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Fanny Mondet - One of the best experts on this subject based on the ideXlab platform.
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Chemical detection triggers honey bee defense against a destructive parasitic threat
Nature Chemical Biology, 2021Co-Authors: Fanny Mondet, Solene Blanchard, Nicolas Barthes, Dominique Beslay, Celia Bordier, Guy Costagliola, Maxime R. Hervé, Benoit Lapeyre, Seo Hyun Kim, Benjamin BassoAbstract:Invasive species events related to globalization are increasing, resulting in parasitic outbreaks. Understanding of host defense mechanisms is needed to predict and mitigate against the consequences of parasite invasion. Using the honey bee Apis mellifera and the mite Varroa destructor , as a host–parasite model, we provide a comprehensive study of a mechanism of parasite detection that triggers a behavioral defense associated with social immunity. Six Varroa -parasitization-specific (VPS) compounds are identified that (1) trigger Varroa -sensitive hygiene (VSH, bees’ key defense against Varroa sp.), (2) enable the selective recognition of a parasitized brood and (3) induce responses that mimic intrinsic VSH activity in bee colonies. We also show that individuals engaged in VSH exhibit a unique ability to discriminate VPS compounds from healthy brood signals. These findings enhance our understanding of a critical mechanism of host defense against parasites, and have the potential to apply the integration of pest management in the beekeeping sector. In honey bee colonies infested with the mite Varroa destructor , six Varroa -parasitization-specific (VPS) compounds trigger protective behavior in the bees, which are able to distinguish VPS compounds from healthy signals and recognize an infested brood.
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Varroa destructor: A Complex Parasite, Crippling Honey Bees Worldwide.
Trends in parasitology, 2020Co-Authors: Kirsten S. Traynor, Panuwan Chantawannakul, Fanny Mondet, Joachim R De Miranda, Maéva Angélique Techer, Vienna Kowallik, Melissa A. Y. Oddie, Alison McafeeAbstract:The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honey bee (Apis cerana), to the naive European honey bee (Apis mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honey bee health. Worrying observations include increasing acaricide resistance in the Varroa population and sinking economic treatment thresholds, suggesting that the mites or their vectored viruses are becoming more virulent. Highly infested weak colonies facilitate mite dispersal and disease transmission to stronger and healthier colonies. Here, we review recent developments in the biology, pathology, and management of Varroa, and integrate older knowledge that is less well known.
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Varroa destructor: A Complex Parasite, Crippling Honeybees Worldwide
2020Co-Authors: Kirsten Traynor, Panuwan Chantawannakul, Fanny Mondet, Maéva Angélique Techer, Vienna Kowallik, Melissa A. Y. Oddie, Jaochim De Miranda, Alison McafeeAbstract:The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honeybee (Apis cerana), to the naïve European honeybee (A. mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honeybee health. Worrying observations include increasing acaricide resistance in the Varroa population and sinking economic treatment thresholds, suggesting that the mites or their vectored viruses are becoming more virulent. Highly infested weak colonies, popularly dubbed “mite bombs”, facilitate mite dispersal and disease transmission to stronger and healthier colonies. Here, we review recent developments in the biology, pathology and management of Varroa, and unearth old knowledge that was lost in the archives.
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Seasonal variations influencing Varroa Sensitive Hygiene trait in the honey bee
2019Co-Authors: Léa Tison, Yves Le Conte, Andre Kretzschmar, Alban Maisonnasse, Clemence Riva, Pascal Jourdan, Fanny MondetAbstract:Varroa resistance can be defined as the ability of honey bee colonies to survive the parasite for several years in the absence of any treatment against the mite. Long-term survival of untreated Apis mellifera populations has been reported in the US and Europe. The ability of honey bee colonies to survive Varroa mite infestations has been associated with the development of Varroa Sensitive Hygiene behavior (VSH). Resistant colonies are able to detect the presence of Varroa through the cap of developing brood cells and to remove parasitized brood and the mites. To improve breeding programs for Varroa resistance, detailed knowledge of the mechanisms that enable bees to survive mite infestation and environmental conditions that can influence the expression and evaluation of VSH behavior are needed. This study aims at evaluating the influence of the coloniy population dynamics, the Varroa density in colonies, he task allocation strategy and the food supply on the ability of colonies to expres the VSH trait. Such efforts are particularly important to standardize testing in different locations, a feature that is essential to ensure the success of breeding efforts.
