Neonicotinoid Clothianidin reduces honey bee immune response and contributes to Varroa mite proliferation

AbstractThe neonicotinoid Clothianidin has a negative impact on NF-κB signaling and on immune responses controlled by this transcription factor, which can boost the proliferation of honey bee parasites and pathogens. This effect has been well documented for the replication of deformed wing virus (DWV) induced by Clothianidin in honey bees bearing an asymptomatic infection. Here, we conduct infestation experiments of treated bees to show that the immune-suppression exerted by Clothianidin is associated with an enhanced fertility of the parasitic mite Varroa destructor, as a possible consequence of a higher feeding efficiency. A conceptual model is proposed to describe the synergistic interactions among different stress agents acting on honey bees.

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Biology and Management of Varroa destructor (Mesostigmata: Varroidae) in Apis mellifera (Hymenoptera: Apidae) Colonies

Journal of Integrated Pest Management ◽

10.1093/jipm/pmz036 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 2

Author(s):

Morgan A Roth ◽

James M Wilson ◽

Keith R Tignor ◽

Aaron D Gross

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Varroa Destructor ◽

Sampling Methods ◽

Apis Cerana ◽

Varroa Mite ◽

Resistance Development ◽

Deformed Wing Virus ◽

The Past ◽

Asian Honey Bee

Abstract Varroa mite (Varroa destructor Anderson and Trueman) infestation of European honey bee (Apis mellifera L.) colonies has been a growing cause of international concern among beekeepers throughout the last 50 yr. Varroa destructor spread from the Asian honey bee (Apis cerana Fabricius [Hymenoptera: Apidae]) to A. mellifera populations in Europe in the 1970s, and subsequently traveled to the Americas. In addition to causing damage through feeding upon lipids of larval and adult bees, V. destructor also facilitates the spread of several viruses, with deformed wing virus being most prevalent. Several sampling methods have been developed for estimating infestation levels of A. mellifera colonies, and acaricide treatments have been implemented. However, overuse of synthetic acaricides in the past has led to widespread acaricide resistant V. destructor populations. The application of Integrated Pest Management (IPM) techniques is a more recent development in V. destructor control and is suggested to be more effective than only using pesticides, thereby posing fewer threats to A. mellifera colonies. When using IPM methods, informed management decisions are made based upon sampling, and cultural and mechanical controls are implemented prior to use of acaricide treatments. If acaricides are deemed necessary, they are rotated based on their mode of action, thus avoiding V. destructor resistance development.

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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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Impacts of Diverse Natural Products on Honey Bee Viral Loads and Health

Applied Sciences ◽

10.3390/app112210732 ◽

2021 ◽

Vol 11 (22) ◽

pp. 10732

Author(s):

Dawn L. Boncristiani ◽

James P. Tauber ◽

Evan C. Palmer-Young ◽

Lianfei Cao ◽

William Collins ◽

...

Keyword(s):

Natural Products ◽

Immune Responses ◽

Honey Bee ◽

Honey Bees ◽

Food Sources ◽

Deformed Wing Virus ◽

Bee Health ◽

Honey Bee Health ◽

Living Organisms ◽

Bee Disease

Western honey bees (Apis mellifera), a cornerstone to crop pollination in the U.S., are faced with an onslaught of challenges from diseases caused by parasites, pathogens, and pests that affect this economically valuable pollinator. Natural products (NPs), produced by living organisms, including plants and microorganisms, can support health and combat disease in animals. NPs include both native extracts and individual compounds that can reduce disease impacts by supporting immunity or directly inhibiting pathogens, pests, and parasites. Herein, we describe the screening of NPs in laboratory cage studies for their effects on honey bee disease prevention and control. Depending on the expected activity of compounds, we measured varied responses, including viral levels, honey bee immune responses, and symbiotic bacteria loads. Of the NPs screened, several compounds demonstrated beneficial activities in honey bees by reducing levels of the critical honey bee virus deformed wing virus (DWV-A and-B), positively impacting the gut microbiome or stimulating honey bee immune responses. Investigations of the medicinal properties of NPs in honey bees will contribute to a better understanding of their potential to support honey bee immunity to fight off pests and pathogens and promote increased overall honey bee health. These investigations will also shed light on the ecological interactions between pollinators and specific floral food sources.

