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

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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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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Evaluation of potential miticide toxicity to Varroa destructor and honey bees, Apis mellifera, under laboratory conditions

Scientific Reports ◽

10.1038/s41598-020-78561-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Rassol Bahreini ◽

Medhat Nasr ◽

Cassandra Docherty ◽

Olivia de Herdt ◽

Samantha Muirhead ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

High Dose ◽

Agricultural Crops ◽

High Toxicity ◽

High Efficacy ◽

Dose Rates ◽

Colony Level

AbstractThe honey bee, Apis mellifera L., is the world’s most important managed pollinator of agricultural crops, however, Varroa mite, Varroa destructor Anderson and Trueman, infestation has threatened honey bee survivorship. Low efficacy and development of Varroa mite resistance to currently used Varroacides has increased the demand for innovative, effective treatment tool options that exhibit high efficacy, while minimizing adverse effects on honey bee fitness. In this investigation, the toxicity of 16 active ingredients and 9 formulated products of registered miticides for use on crops from 12 chemical families were evaluated in comparison to amitraz on Varroa mites and honey bees using contact surface and topical exposures. It was found that fenpyroximate (93% mortality), spirotetramat (84% mortality) and spirodiclofen (70% mortality) had greater toxicity to Varroa mites, but high dose rates caused high bee mortality (> 60%). With this in mind, further research is needed to investigate other options to minimize the adverse effect of these compounds on bees. The results also found high toxicity of fenazaquin and etoxazole against Varroa mites causing 92% and 69% mortality, respectively; and were found to be safe on honey bees. Collectively, it is recommended that fenazaquin and etoxazole are candidates for a potential Varroacide and recommended for further testing against Varroa mites at the colony level.

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Ten Years of Deformed Wing Virus (DWV) in Hawaiian Honey Bees (Apis mellifera), the Dominant DWV-A Variant Is Potentially Being Replaced by Variants with a DWV-B Coding Sequence

Viruses ◽

10.3390/v13060969 ◽

2021 ◽

Vol 13 (6) ◽

pp. 969

Author(s):

Isobel Grindrod ◽

Jessica L. Kevill ◽

Ethel M. Villalobos ◽

Declan C. Schroeder ◽

Stephen John Martin

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Original Study ◽

Viral Diversity ◽

Deformed Wing Virus ◽

Complete Dominance ◽

Coding Sequence ◽

Bee Colonies

The combination of Deformed wing virus (DWV) and Varroa destructor is arguably one of the greatest threats currently facing western honey bees, Apis mellifera. Varroa’s association with DWV has decreased viral diversity and increased loads of DWV within honey bee populations. Nowhere has this been better studied than in Hawaii, where the arrival of Varroa progressively led to the dominance of the single master variant (DWV-A) on both mite-infested Hawaiian Islands of Oahu and Big Island. Now, exactly 10 years following the original study, we find that the DWV population has changed once again, with variants containing the RdRp coding sequence pertaining to the master variant B beginning to co-dominate alongside variants with the DWV-A RdRp sequence on the mite-infested islands of Oahu and Big Island. In speculation, based on other studies, it appears this could represent a stage in the journey towards the complete dominance of DWV-B, a variant that appears better adapted to be transmitted within honey bee colonies.

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Synergistic and Antagonistic Interactions Between Varroa destructor Mites and Neonicotinoid Insecticides in Male Apis mellifera Honey Bees

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.756027 ◽

2021 ◽

Vol 9 ◽

Author(s):

Selina Bruckner ◽

Lars Straub ◽

Peter Neumann ◽

Geoffrey R. Williams

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Sperm Quality ◽

Sperm Concentration ◽

Negative Consequences ◽

Mature Adult ◽

Age Cohorts ◽

Bee Colony

Pressures from multiple, sometimes interacting, stressors can have negative consequences to important ecosystem-service providing species like the western honey bee (Apis mellifera). The introduced parasite Varroa destructor and the neonicotinoid class of insecticides each represent important, nearly ubiquitous biotic and abiotic stressors to honey bees, respectively. Previous research demonstrated that they can synergistically interact to negatively affect non-reproductive honey bee female workers, but no data exist on how concurrent exposure may affect reproductive honey bee males (drones). This is important, given that the health of reproductive females (queens), possibly because of poor mating, is frequently cited as a major driver of honey bee colony loss. To address this, known age cohorts of drones were obtained from 12 honey bee colonies—seven were exposed to field-relevant concentrations of two neonicotinoids (4.5 ppb thiamethoxam and 1.5 ppb clothianidin) during development via supplementary pollen patties; five colonies received patties not spiked with neonicotinoids. Artificially emerged drones were assessed for natural V. destructor infestation, weighed, and then allocated to the following treatment groups: 1. Control, 2. V. destructor only, 3. Neonicotinoid only, and 4. Combined (both mites and neonicotinoid). Adult drones were maintained in laboratory cages alongside attendant workers (1 drone: 2 worker ratio) until they have reached sexual maturity after 14 days so sperm concentration and viability could be assessed. The data suggest that V. destructor and neonicotinoids interacted synergistically to negatively affect adult drone survival, but that they interacted antagonistically on emergence mass. Although sample sizes were too low to assess the effects of V. destructor and combined exposure on sperm quality, we observed no influence of neonicotinoids on sperm concentration or viability. Our findings highlight the diverse effects of concurrent exposure to stressors on honey bees, and suggest that V. destructor and neonicotinoids can severely affect the number of sexually mature adult drones available for mating.