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on the front line quantitative virus dynamics in honeybee apis mellifera l colonies along a new expansion front of the parasite Varroa destructor
PLOS Pathogens, 2014Co-Authors: Fanny Mondet, Joachim R De Miranda, Andre Kretzschmar, Yves Le Conte, Alison R MercerAbstract:Over the past fifty years, annual honeybee (Apis mellifera) colony losses have been steadily increasing worldwide. These losses have occurred in parallel with the global spread of the honeybee parasite Varroa destructor. Indeed, Varroa mite infestations are considered to be a key explanatory factor for the widespread increase in annual honeybee colony mortality. The host-parasite relationship between honeybees and Varroa is complicated by the mite's close association with a range of honeybee viral pathogens. The 10-year history of the expanding front of Varroa infestation in New Zealand offered a rare opportunity to assess the dynamic quantitative and qualitative changes in honeybee viral landscapes in response to the arrival, spread and level of Varroa infestation. We studied the impact of de novo infestation of bee colonies by Varroa on the prevalence and titres of seven well-characterised honeybee viruses in both bees and mites, using a large-scale molecular ecology approach. We also examined the effect of the number of years since Varroa arrival on honeybee and mite viral titres. The dynamic shifts in the viral titres of black queen cell virus and Kashmir bee virus mirrored the patterns of change in Varroa infestation rates along the Varroa expansion front. The deformed wing virus (DWV) titres in bees continued to increase with Varroa infestation history, despite dropping infestation rates, which could be linked to increasing DWV titres in the mites. This suggests that the DWV titres in mites, perhaps boosted by virus replication, may be a major factor in maintaining the DWV epidemic after initial establishment. Both positive and negative associations were identified for several pairs of viruses, in response to the arrival of Varroa. These findings provide important new insights into the role of the parasitic mite Varroa destructor in influencing the viral landscape that affects honeybee colonies.
James D. Ellis - One of the best experts on this subject based on the ideXlab platform.
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Comparing four methods of rearing Varroa destructor in vitro.
Experimental & applied acarology, 2020Co-Authors: Cameron J. Jack, Pingli Dai, Edzard Van Santen, James D. EllisAbstract:The parasitic mite Varroa destructor Anderson and Trueman continues to devastate western honey bee (Apis mellifera L.) colonies throughout most of the world where they are managed. The development of a method to rear Varroa in vitro would allow for year-round Varroa research, rapidly advancing our progress towards controlling the mite. We created two separate experiments to address this objective. First, we determined which of four in vitro rearing methods yields the greatest number of Varroa offspring. Second, we attempted to improve the rearing rates achieved with that method. The four methods tested included (1) rearing Varroa on honey bee pupae in gelatin capsules, (2) rearing Varroa on in vitro-reared honey bees, (3) group rearing Varroa on honey bee pupae in Petri dishes, and (4) providing Varroa a bee-derived diet. The number of reproducing females and the number of fully mature offspring were significantly higher in the gelatin capsules maintained at 75% RH than in any other method. A 2 × 3 full factorial design was used to test combinations of gelatin capsule size (6 and 7 mm diameter) and relative humidity (65, 75, or 85%) on Varroa rearing success. Varroa reproduction and survival were significantly higher in 7-mm-diameter gelatin capsules maintained at 75% RH than in those maintained in 6-mm capsules and at the other humidities. By identifying factors that influence Varroa reproductive success in vitro, this work provides an important foundation for the development of future rearing protocols.
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The discovery of Varroa destructor on drone honey bees, Apis mellifera, at drone congregation areas.
Parasitology research, 2018Co-Authors: Ashley N Mortensen, Cameron J. Jack, James D. EllisAbstract:Varroa is an external parasitic mite of honey bees and is a vector of multiple viruses that can severely weaken or cause the failure of western honey bee colonies if untreated. Effective Varroa control is dependent upon a thorough understanding of Varroa biology, including how Varroa move between host colonies. Here, we highlight that drone (male) honey bees may also play a role in Varroa dispersal. Drones were collected and the number of Varroa per 100 drones was calculated for each of five drone congregation areas (mating sites). This study is the first to confirm that drones present at drone congregation areas do carry Varroa. Further experimentation is needed to determine the extent to which drone-mediated movement may play a role in Varroa life history and/or to develop practical management strategies to limit drone-mediated movement of Varroa between honey bee hives.