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Deformed wing virus type A, a major honey bee pathogen, is vectored by the mite Varroa destructor in a non-propagative manner

10.1101/660985 ◽

2019 ◽

Author(s):

Francisco Posada-Florez ◽

Anna K. Childers ◽

Matthew C. Heerman ◽

Noble I. Egekwu ◽

Steven C. Cook ◽

...

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Rna Virus ◽

Fold Increase ◽

Type A ◽

Deformed Wing Virus ◽

Negative Strand ◽

Viral Loads ◽

Insect Pollinator

AbstractHoney bees, the primary managed insect pollinator, suffer considerable losses due to Deformed wing virus (DWV), an RNA virus vectored by the mite Varroa destructor. Mite vectoring has resulted in the emergence of virulent DWV variants. The basis for such changes in DWV is poorly understood. Most importantly, it remains unclear whether replication of DWV occurs in the mite. In this study, we exposed Varroa mites to DWV type A via feeding on artificially infected honey bees. A significant, 357-fold increase in DWV load was observed in these mites after 2 days. However, after 8 additional days of passage on honey bee pupae with low viral loads, the DWV load dropped by 29-fold. This decrease significantly reduced the mites’ ability to transmit DWV to honey bees. Notably, negative-strand DWV RNA, which could indicate viral replication, was detected only in mites collected from pupae with high DWV levels but not in the passaged mites. We also found that Varroa mites contain honey bee mRNAs, consistent with the acquisition of honey bee cells which would additionally contain DWV replication complexes with negative-strand DWV RNA. We propose that transmission of DWV type A by Varroa mites occurs in a non-propagative manner.

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How Crucial is the Functional Pit Organ for the Varroa Mite?

Insects ◽

10.3390/insects11060395 ◽

2020 ◽

Vol 11 (6) ◽

pp. 395

Author(s):

Beatrice T. Nganso ◽

Kannan Mani ◽

Yam Altman ◽

Ada Rafaeli ◽

Victoria Soroker

Keyword(s):

Honey Bees ◽

Varroa Destructor ◽

Varroa Mite ◽

Altered Expression ◽

Pit Organ ◽

Vitellogenin Receptor ◽

Animal Survival ◽

Nail Polish ◽

Parasitic Mite ◽

Lower Ability

Olfaction as well as gustation, are essential for animal survival, allowing behavioral modulation according to environmental input. We focused our study on an obligate ecto-parasitic mite of honey bees, the Varroa destructor Anderson and Trueman (Parasitiformes, Mesostigmata, Varroidae). By mechanically blocking the main olfactory organ on Varroa forelegs by varnishing with nail polish, we were able to show that other sensory organs cannot significantly compensate chemosensory abilities required for mite’s host selection, identification as well as reproduction. In fact, we found that mites with blocked forelegs had a significantly lower ability to reach a host bee than those with varnished idiosoma and unvarnished control. Furthermore, fewer foreleg blocked mites were feeding on the nurse bees and their reproduction in the brood cells was significantly impaired. The inhibition of reproduction was also reflected in altered expression levels of vitellogenin and vitellogenin receptor genes in foreleg-blocked mites.

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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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Toxicity of Anethole and the Essential Oils of Lemongrass and Sweet Marigold to the Parasitic Mite Varroa destructor and Their Selectivity for Honey Bee (Apis mellifera) Workers and Larvae

Psyche A Journal of Entomology ◽

10.1155/2018/6196289 ◽

2018 ◽

Vol 2018 ◽

pp. 1-8

Author(s):

Qodratollah Sabahi ◽

Mollah Md. Hamiduzzaman ◽

Juan S. Barajas-Pérez ◽

Jose M. Tapia-Gonzalez ◽

Ernesto Guzman-Novoa

Keyword(s):

Essential Oils ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Acetyl Cholinesterase ◽

