School of Biological Sciences, Royal Holloway University of London, Egham, TW20 0EX, UK.
Botany and Plant Science, School of Natural Sciences and Ryan Institute, National University of Ireland Galway, Galway, Ireland.
Sci Rep. 2017 Aug 14;7(1):8005. doi: 10.1038/s41598-017-08752-x.
Neonicotinoid pesticides are used in agriculture to reduce damage from crop pests. However, beneficial insects such as bees can come into contact with these pesticides when foraging in treated areas, with potential consequences for bee declines and pollination service delivery. Honeybees are typically used as a model organism to investigate insecticide impacts on bees, but relatively little is known about impacts on other taxa such as bumblebees. In this experiment, we chronically exposed whole mature bumblebee (Bombus terrestris) colonies to field-realistic levels of the neonicotinoid thiamethoxam (2.4ppb & 10ppb) over four weeks, and compared colony growth under laboratory conditions. We found no impact of insecticide exposure on colony weight gain, or the number or mass of sexuals produced, although colonies exposed to 2.4ppb produced larger males. As previous studies have reported pesticide effects on bumblebee colony growth, this may suggest that impacts on bumblebee colonies are more pronounced for colonies at an earlier stage in the reproductive cycle. Alternatively, it may also indicate that thiamethoxam differs in toxicity compared to previously tested neonicotinoids in terms of reproductive effects. In either case, assessing bumblebee colony development under field conditions is likely more informative for real world scenarios than tests conducted in laboratory conditions.
新烟碱类农药在农业中被用于减少作物害虫造成的损害。然而，当有益昆虫（如蜜蜂）在施药区域觅食时，可能会接触到这些农药，这可能对蜜蜂数量减少和授粉服务的提供产生潜在影响。蜜蜂通常被用作研究杀虫剂对蜜蜂影响的模式生物，但对其他类群（如熊蜂）的影响知之甚少。在这项实验中，我们将成熟的熊蜂（Bombus terrestris）整个群体在四周内持续暴露于田间实际水平的新烟碱类农药噻虫嗪（2.4ppb 和 10ppb）中，并在实验室条件下比较了群体的生长情况。我们发现杀虫剂暴露对群体体重增加或产生的性别的数量或质量没有影响，尽管暴露于 2.4ppb 的群体产生了更大的雄性。由于之前的研究报告了杀虫剂对熊蜂群体生长的影响，这可能表明杀虫剂对熊蜂群体的影响在繁殖周期早期的群体中更为明显。或者，这也可能表明噻虫嗪在生殖效应方面与之前测试的新烟碱类农药在毒性上有所不同。在任何一种情况下，在田间条件下评估熊蜂群体的发育情况都比在实验室条件下进行的测试更能为现实情况提供信息。