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erratum to differences in Varroa destructor infestation rates of two indigenous subspecies of apis mellifera in the republic of south africa
Experimental and Applied Acarology, 2016Co-Authors: Ashley N Mortensen, Daniel R Schmehl, Mike Allsopp, Tomas A Bustamante, Chase B Kimmel, Mark E Dykes, James D. EllisAbstract:Varroa destructor Anderson & Trueman (Varroa) is a damaging pest of the Western honey bee, Apis mellifera, in North America, Europe, and Asia. However, Varroa infestations have not produced equivalent colony losses of African subspecies of honey bee throughout Africa and parts of the Americas. We surveyed the Varroa infestation rates (number of Varroa per 100 adult honey bees) in colonies of A. m. scutellata, A. m. capensis, and hybrids of the two subspecies throughout the Republic of South Africa in the fall of 2014. We found that A. m. scutellata colonies had significantly higher Varroa infestations than did A. m. capensis colonies. Furthermore, hybridized colonies of the two subspecies had Varroa infestations intermediate to those of A. m. scutellata and A. m. capensis. This is the first documentation of a clear difference in Varroa infestation rates of A. m. scutellata, A. m. capensis, and hybridized colonies in South Africa. Furthermore, our data confirm that Varroa populations in A. m. scutellata colonies are within the range of populations that are damaging to European honey bees.
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the efficacy of dusting honey bee colonies with powdered sugar to reduce Varroa mite populations
Journal of Apicultural Research, 2009Co-Authors: Amanda M Ellis, Gerry W Hayes, James D. EllisAbstract:SummaryControlling Varroa mite (Varroa destructor Anderson and Trueman) populations in honey bee (Apis mellifera L.) colonies with acaricides has been a challenge for beekeepers due to the rapid development of resistant mite populations. For this reason, many beekeepers are adopting Integrated Pest Management strategies as alternatives to chemocentric Varroa control schemes. One non-chemical tool that has been used for Varroa control is dusting bee colonies with powdered sugar. The objective of our study was to determine the efficacy of powdered sugar as a Varroa control by comparing mite populations, adult bee populations, and brood area in untreated colonies with those in colonies dusted every two weeks for 11 months with 120 g powdered sugar per application. We found that dusting colonies with powdered sugar did not significantly affect the adult bee population (treated: 10061.72 ± 629.42; control: 10691.00 ± 554.44) or amount of brood (treated: 4521.91 ± 342.84 cm2; control: 4472.55 ± 365.85 cm2). We ...
Tjeerd Blacquière - One of the best experts on this subject based on the ideXlab platform.
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Varroa sensitive hygiene contributes to naturally selected Varroa resistance in honey bees
Journal of Apicultural Research, 2017Co-Authors: Delphine Panziera, Frank Van Langevelde, Tjeerd BlacquièreAbstract:The parasitic mite Varroa destructor is a serious threat for western honey bee colonies and beekeepers are compelled to control it to keep their colonies healthy. Yet, by controlling Varroa no resistance to the parasite can evolve. As a trial, honey bee colonies have been left untreated in isolated locations to allow development of resistance or tolerance to the mite. These colonies developed an ability to live without control measures against Varroa, although the traits responsible for this resistance or tolerance are still unclear. Two of these resistant populations have been studied to test the involvement of specific Varroa mite targeted hygienic behaviour Varroa sensitive hygiene (VSH) in the acquired resistance. Individual mites were manually introduced into just capped brood cells, after which the brood combs were placed in colonies of the two resistant populations and in control colonies in which Varroa had always been controlled. We followed the development of the mites, including possible remova...
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Effectieve bestrijding van Varroa (Tweede, licht gewijzigde druk)
2013Co-Authors: B. Cornelissen, Tjeerd Blacquière, J.j.m. Van Der SteenAbstract:De Varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze tweede, licht gewijzigde druk biedt informatie over de biologie van Varroa, de effecten van Varroa op honingbijen en de bestrijding van Varroa.
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Effectieve bestrijding van Varroa
2010Co-Authors: B. Cornelissen, Tjeerd Blacquière, J.j.m. Van Der SteenAbstract:De Varroa mijtziekte (Varroa destructor) is de belangrijkste bedreiging van de Europese honingbij. Wintersterfte van honingbijen is in de meeste gevallen toe te schrijven aan deze ziekte. Deze brochure van de WUR biedt informatie over de biologie van Varroa, de effecten van Varroa op honingbijen en de bestrijding van Varroa.
Frank Van Langevelde - One of the best experts on this subject based on the ideXlab platform.
