite in comparison. Our expression data might help to identify possible differences in the affected metabolic pathways and thus make a first contribution to elucidate the mode of detoxification of FA.

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Reproduction of Distinct Varroa destructor Genotypes on Honey Bee Worker Brood

Insects ◽

10.3390/insects10110372 ◽

2019 ◽

Vol 10 (11) ◽

pp. 372 ◽

Cited By ~ 1

Author(s):

Wenfeng Li ◽

Cheng Wang ◽

Zachary Y. Huang ◽

Yanping Chen ◽

Richou Han

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Southern China ◽

Reproductive Rate ◽

Wild Plants ◽

Dependent Manner ◽

New Host ◽

Varroa Mites ◽

Worker Brood

Honey bees play important roles in pollination for many crops and wild plants, but have been facing great threats posed by various pathogens and parasites. Among them, Varroa destructor, an obligate ectoparasite of honey bees, is considered the most damaging. Within the last century, V. destructor shifted from the original host, the Asian honey bee Apis cerana to the new host, the European honey bee A. mellifera. However, the reproduction of Varroa mites, especially of different haplotypes in the two hosts, is still largely unknown. In this study, we first investigated the existing Varroa haplotypes in local colonies in southern China, and then compared the reproduction of different haplotypes on the worker brood of both the original and new hosts by artificial inoculation. We confirmed that there are two haplotypes of V. destructor in southern China, one is the Korea haplotype and the other is the China haplotype, and the two types parasitized different honey bee species. Although Varroa females from A. mellifera (Korea haplotype) are able to reproduce on the worker brood of both honey bee species, they showed better reproductive performance in the new host A. mellifera with significantly higher fecundity (number of offspring per mother mite) and reproductive rate (number of adult daughters per mother mite), suggesting that this parasite gains higher fitness after host shift. The data further showed that a short stay of Varroa females inside the A. cerana worker cells decreased their fecundity and especially the reproductive rate in a time-dependent manner, suggesting that the A. cerana worker cells may inhibit Varroa reproduction. In contrast, Varroa mites derived from A. cerana colonies (China haplotype) were entirely sterile in A. mellifera worker cells during two sequential inoculations, while the control mites from A. mellifera colonies (Korea haplotype) reproduced normally. In addition, all the infertile mites were found to defecate on the abdomen of bee pupae. We have revealed that two haplotypes of V. destructor exhibit differential reproduction on the worker brood of the original and new host honey bees, providing novel insights into the diversity and complexity of the reproduction of V. destructor.

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Liquid formic acid 60% to control varroa mites (Varroa destructor) in honey bee colonies (Apis mellifera): protocol evaluation

Journal of Apicultural Research ◽

10.1080/00218839.2017.1376767 ◽

2017 ◽

Vol 57 (2) ◽

pp. 300-307 ◽

Cited By ~ 2

Author(s):

Marco Pietropaoli ◽

Giovanni Formato

Keyword(s):

Apis Mellifera ◽

Formic Acid ◽

Honey Bee ◽

Varroa Destructor ◽

Varroa Mites ◽

Protocol Evaluation ◽

Bee Colonies

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A New Strain of Virus Discovered in China Specific to the Parasitic Mite Varroa destructor Poses a Potential Threat to Honey Bees

Viruses ◽

10.3390/v13040679 ◽

2021 ◽

Vol 13 (4) ◽

pp. 679

Author(s):

Gongwen Chen ◽

Shuai Wang ◽

Shuo Jia ◽

Ye Feng ◽

Fuliang Hu ◽

...

