Understanding the impact of agri-environment schemes on emerging infectious diseases in pollinators

埃博拉病毒在西非的毁灭性传播是最近许多直接影响人类健康的新兴疾病之一。然而，在管理和野生动物中出现的新疾病也可能间接影响人类健康和粮食安全。例如，一种寄生蠕虫(名为Varroa destructor)及其传播的病毒在全球范围内在蜜蜂中传播，导致野生蜜蜂种群灭绝，并导致欧洲和北美受管理的蜂箱数量大幅下降。由于蜜蜂对农作物授粉和生产蜂蜜很重要，这种损失可能会对农业系统的可持续性产生重大影响，因此，通过粮食产量的下降，人类健康。授粉--授粉--花受精以产生种子和果实--在农业和自然环境中都是一个关键过程。虽然蜜蜂是重要的传粉者，但野生蜜蜂，如大黄蜂，对农作物和野花都同样重要，如果不是更重要的话。因此，蜜蜂和野生蜜蜂在全球大部分地区都在减少的事实是一个主要的担忧。早期大黄蜂和其他野生蜜蜂数量的下降似乎是由于失去了合适的栖息地，包括生存所需的花朵、筑巢地点和冬眠地点。然而，最近，北美和南美大黄蜂数量的大幅下降似乎与新出现的病原体的传播有关。因此，导致蜜蜂衰退的病毒在野生大黄蜂身上也存在，这一发现令人深感担忧。英国最近的研究表明，像变形翅膀病毒这样的有害病毒正在受管理的蜜蜂和野生熊蜂之间来回传播。种植花蜜和产生花粉的花条可能会加剧这种传播，这是农民试图增加野生传粉者数量以进行作物授粉的主要方式之一。然而，我们目前不知道这些病毒的主要传播方向--是从蜜蜂传播到大黄蜂，还是从蜜蜂传播到熊蜂？也不知道野花带是否会改变传播的速度和方向，或者传播过程背后的实际机制。如果我们要在我们的基本管理和野生蜜蜂中管理新出现的病毒疾病，这些是我们需要解决的问题。在我们的工作中，我们建议结合现实世界和实验室研究来回答这些问题。首先，我们将从有野花带和没有野花带地区的农场采集蜜蜂样本，并对它们进行病毒筛查。我们将使用新的基因组测序技术，结合复杂的统计模型，来确定病毒是否主要从蜜蜂传播到大黄蜂，或者反之亦然，以及野花带的存在是否增强了传播或改变了传播方向。与此相结合，我们将在实验室进行受控实验，以确定花的类型和病毒颗粒在花上的时间长度如何影响访花蜜蜂感染的可能性。这将有助于我们理解蜜蜂之间传播的细微机制。最后，我们将在多个隧道中对整个蜂箱进行大型实验，以测试花的密度、花的类型和蜜蜂的密度如何决定病毒的传播率。总之，这些实验室和半野外(多隧道)实验将帮助我们从项目的第一部分了解在野生蜜蜂中发现的传播模式。最终，我们将利用这些结果，就如何减少新出现的病毒在我们的野生和受管理的蜜蜂之间的传播提出建议，从而增加它们的种群，同时最大限度地为英国的农作物和野花授粉。

The devastating spread of the Ebola virus in West Africa is one of many recent examples of emerging diseases that directly impact human health. However, emerging diseases in managed and wild animals may also indirectly affect human health and food security. For example, the global spread of a parasitic mite (called Varroa destructor), and the viruses it transmits, in honeybees has wiped out wild honeybee populations, and driven large declines in the number of managed hives in Europe and North America. As honeybees are important for pollinating crops and producing honey, such losses could have significant impacts on the sustainability of agricultural systems and, thus, through declines in food production, human health.Pollination - the fertilization of flowers to produce seeds and fruit - is a key process in both agricultural and natural environments. While honeybees are important pollinators, wild bees, such as bumblebees, are just as, if not more important for both crops and wildflowers. Consequently, the fact that both honeybees and wild bees are in decline across much of the globe is a major concern. Earlier declines in bumblebees and other wild bees appeared to be driven by the loss of suitable habitat, containing the flowers, nesting sites, and hibernation sites needed for survival. However, recently, major declines in bumblebees in North and South America appear to be related to the spread of emerging pathogens. Thus, the discovery that the viruses driving declines in honeybees are also present in wild bumblebees is deeply worrying. Recent research in the UK has shown that harmful viruses like Deformed Wing Virus are being transmitted to-and-fro between managed honeybees and wild bumblebees. Such transmission may be exacerbated by the planting of nectar and pollen-producing flower strips, one of the major ways farmers try to enhance the populations of wild pollinators for crop pollination. However, we currently do not know the major direction of spread for these viruses - is it from honeybees to bumblebees, or vice versa? - and whether wild-flower strips change the rate and direction of transmission, or the actual mechanics behind how transmission occurs. If we are to manage emerging viral diseases in our essential managed and wild bees, these are the questions we need to address.In our work, we propose to combine real-world and laboratory studies to answer these questions. First, we will sample bees from farms in areas with and without wild-flower strips, and screen them for viruses. We will use new genome sequencing technology, combined with complex statistical models, to determine whether viruses spread predominantly from honeybees to bumblebees, or vice versa, and whether the presence of wild-flower strips enhances transmission or changes its direction. In combination with this, we will conduct controlled experiments in the laboratory to determine how the type of flower and the length of time viral particles are on flowers, affect the likelihood of a flower-visiting bee becoming infected. This will help us to understand the fine-scale mechanisms by which transmission among bees takes place. Finally, we will conduct large experiments with whole hives of bees in polytunnels to test how the density of flowers, type of flowers, and density of bees determine the rate of viral spread. Together, these laboratory and semi-field (polytunnel) experiments will help us to understand the patterns of transmission found in wild bees from the first part of the project. Ultimately, we will use these results to make recommendations on how to reduce the transmission of emerging viruses among our wild and managed bees, and thus enhance their populations while maximising pollination of both crops and wildflowers in the UK landscape