Honey bee colony winter loss rates for 35 countries participating in the COLOSS survey for winter 2018–2019, and the effects of a new queen on the risk of colony winter loss.
Date
2020-08-11
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Publisher
Taylor & Francis, International Bee Research Association
Abstract
This article presents managed honey bee colony loss rates over winter 2018/19 resulting from using the standardised
COLOSS questionnaire in 35 countries (31 in Europe). In total, 28,629 beekeepers supplying valid loss data wintered
738,233 colonies, and reported 29,912 (4.1%, 95% confidence interval (CI) 4.0–4.1%) colonies with unsolvable queen
problems, 79,146 (10.7%, 95% CI 10.5–10.9%) dead colonies after winter and 13,895 colonies (1.9%, 95% CI 1.8–2.0%)
lost through natural disaster. This gave an overall colony winter loss rate of 16.7% (95% CI 16.4–16.9%), varying greatly
between countries, from 5.8% to 32.0%. We modelled the risk of loss as a dead/empty colony or from unresolvable
queen problems, and found that, overall, larger beekeeping operations with more than 150 colonies experienced significantly lower losses (p < 0.001), consistent with earlier studies. Additionally, beekeepers included in this survey who did
not migrate their colonies at least once in 2018 had significantly lower losses than those migrating (p < 0.001). The percentage of new queens from 2018 in wintered colonies was also examined as a potential risk factor. The percentage of
colonies going into winter with a new queen was estimated as 55.0% over all countries. Higher percentages of young
queens corresponded to lower overall losses (excluding losses from natural disaster), but also lower losses from unresolvable queen problems, and lower losses from winter mortality (p < 0.001). Detailed results for each country and
overall are given in a table, and a map shows relative risks of winter loss at regional level.
Description
Publication history: Accepted - 14 July 2020; Published Online - 11 August 2020
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Article
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Keywords
Apis mellifera, mortality, colony winter losses, queens, queen replacement, monitoring surveys, beekeeping, citizen science
Citation
Gray, A., Adjlane, N., Arab, A., Ballis, A., Brusbardis, V., Charrière, J.-D., Chlebo, R., Coffey, M. F., Cornelissen, B., Amaro da Costa, C., Dahle, B., Danihlík, J., Dražić, M. M., Evans, G., Fedoriak, M., Forsythe, I., Gajda, A., de Graaf, D. C., Gregorc, A., Ilieva, I., Johannesen, J., Kauko, L., Kristiansen, P., Martikkala, M., Martín-Hernández, R., Medina-Flores, C. A., Mutinelli, F., Patalano, S., Raudmets, A., Martin, G. S., Soroker, V., Stevanovic, J., Uzunov, A., Vejsnaes, F., Williams, A., Zammit-Mangion, M. and Brodschneider, R. (2020) ‘Honey bee colony winter loss rates for 35 countries participating in the COLOSS survey for winter 2018–2019, and the effects of a new queen on the risk of colony winter loss’, Journal of Apicultural Research. Informa UK Limited, pp. 1–8. doi: 10.1080/00218839.2020.1797272.