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Varroa destructor infestation impairs the improvement of landing performance in foraging honeybees
Royal Society open science, 2020Co-Authors: Florian T. Muijres, Coby Van Dooremalen, Martin J.m. Lankheet, Heleen Lugt, Lana J. De Vries, Frank Van LangeveldeAbstract:The parasitic mite Varroa destructor is an important contributor to the high losses of western honeybees. Forager bees from Varroa-infested colonies show reduced homing and flight capacity; it is not known whether flight manoeuvrability and related learning capability are also affected. Here, we test how honeybees from Varroa-infested and control colonies fly in an environment that is unfamiliar at the beginning of each experimental day. Using stereoscopic high-speed videography, we analysed 555 landing manoeuvres recorded during 12 days of approximately 5 h in length. From this, we quantified landing success as percentage of successful landings, and assessed how this changed over time. We found that the forager workforce of Varroa-infested colonies did not improve their landing success over time, while for control bees landing success improved with approximately 10% each hour. Analysis of the landing trajectories showed that control bees improved landing success by increasing the ratio between in-flight aerodynamic braking and braking at impact on the landing platform; bees from Varroa-infested colonies did not increase this ratio over time. The Varroa-induced detriment to this landing skill-learning capability might limit forager bees from Varroa-infested colonies to adapt to new or challenging conditions; this might consequently contribute to Varroa-induced mortality of honeybee colonies.
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Varroa sensitive hygiene contributes to naturally selected Varroa resistance in honey bees
Journal of Apicultural Research, 2017Co-Authors: Delphine Panziera, Frank Van Langevelde, Tjeerd BlacquièreAbstract:The parasitic mite Varroa destructor is a serious threat for western honey bee colonies and beekeepers are compelled to control it to keep their colonies healthy. Yet, by controlling Varroa no resistance to the parasite can evolve. As a trial, honey bee colonies have been left untreated in isolated locations to allow development of resistance or tolerance to the mite. These colonies developed an ability to live without control measures against Varroa, although the traits responsible for this resistance or tolerance are still unclear. Two of these resistant populations have been studied to test the involvement of specific Varroa mite targeted hygienic behaviour Varroa sensitive hygiene (VSH) in the acquired resistance. Individual mites were manually introduced into just capped brood cells, after which the brood combs were placed in colonies of the two resistant populations and in control colonies in which Varroa had always been controlled. We followed the development of the mites, including possible remova...
Yves Le Conte - One of the best experts on this subject based on the ideXlab platform.
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Seasonal variations influencing Varroa Sensitive Hygiene trait in the honey bee
2019Co-Authors: Léa Tison, Yves Le Conte, Andre Kretzschmar, Alban Maisonnasse, Clemence Riva, Pascal Jourdan, Fanny MondetAbstract:Varroa resistance can be defined as the ability of honey bee colonies to survive the parasite for several years in the absence of any treatment against the mite. Long-term survival of untreated Apis mellifera populations has been reported in the US and Europe. The ability of honey bee colonies to survive Varroa mite infestations has been associated with the development of Varroa Sensitive Hygiene behavior (VSH). Resistant colonies are able to detect the presence of Varroa through the cap of developing brood cells and to remove parasitized brood and the mites. To improve breeding programs for Varroa resistance, detailed knowledge of the mechanisms that enable bees to survive mite infestation and environmental conditions that can influence the expression and evaluation of VSH behavior are needed. This study aims at evaluating the influence of the coloniy population dynamics, the Varroa density in colonies, he task allocation strategy and the food supply on the ability of colonies to expres the VSH trait. Such efforts are particularly important to standardize testing in different locations, a feature that is essential to ensure the success of breeding efforts.
