Impact and mitigation of emergent diseases on major UK insect pollinators

2005/06年冬季，美国数千个蜜蜂群落神秘死亡，被称为“蜂群衰竭失调症”，这一事件将媒体的注意力集中在蜜蜂的困境上，蜜蜂是世界上主要的传粉者。在英国，蜜蜂和24种大黄蜂在农作物和野花授粉中发挥着重要作用，但它们的数量都在严重下降。外来（非本地）和新出现的（本地，但毒性增加）疾病被认为是蜜蜂数量下降的主要原因，因此它们是英国蜜蜂面临的最大挑战之一。这种单细胞微孢子菌“真菌”是蜜蜂的一种外来传染病，主要攻击蜜蜂的肠道。我们已经证明，在过去的大约10年里，它已经在世界范围内传播，包括英国，它与美国（2005/06）和西班牙（2007/08）的蜜蜂群崩溃有关。畸形翼病毒（DWV）是与蜜蜂瓦螨相关的主要致病生物。这种新出现的疾病在蜜蜂体内复制，导致翅膀变形，寿命缩短，并导致英国相当大的蜂群死亡。最近在大黄蜂中发现了这两种致病微生物。因此，蜜蜂和DWV都对英国的主要传粉媒介构成了重大威胁。传粉媒介疾病的研究通常集中在单物种相互作用（一种疾病生物体和一种传粉媒介物种）。然而，大多数寄生虫有多个宿主，大多数宿主也有多个寄生虫。在这里，我们将采取多学科的、基于生态系统的方法来了解这两种主要疾病生物体，N. ceranae和DWV的毒力（例如寿命缩短）和传播，以及它们之间对英国主要授粉服务提供者：蜜蜂和大黄蜂的有害协同作用。我们将进行实验室流行病学实验（研究疾病生物体对其宿主的影响以及疾病从最初感染到宿主死亡或恢复的进展），最先进的“后基因组”分析和高分辨率雷达跟踪单个昆虫，以确定疾病的毒性和传播。利用这些数据，我们将参数化一个新的流行病学模型，该模型将允许对英国传粉媒介上的这些新兴疾病进行风险评估。利用蜜蜂和DWV的全基因组，我们将在全国范围内进行传粉媒介的筛选，为当前疾病毒株流行提供证据基础。我们还将改进应对疾病影响的创新方法。具体来说，我们将研究“乳酸菌”（健康蜜蜂肠道中天然存在的“好家伙”）和所谓的RNAi技术（RNA干扰-可能干扰宿主内病毒复制的短片段RNA）在治疗蜜蜂中的作用，这将为这些疾病生物体提供长期可持续的解决方案。耗资约160万英镑（75% FEC），这个跨学科项目将结合英国三个领先的蜜蜂和授粉研究小组的专业知识，分别是贝尔法斯特女王大学、伦敦皇家霍洛威大学和洛桑研究所的数学建模师（皇家霍洛威）、隆德大学（瑞典）的开创性微生物学家和蜜蜂疾病RNAi技术的世界领导者：蜂学（美国）。它将阐明两种日益重要的寄生虫对英国主要昆虫传粉者的影响和流行病学。研究结果将为政府（保护和农业咨询机构）和主要利益相关者（养蜂人、大黄蜂进口商）制定减轻疾病战略的政策提供证据基础。除了作为新兴传粉媒介疾病的模型研究外，项目结果将直接用于畜牧业实践和减轻疾病影响的方法。

The mysterious death of thousands of honey bee colonies in the USA in the winter of 2005/06, termed Colony Collapse Disorder, focused media attention on the plight of bees, the world's primary pollinators. In the UK, both the honey bee and the 24 species of bumble bee play a major role in crop and wildflower pollination, and both have been suffering serious declines. Exotic (non-native) and newly emergent (native, but with increasing virulence) diseases are considered a major cause of decline in bees and consequently they are one of the greatest challenges to bees in the UK. The single-celled microsporidian 'fungus' Nosema ceranae is an exotic infectious disease of the honey bee that primarily attacks the gut of the bee. We have shown that it has spread worldwide, including the UK, within the last ca. 10 years, and it has been implicated in honey bee colony collapses in the USA (2005/06) and Spain (2007/08). Deformed Wing Virus (DWV) is the major disease organism associated with Varroa destructor mites of honey bees. This emergent disease replicates inside the bee, causing deformed wings and reduced longevity and is responsible for considerable honey bee colony mortality in the UK. Both disease organisms have recently been detected in bumble bees. Thus, both N. ceranae and DWV pose major threats to the UK's principal pollinators. Investigations of pollinator diseases typically focus on single-species interactions (one disease organism and one pollinator species). However, most parasites have multiple hosts and most hosts have multiple parasites. Here, we will take a multidisciplinary, ecological systems-based approach to understand the virulence (e.g. reduced longevity) and transmission of these two major disease organisms, N. ceranae and DWV, and detrimental synergies between them, on the UK's major pollination service providers: the honey bee and bumble bees. We will undertake laboratory epidemiological experiments (in which we look at the impact of a disease organism(s) on its host and the progression of disease from initial infection through to host mortality or recovery), state-of-the-art 'post-genomic' analyses and high-resolution radar tracking of individual insects to determine disease virulence and transmission. Using these data, we will parameterise a novel epidemiological model that will allow risk assessment of these emergent diseases on UK pollinators. Taking advantage of the complete genomes of both N. ceranae and DWV, we will undertake country-wide screening of pollinators to provide the evidence base of current disease strain prevalence. We will also refine innovative approaches for combating disease impacts. Specifically we will investigate the role of 'lactic acid bacteria' (the 'good guys' found naturally in healthy bee guts) and so-called RNAi technology (=RNA interference - short stretches of RNA that may interfere with viral replication inside a host) in curing bees of N. ceranae and DWV, which would provide long-term sustainable solutions to these disease organisms. For ca. £1.6 million (75% FEC), this interdisciplinary project will combine expertise from three leading UK bee and pollination research groups at Queen's University Belfast, Royal Holloway University of London and Rothamsted Research with mathematical modellers (Royal Holloway), pioneering microbiologists at the University of Lund (Sweden) and the world leader in RNAi technologies for bee diseases: Beeologics (USA). It will elucidate the impact and epidemiology of two increasingly important parasites on the UK's principal insect pollinators. Results will provide the evidence base for policy on disease mitigation strategies for government (conservation and agricultural advisory bodies) and major stakeholders (beekeepers, bumble bee importers). As well as serving as a model study of emergent pollinator diseases, project results will feed directly into husbandry practices and approaches to mitigate disease impact.