Straw Edward A, Brown Mark J F
Department of Biological Sciences, School of Life Sciences and the Environment, Royal Holloway University of London, Egham, United Kingdom.
PeerJ. 2021 Nov 17;9:e12486. doi: 10.7717/peerj.12486. eCollection 2021.
Glyphosate is the world's most used pesticide and it is used without the mitigation measures that could reduce the exposure of pollinators to it. However, studies are starting to suggest negative impacts of this pesticide on bees, an essential group of pollinators. Accordingly, whether glyphosate, alone or alongside other stressors, is detrimental to bee health is a vital question. Bees are suffering declines across the globe, and pesticides, including glyphosate, have been suggested as being factors in these declines.
Here we test, across a range of experimental paradigms, whether glyphosate impacts a wild bumble bee species, . In addition, we build upon existing work with honey bees testing glyphosate-parasite interactions by conducting fully crossed experiments with glyphosate and a common bumble bee trypanosome gut parasite, . We utilised regulatory acute toxicity testing protocols, modified to allow for exposure to multiple stressors. These protocols are expanded upon to test for effects on long term survival (20 days). Microcolony testing, using unmated workers, was employed to measure the impacts of either stressor on a proxy of reproductive success. This microcolony testing was conducted with both acute and chronic exposure to cover a range of exposure scenarios.
We found no effects of acute or chronic exposure to glyphosate, over a range of timespans post-exposure, on mortality or a range of sublethal metrics. We also found no interaction between glyphosate and in any metric, although there was conflicting evidence of increased parasite intensity after an acute exposure to glyphosate. In contrast to published literature, we found no direct impacts of this parasite on bee health. Our testing focussed on mortality and worker reproduction, so impacts of either or both of these stressors on other sublethal metrics could still exist.
Our results expand the current knowledge on glyphosate by testing a previously untested species, , using acute exposure, and by incorporating a parasite never before tested alongside glyphosate. In conclusion our results find that glyphosate, as an active ingredient, is unlikely to be harmful to bumble bees either alone, or alongside .
草甘膦是全球使用最广泛的农药，在使用时未采取可减少传粉者接触该农药的缓解措施。然而，研究开始表明这种农药对蜜蜂（传粉者的重要群体）有负面影响。因此，草甘膦单独或与其他应激源一起是否对蜜蜂健康有害是一个至关重要的问题。全球蜜蜂数量正在减少，包括草甘膦在内的农药被认为是导致这些减少的因素之一。
在此，我们通过一系列实验范式测试草甘膦是否会影响一种野生熊蜂物种。此外，我们在现有针对蜜蜂测试草甘膦与寄生虫相互作用的工作基础上，通过对草甘膦和一种常见的熊蜂肠道锥虫寄生虫进行完全交叉实验。我们采用了经过调整的监管急性毒性测试方案，以允许接触多种应激源。这些方案经过扩展以测试对长期存活（20天）的影响。使用未交配工蜂的微群落测试被用于测量任一应激源对繁殖成功率指标的影响。这种微群落测试在急性和慢性暴露条件下均进行，以涵盖一系列暴露情况。
我们发现，在暴露后的一系列时间跨度内，急性或慢性接触草甘膦对死亡率或一系列亚致死指标均无影响。我们还发现草甘膦与在任何指标上均无相互作用，尽管有相互矛盾的证据表明急性接触草甘膦后寄生虫强度增加。与已发表的文献相反，我们发现这种寄生虫对蜜蜂健康没有直接影响。我们的测试集中在死亡率和工蜂繁殖上，因此这两种应激源中的一种或两种对其他亚致死指标的影响可能仍然存在。
我们的研究结果通过测试一个此前未测试过的物种，采用急性暴露，并纳入一种此前从未与草甘膦一起测试过的寄生虫，扩展了当前关于草甘膦的知识。总之，我们的研究结果表明，草甘膦作为一种活性成分，单独或与一起，都不太可能对熊蜂有害。
