Behavioural and molecular responses to pesticide exposure in bumblebees.

随着全球人口的增长，对更高农业产量的需求不断增加。施用农药是为了保持作物高产，但我们对目前农药的使用对非目标生物的影响知之甚少，包括访问这些作物的有益授粉者。最重要的传粉者是社会蜜蜂（如蜜蜂和大黄蜂），但它们的数量最近一直在下降，对粮食安全和全球经济构成重大风险。这些下降与农药有关，但迄今为止，还缺乏数据表明田间水平的农药暴露是否真的对蜜蜂产生了影响。田间水平的农药暴露通常对蜜蜂是非致命的;那么我们为什么要担心呢？最近的研究突出表明，接近田间水平的农药可能对蜜蜂个体行为产生亚致死影响。因此，令人担忧的是，这种影响在个体水平上可能对蜂群繁殖和生存产生连锁反应，这可以解释观察到的蜜蜂数量下降。然而，几乎没有研究表明情况是否确实如此。此外，我们仍然缺乏对觅食蜜蜂在行为和分子（遗传）水平上受到影响的方式的了解。不应低估了解农药暴露对觅食性能的微妙或巨大影响的重要性：i）菌落生长直接依赖于有效的觅食，ii）对觅食性能的任何损害对作物和野花的成功授粉都有直接影响。因此，了解农药暴露景观如何影响蜜蜂觅食行为，这如何影响殖民地的成功，以及最终如何塑造蜜蜂种群，是研究的优先事项。我们建议开展五个方面的研究，以解决我们知识中的这些空白。我们的研究系统将是熊蜂（熊蜂属），因为熊蜂是景观中最重要的野生昆虫授粉者之一，也被用于温室授粉。首先，我们将确定杀虫剂是否会降低熊蜂执行复杂授粉任务的能力。其次，我们将确定这是否反过来影响殖民地的增长和繁殖成功。第三，我们将确定接触杀虫剂是否会影响大黄蜂授粉的作物的产量。第四，使用以前只有癌症研究人员才能使用的工具，我们将确定蜜蜂暴露于杀虫剂时发生的分子变化。最后，通过对从英国各地取样的五种野生大黄蜂进行遗传筛查，我们将确定农药对野生大黄蜂种群的影响程度。如果农药暴露引起的觅食行为受损对蜂群健康有影响，那么我们预计会有一个强大的选择压力塑造蜜蜂种群。

With globally growing human populations there is ever increasing demand for higher agricultural yields. Pesticides are applied to maintain high crop yields, but we know little about the effects that current pesticide use has on non-target organisms including the beneficial pollinators that visit these crops. The most important of such pollinators are the social bees (e.g. honey bees and bumble bees) - but their populations have recently been declining, posing important risks for food security and the global economy. Pesticides have been implicated in these declines, yet to date there is a great paucity of data to show whether pesticide exposure at field levels is actually having an effect on bees. Field level pesticide exposure is typically non-lethal to bees; so why should we be concerned? Recent studies have highlighted that pesticides approximating field levels may induce sublethal effects on individual bee behaviour. The concern is therefore that such effects at the individual level may have knock on effects to colony reproduction and survival, and this would explain observed bee declines. However, there are almost no studies that have set out to show whether this is indeed the case. Furthermore, we still lack an understanding about the manner in which foraging bees are affected at both the behavioural and molecular (genetic) level. The importance of understanding the subtle or large effects of pesticide exposure on foraging performance should not be underestimated: i) colony growth relies directly on efficient foraging and ii) any impairment to foraging performance has direct consequences on the successful pollination of crops and wild flowers. It is thus a research priority to know how a pesticide exposure landscape affects bee foraging behaviour, how this affects colony success, and ultimately how this shapes bee populations.We propose to carry out five axes of research that will address these gaps in our knowledge. Our study system will be bumblebees (Bombus spp), as bumblebees are one of the most substantial wild insect pollinators in the landscape, as well as being used for greenhouse pollination. First we will determine whether pesticides reduce the abilities of bumblebees to carry out complex pollination tasks. Second, we will determine whether this in turn affects colony growth and reproductive success. Third, we will determine whether exposure to pesticides affects the yield of the crops bumblebees are pollinating. Fourth, using tools previously only available to cancer researchers, we will identify the molecular changes that occur in bees when they are exposed to pesticides. Finally, by performing genetic screening on five species of wild bumblebees sampled from across the UK we will determine the extent to which pesticides affect wild bumblebee populations. If impairment to foraging behaviour induced by pesticide exposure has an effect on colony fitness then we expect there to be a strong selective pressure shaping bee populations.