Department of Agro-Ecology, Rothamsted Research, Harpenden, Hertfordshire, United Kingdom; School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.
School of Biological Sciences, Queen's University Belfast, Belfast, Northern Ireland, United Kingdom; Institute for Biology, Martin-Luther-Universität Halle-Wittenberg, Halle/Saale, Germany.
PLoS One. 2014 Aug 6;9(8):e103989. doi: 10.1371/journal.pone.0103989. eCollection 2014.
Pathogens may gain a fitness advantage through manipulation of the behaviour of their hosts. Likewise, host behavioural changes can be a defence mechanism, counteracting the impact of pathogens on host fitness. We apply harmonic radar technology to characterize the impact of an emerging pathogen--Nosema ceranae (Microsporidia)--on honeybee (Apis mellifera) flight and orientation performance in the field. Honeybees are the most important commercial pollinators. Emerging diseases have been proposed to play a prominent role in colony decline, partly through sub-lethal behavioural manipulation of their hosts. We found that homing success was significantly reduced in diseased (65.8%) versus healthy foragers (92.5%). Although lost bees had significantly reduced continuous flight times and prolonged resting times, other flight characteristics and navigational abilities showed no significant difference between infected and non-infected bees. Our results suggest that infected bees express normal flight characteristics but are constrained in their homing ability, potentially compromising the colony by reducing its resource inputs, but also counteracting the intra-colony spread of infection. We provide the first high-resolution analysis of sub-lethal effects of an emerging disease on insect flight behaviour. The potential causes and the implications for both host and parasite are discussed.
病原体可能通过操纵宿主的行为获得适应性优势。同样，宿主行为的改变也可以是一种防御机制，抵消病原体对宿主适应性的影响。我们应用谐波雷达技术来描述一种新兴病原体——蜜蜂微孢子虫（Nosema ceranae）（微孢子虫）对野外蜜蜂（Apis mellifera）飞行和定向性能的影响。蜜蜂是最重要的商业授粉昆虫。新兴疾病被认为在蜂群减少中起重要作用，部分原因是通过对宿主的亚致死行为操纵。我们发现，患病（65.8%）的归巢蜂比健康的觅食蜂（92.5%）的归巢成功率显著降低。尽管迷失的蜜蜂持续飞行时间明显缩短，休息时间延长，但感染蜂和非感染蜂的其他飞行特征和导航能力没有显著差异。我们的研究结果表明，感染的蜜蜂表现出正常的飞行特征，但在归巢能力上受到限制，这可能通过减少其资源输入来削弱蜂群，同时也抵消了感染在蜂群内部的传播。我们首次对一种新兴疾病对昆虫飞行行为的亚致死影响进行了高分辨率分析。讨论了潜在的原因及其对宿主和寄生虫的影响。