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Differential gene expression of the honey bee Apis mellifera associated with Varroa destructor infection
BMC Genomics, 2008Co-Authors: Maria Navajas, Didier Crauser, Alain Migeon, C. Alaux, Marie-laure Martin-magniette, G.e. Robinson, J.d. Evans, Sandrine Cros-arteil, Yves Le ConteAbstract:Background: The parasitic mite, Varroa destructor, is the most serious pest of the western honey bee, Apis mellifera, and has caused the death of millions of colonies worldwide. This mite reproduces in brood cells and parasitizes immature and adult bees. We investigated whether Varroa infestation induces changes in Apis mellifera gene expression, and whether there are genotypic differences that affect gene expression relevant to the bee's tolerance, as first steps toward unravelling mechanisms of host response and differences in susceptibility to Varroa parasitism. Results: We explored the transcriptional response to mite parasitism in two genetic stocks of A. mellifera which differ in susceptibility to Varroa, comparing parasitized and non-parasitized full-sister pupae from both stocks. Bee expression profiles were analyzed using microarrays derived from honey bee ESTs whose annotation has recently been enhanced by results from the honey bee genome sequence. We measured differences in gene expression in two colonies of Varroa-susceptible and two colonies of Varroa-tolerant bees. We identified a set of 148 genes with significantly different patterns of expression: 32 varied with the presence of Varroa, 116 varied with bee genotype, and 2 with both. Varroa parasitism caused changes in the expression of genes related to embryonic development, cell metabolism and immunity. Bees tolerant to Varroa were mainly characterized by differences in the expression of genes regulating neuronal development, neuronal sensitivity and olfaction. Differences in olfaction and sensitivity to stimuli are two parameters that could, at least in part, account for bee tolerance to Varroa; differences in olfaction may be related to increased grooming and hygienic behavior, important behaviors known to be involved in Varroa tolerance. Conclusion: These results suggest that differences in behavior, rather than in the immune system, underlie Varroa tolerance in honey bees, and give an indication of the specific physiological changes found in parasitized bees. They provide a first step toward better understanding molecular pathways involved in this important host-parasite relationship
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Essai d’efficacité thérapeutique de l’amitraze contre Varroa destructor
Abeille de France et l'Apiculteur, 2007Co-Authors: Yves Le Conte, Didier Crauser, Jean-marc BecardAbstract:De nombreux exemples montrent qu’à terme les acariens deviennent résistants aux acaricides utilisés pour contrôler leurs populations. L’amitraze est utilisée depuis plus de 23 ans pour lutter contre le Varroa et il se pose régulièrement la question de l’apparition de populations résistantes. Cet article traite de l’efficacité de cette molécule sur des populations de Varroas en Avignon.
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Signature et camouflage chimique du Varroa chez Apis cerana et A. mellifera: un phénomène adaptatif et coévolutif
2006Co-Authors: Anne-geneviève Bagnères, Yves Le Conte, Zachary Huang, Maria Navajas Navarro, M. Salvy., Jean Phillipe Christides, . Union Internationale Pour L'etude Des Insectes SocAbstract:L’acarien Varroa destructor est un ectoparasite dont l’hôte d’origine asiatique est Apis cerana, mais est devenu un danger pour A. mellifera en Europe et dans le reste du monde. En outre, nous avons montré, à l'aide d'une analyse du polymorphisme mitochondrial, que les Varroas prélevés sur les colonies cerana constituaient un haplotype différent de ceux qui parasitent mellifera, et cela, bien que les colonies des deux espèces abeilles cohabitent dans un même endroit. Le contact entre la fondatrice de Varroa et la larve de 5ème stade d’Apis avant l’operculation de l'alvéole est important car il déclenche la reproduction de l’acarien. Sa descendance viendra en effet à son tour se nourrir de la nymphe. La reproduction haplodiploïde de l’acarien donnera successivement des mâles haploïdes puis des femelles diploïdes, en passant par le stade de larve, puis de protonymphe, puis de deutonymphe, avant de parvenir au stade adulte. La signature chimique des différents stades a été étudiée et a montré un dimorphisme sexuel important. Le mimétisme chimique de l'acarien est un caractère adaptatif important compte tenu des capacités très développées de reconnaissance du parasite par son hôte d'origine, A. cerana, capacités très réduites chez son nouvel hôte A. mellifera. Afin d'étudier les bases de ce mimétisme chimique, il a été procédé à une expérience de transfert : des acariens provenant de cerana sont transférés soit à nouveau sur du couvain cerana, soit sur du couvain mellifera ; inversement, des parasites de mellifera sont transférés soit à nouveau sur du couvain mellifera, soit sur du couvain cerana. Les signatures chimiques à la fois des nymphes de Apis et leurs Varroas ont été étudiées dans les 4 situations. On s’aperçoit que les parasites vont en priorité mimer chimiquement l’hôte sur lequel ils sont placés, quelque soit leur mitotype, par contre le camouflage du Varroa originaire de cerana parait plus performant. Les deux haplotypes possèdent donc une capacité de mimétisme étonnante qui dépend de la pression évolutive due à l’hôte.
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Essai d'efficacité thérapeutique de l'amitraze contre "Varroa destructor
Abeilles et Fleurs, 2006Co-Authors: Yves Le Conte, Didier CrauserAbstract:De nombreux exemples montrent qu’à terme les acariens deviennent résistants aux acaricides utilisés pour contrôler leurs populations. L’amitraze est utilisée depuis plus de 23 ans pour lutter contre le Varroa et il se pose régulièrement la question de l’apparition de populations résistantes. Cet article traite de l’efficacité de cette molécule sur des populations de Varroas en Avignon.