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Nosema Ceranae DNA in Honey Bee Haemolymph and Honey Bee Mite Varroa Destructor/DNK Nosema Ceranae U Hemolimfi Pčela I Pčelinjem Krpelju Varroa Destructor

Acta veterinaria ◽

10.2478/acve-2014-0033 ◽

2014 ◽

Vol 64 (3) ◽

pp. 349-357 ◽

Cited By ~ 6

Author(s):

Glavinić Uroš ◽

Stevanović Jevrosima ◽

Gajić Bojan ◽

Simeunović Predrag ◽

Đurić Spomenka ◽

...

Keyword(s):

Apis Mellifera ◽

Epithelial Cells ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Dna Isolation ◽

Nosema Ceranae ◽

Knowing That ◽

Mite Feeding

Abstract Honey bee mite Varroa destructor and microsporidium Nosema ceranae are currently considered the most important threats to honey bees and beekeeping. It has been believed that both N. apis and N. ceranae invade exclusively epithelial cells of the honey bee ventriculus. However, some fi ndings suggest that these microsporidia may infect other tissues of honey bees. There are indications that these pathogens could be found in honey bee haemolymph, as the medium for its distribution to anatomically distant tissues. Knowing that V. destructor being an ectoparasitic mite feeds on the honey bee’s haemolymph, the aim of this study was to investigate if DNA of Nosema spp. microsporidia could be found in honey bee haemolymph and in V. destructor. The study was conducted on bee haemolymph and V. destructor mites from 44 Apis mellifera colonies. From each hive five mite individuals and 10 μL of haemolymph (from 4-5 bees) were used as samples for DNA isolation and PCR detection of Nosema spp. The DNA of N. ceranae was confi rmed in 61.36% of V. destructor mites and 68.18% of haemolymph samples. This is the first report of N. ceranae DNA in honey bee haemolymph and in V. destructor mites. The finding of DNA of N. ceranae in V. destructor could be interpreted as the result of mite feeding on N. ceranae infected bee haemolymph. However, for a full confi rmation of the vector role of V. destructor in spreading of nosemosis, further microscopy investigations are required for the detection of spores in both investigated matrices (haemolymph and V. destructor internal tissues).

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How to quantify Varroa destructor in honey bee (Apis mellifera L.) colonies

EDIS ◽

10.32473/edis-in1257-2019 ◽

2020 ◽

Vol 2020 (1) ◽

pp. 8

Author(s):

Cameron Jack ◽

Nathan Sperry ◽

Ashley N. Mortensen ◽

Jamie Ellis

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Fact Sheet ◽

Bee Colonies

The Varroa destructor mite, a devastating pest of western honey bees, can threaten a honey bee colony’s survival if it is left uncontrolled. This 8-page fact sheet written by Cameron Jack, Nathan Sperry, Ashley N. Mortensen, and Jamie Ellis and published by the UF/IFAS Entomology and Nematology Department explains how to monitor honey bee colonies to ensure that infestations of these destructive pests do not grow to dangerous levels.https://edis.ifas.ufl.edu/in1257

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Varroa destructor: how does it harm Apis mellifera honey bees and what can be done about it?

Emerging Topics in Life Sciences ◽

10.1042/etls20190125 ◽

2020 ◽

Vol 4 (1) ◽

pp. 45-57 ◽

Cited By ~ 6

Author(s):

Amélie Noël ◽

Yves Le Conte ◽

Fanny Mondet

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Abiotic Factors ◽

Apis Cerana ◽

Management Strategies ◽

Special Focus ◽

Asian Honey Bee ◽

The Individual

Since its migration from the Asian honey bee (Apis cerana) to the European honey bee (Apis mellifera), the ectoparasitic mite Varroa destructor has emerged as a major issue for beekeeping worldwide. Due to a short history of coevolution, the host–parasite relationship between A. mellifera and V. destructor is unbalanced, with honey bees suffering infestation effects at the individual, colony and population levels. Several control solutions have been developed to tackle the colony and production losses due to Varroa, but the burden caused by the mite in combination with other biotic and abiotic factors continues to increase, weakening the beekeeping industry. In this synthetic review, we highlight the main advances made between 2015 and 2020 on V. destructor biology and its impact on the health of the honey bee, A. mellifera. We also describe the main control solutions that are currently available to fight the mite and place a special focus on new methodological developments, which point to integrated pest management strategies for the control of Varroa in honey bee colonies.

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Toxicity of Selected Acaricides to Honey Bees (Apis mellifera) and Varroa (Varroa destructor Anderson and Trueman) and Their Use in Controlling Varroa within Honey Bee Colonies

Insects ◽

10.3390/insects9020055 ◽

2018 ◽

Vol 9 (2) ◽

pp. 55 ◽

Cited By ~ 13

Author(s):

Aleš Gregorc ◽

Mohamed Alburaki ◽

Blair Sampson ◽

Patricia R. Knight ◽

John Adamczyk

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Bee Colonies

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Survey of feral honey bee (Apis mellifera) colonies for Nosema apis in Western Australia

Australian Journal of Experimental Agriculture ◽

10.1071/ea04222 ◽

2007 ◽

Vol 47 (7) ◽

pp. 883 ◽

Cited By ~ 7

Author(s):

Rob Manning ◽

Kate Lancaster ◽

April Rutkay ◽

Linda Eaton

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Western Australia ◽

Honey Bees ◽

Nosema Apis ◽

The South ◽

South West ◽

Feral Populations ◽

Significant Difference

The parasite, Nosema apis, was found to be widespread among feral populations of honey bees (Apis mellifera) in the south-west of Western Australia. The location, month of collection and whether the feral colony was enclosed in an object or exposed to the environment, all affected the presence and severity of infection. There was no significant difference in the probability of infection between managed and feral bees. However, when infected by N. apis, managed bees appeared to have a greater severity of the infection.

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