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Molecular Mechanisms ◽

Evolutionary Dynamics ◽

Apis Cerana ◽

Potential Threat ◽

Chinese Strain ◽

Illumina Hiseq ◽

Varroa Mites

The ectoparasitic mite, Varroa destructor, feeds directly on honey bees and serves as a vector for transmitting viruses among them. The Varroa mite causes relatively little damage to its natural host, the Eastern honey bee (Apis cerana) but it is the most devastating pest for the Western honey bee (Apis mellifera). Using Illumina HiSeq sequencing technology, we conducted a metatranscriptome analysis of the microbial community associated with Varroa mites. This study led to the identification of a new Chinese strain of Varroa destructor virus-2 (VDV-2), which is a member of the Iflaviridae family and was previously reported to be specific to Varroa mites. A subsequent epidemiological investigation of Chinese strain of VDV-2 (VDV-2-China) showed that the virus was highly prevalent among Varroa populations and was not identified in any of the adult workers from both A. mellifera and A.cerana colonies distributed in six provinces in China, clearly indicating that VDV-2-China is predominantly a Varroa-adapted virus. While A. mellifera worker pupae exposed to less than two Varroa mites tested negative for VDV-2-China, VDV-2-China was detected in 12.5% of the A. mellifera worker pupae that were parasitized by more than 10 Varroa mites, bringing into play the possibility of a new scenario where VDV-2 could be transmitted to the honey bees during heavy Varroa infestations. Bioassay for the VDV-2-China infectivity showed that A. cerana was not a permissive host for VDV-2-China, yet A. mellifera could be a biological host that supports VDV-2-China’s replication. The different replication dynamics of the virus between the two host species reflect their variation in terms of susceptibility to the virus infection, posing a potential threat to the health of the Western honey bee. The information gained from this study contributes to the knowledge concerning genetic variabilities and evolutionary dynamics of Varroa-borne viruses, thereby enhancing our understanding of underlying molecular mechanisms governing honey bee Varroosis.

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Parasitic mites and microsporidians in managed western honey bee colonies on the island of Newfoundland, Canada

The Canadian Entomologist ◽

10.4039/n10-029 ◽

2010 ◽

Vol 142 (6) ◽

pp. 584-588 ◽

Cited By ~ 4

Author(s):

Geoffrey R. Williams ◽

Krista Head ◽

Karen L. Burgher-MacLellan ◽

Richard E.L. Rogers ◽

Dave Shutler

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Geographic Isolation ◽

Acarapis Woodi ◽

Pollination Services ◽

Chemical Treatments ◽

Organic Honey ◽

Parasitic Mites ◽

Bee Colonies

AbstractWestern honey bees, Apis mellifera L. (Hymenoptera: Apidae), occur in nearly every region inhabited by man because they provide valuable honey, wax, and pollination services. Many commercial honey bee operations are plagued by economically important parasites; however, beekeepers on the island of Newfoundland, Canada, are in a unique position because of the province of Newfoundland and Labrador’s strict import regulations and geographic isolation. We surveyed about 25% of the island’s approximately 100 managed honey bee colonies. The parasitic mites Varroa destructor Anderson and Trueman (Acari: Varroidae) and Acarapis woodi (Rennie) (Acari: Tarsonemidae) were not detected, whereas Nosema spp. microsporidia were detected in two of four beekeeping operations and in 11 of 23 (48%) colonies (intensity = 482 609 ± 1199 489 (mean ± SD); median intensity = 0). Because V. destructor and A. woodi are important pests that typically require chemical treatments, beekeepers on the island of Newfoundland may be uniquely positioned to market organic honey bee products from colonies that could also be a source of mite-naïve bees for research.

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Exploring Two Honey Bee Traits for Improving Resistance Against Varroa destructor: Development and Genetic Evaluation

Insects ◽

10.3390/insects12030216 ◽

2021 ◽

Vol 12 (3) ◽

pp. 216

Author(s):

Matthieu Guichard ◽

Benoît Droz ◽

Evert W. Brascamp ◽

Adrien von Virag ◽

Markus Neuditschko ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Field Trial ◽

Genetic Evaluation ◽

Phenotypic Correlation ◽

Apis Mellifera Mellifera ◽

Novel Traits ◽

Resistance Traits

For the development of novel selection traits in honey bees, applicability under field conditions is crucial. We thus evaluated two novel traits intended to provide resistance against the ectoparasitic mite Varroa destructor and to allow for their straightforward implementation in honey bee selection. These traits are new field estimates of already-described colony traits: brood recapping rate (‘Recapping’) and solidness (‘Solidness’). ‘Recapping’ refers to a specific worker characteristic wherein they reseal a capped and partly opened cell containing a pupa, whilst ‘Solidness’ assesses the percentage of capped brood in a predefined area. According to the literature and beekeepers’ experiences, a higher recapping rate and higher solidness could be related to resistance to V. destructor. During a four-year field trial in Switzerland, the two resistance traits were assessed in a total of 121 colonies of Apis mellifera mellifera. We estimated the repeatability and the heritability of the two traits and determined their phenotypic correlations with commonly applied selection traits, including other putative resistance traits. Both traits showed low repeatability between different measurements within each year. ‘Recapping’ had a low heritability (h2 = 0.04 to 0.05, depending on the selected model) and a negative phenotypic correlation to non-removal of pin-killed brood (r = −0.23). The heritability of ‘Solidness’ was moderate (h2 = 0.24 to 0.25) and did not significantly correlate with resistance traits. The two traits did not show an association with V. destructor infestation levels. Further research is needed to confirm the results, as only a small number of colonies was evaluated.

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