Cymbopogon Citratus ◽

Toxic Compound ◽

Parasitic Mite ◽

Detoxifying Enzyme ◽

Honey Bee Workers

This study examined the toxicity of anethole and that of the essential oils of lemongrass (Cymbopogon citratus) and sweet marigold (Tagetes lucida) to the mite Varroa destructor and to honey bee workers and larvae. Anethole was the most toxic compound to V. destructor (LC50: 304.9 μg/ml), whereas Tagetes oil was the least toxic (LC50: 1256.27 μg/ml). The most and least toxic compounds to worker bees were anethole and Tagetes oil with LD50s of 35942 and 85381 μg/ml, respectively. For larvae, Tagetes oil was the most toxic compound (LD50: 9580.7 μg/ml) and anethole the least toxic (LD50: 14518.0 μg/ml). Anethole and Cymbopogon oil had the highest selectivity ratios. The expression of AChE, a gene that regulates the production of acetyl cholinesterase, a detoxifying enzyme, was not altered in bees treated with the plant compounds at 48 h post-treatment. This study showed that anethole and Cymbopogon oil have potential for controlling Varroa mites and seem to be relatively safe for larvae and adult honey bees.

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Unraveling Honey Bee–Varroa destructor Interaction: Multiple Factors Involved in Differential Resistance between Two Uruguayan Populations

Veterinary Sciences ◽

10.3390/vetsci7030116 ◽

2020 ◽

Vol 7 (3) ◽

pp. 116

Author(s):

Yamandú Mendoza ◽

Ivanna H. Tomasco ◽

Karina Antúnez ◽

Loreley Castelli ◽

Belén Branchiccela ◽

...

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Differential Resistance ◽

Natural Resistance ◽

Significant Genetic Differentiation ◽

Deformed Wing Virus ◽

Relevant Role ◽

Behavioral Resistance ◽

Short Tandem

The ectoparasite Varroa destructor is the greatest biotic threat of honey bees Apis mellifera in vast regions of the world. Recently, the study of natural mite-resistant populations has gained much interest to understand the action of natural selection on the mechanisms that limit the mite population. In this study, the components of the A. mellifera–V. destructor relationship were thoroughly examined and compared in resistant and susceptible honey bee populations from two regions of Uruguay. Mite-resistant honey bees have greater behavioral resistance (hygienic and grooming behaviors) than susceptible honey bees. At the end of the summer, resistant honey bees had fewer mites and a lower deformed wing virus (DWV) viral load than susceptible honey bees. DWV variant A was the only detected variant in honey bees and mites. Molecular analysis by Short Tandem Repeat showed that resistant honey bees were Africanized (A. m. scutellata hybrids), whereas susceptible honey bees were closer to European subspecies. Furthermore, significant genetic differentiation was also found between the mite populations. The obtained results show that the natural resistance of honey bees to V. destructor in Uruguay depends on several factors and that the genetic variants of both organisms can play a relevant role.

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Genome Sequences of Two Single-Stranded DNA Viruses Identified in Varroa destructor

Genome Announcements ◽

10.1128/genomea.00107-18 ◽

2018 ◽

Vol 6 (9) ◽

Cited By ~ 3

Author(s):

Simona Kraberger ◽

Gabriel A. Visnovsky ◽

Ron F. van Toor ◽

Maketalena F. Male ◽

Kara Waits ◽

...

Keyword(s):

New Zealand ◽

Honey Bee ◽

Honey Bees ◽

Varroa Destructor ◽

Genome Sequences ◽

Single Stranded Dna ◽

Dna Viruses ◽

Content Type ◽

Pathogenic Viruses ◽

Parasitic Mite

ABSTRACT Varroa destructor is a ubiquitous and parasitic mite of honey bees, infecting them with pathogenic viruses having a major impact on apiculture. We identified two novel circular replication-associated protein (Rep)-encoding single-stranded (CRESS) DNA viruses from V. destructor sampled from a honey bee hive near Christchurch in New Zealand.

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

Experimental and Applied Acarology ◽

10.1007/s10493-020-00562-7 ◽

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.

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