Wells Trish, Wolf Stephan, Nicholls Elizabeth, Groll Helga, Lim Ka S, Clark Suzanne J, Swain Jennifer, Osborne Juliet L, Haughton Alison J
Rothamsted Research, Harpenden, UK.
Environ Microbiol Rep. 2016 Oct;8(5):728-737. doi: 10.1111/1758-2229.12434. Epub 2016 Jul 7.
Sudden and severe declines in honey bee (Apis mellifera) colony health in the US and Europe have been attributed, in part, to emergent microbial pathogens, however, the mechanisms behind the impact are unclear. Using roundabout flight mills, we measured the flight distance and duration of actively foraging, healthy-looking honey bees sampled from standard colonies, before quantifying the level of infection by Nosema ceranae and Deformed Wing Virus complex (DWV) for each bee. Neither the presence nor the quantity of N. ceranae were at low, natural levels of infection had any effect on flight distance or duration, but presence of DWV reduced flight distance by two thirds and duration by one half. Quantity of DWV was shown to have a significant, but weakly positive relation with flight distance and duration, however, the low amount of variation that was accounted for suggests further investigation by dose-response assays is required. We conclude that widespread, naturally occurring levels of infection by DWV weaken the flight ability of honey bees and high levels of within-colony prevalence are likely to reduce efficiency and increase the cost of resource acquisition. Predictions of implications of pathogens on colony health and function should take account of sublethal effects on flight performance.
美国和欧洲蜜蜂（西方蜜蜂）蜂群健康的突然严重下降，部分归因于新出现的微生物病原体，然而，其影响背后的机制尚不清楚。我们使用环形飞行磨，测量了从标准蜂群中采集的外观健康、正在积极觅食的蜜蜂的飞行距离和持续时间，然后对每只蜜蜂的微孢子虫和变形翅病毒复合体（DWV）感染水平进行量化。微孢子虫的存在与否及其数量处于低自然感染水平时，对飞行距离或持续时间均无任何影响，但DWV的存在使飞行距离减少了三分之二，持续时间减少了一半。DWV的数量与飞行距离和持续时间呈显著但微弱的正相关关系，然而，所解释的低变异量表明需要通过剂量反应试验进行进一步研究。我们得出结论，DWV广泛的自然感染水平会削弱蜜蜂的飞行能力，而蜂群内的高流行水平可能会降低效率并增加资源获取成本。病原体对蜂群健康和功能影响的预测应考虑对飞行性能的亚致死效应。
