Strobl Verena, Camenzind Domenic, Minnameyer Angela, Walker Stephanie, Eyer Michael, Neumann Peter, Straub Lars
Institute of Bee Health, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland.
Laboratory of Soil Biodiversity, University of Neuchâtel, 2000 Neuchâtel, Switzerland.
Insects. 2020 Nov 20;11(11):819. doi: 10.3390/insects11110819.
The ubiquitous use of pesticides is one major driver for the current loss of biodiversity, and the common practice of simultaneously applying multiple agrochemicals may further contribute. Insect toxicology currently has a strong focus on survival to determine the potential hazards of a chemical routinely used in risk evaluations. However, studies revealing no effect on survival or even indicating enhanced survival are likely to be misleading, if potential trade-offs between survival and other physiological factors are overlooked. Here, we used standard laboratory experiments to investigate the sublethal (i.e., food consumption) and lethal (i.e., survival) effects of two common agricultural pesticides (Roundup and clothianidin) on adult female solitary bees, . The data showed no significant effect of the treatment on cumulative survival; however, a significant positive correlation between herbicide and insecticide exposure and age was revealed, i.e., bees exposed to higher dosages lived longer. As no significant differences in daily food consumption were observed across treatment groups, increased food intake can be excluded as a factor leading to the prolonged survival. While this study does not provide data on fitness effects, two previous studies using solitary bees observed significant negative effects of neonicotinoid insecticides on fitness, yet not on survival. Thus, we conjecture that the observed non-significant effects on longevity may result from a trade-off between survival and reproduction. The data suggest that a focus on survival can lead to false-negative results and it appears inevitable to include fitness or at least tokens of fitness at the earliest stage in future risk assessments.
农药的广泛使用是当前生物多样性丧失的一个主要驱动因素，同时使用多种农用化学品的常见做法可能会进一步加剧这种情况。昆虫毒理学目前非常注重通过存活率来确定在风险评估中常规使用的一种化学品的潜在危害。然而，如果忽视了存活率与其他生理因素之间可能存在的权衡，那么那些显示对存活率没有影响甚至表明存活率提高的研究可能会产生误导。在此，我们通过标准实验室实验，研究了两种常见农用农药（草甘膦除草剂和噻虫胺杀虫剂）对成年雌性独居蜂的亚致死效应（即食物消耗）和致死效应（即存活率）。数据显示，处理对累积存活率没有显著影响；然而，除草剂和杀虫剂暴露与年龄之间存在显著的正相关关系，即接触较高剂量农药的蜜蜂寿命更长。由于各处理组之间在每日食物消耗方面未观察到显著差异，因此可以排除食物摄入量增加是导致寿命延长的一个因素。虽然本研究没有提供关于适合度效应的数据，但此前两项针对独居蜂的研究发现，新烟碱类杀虫剂对适合度有显著负面影响，但对存活率没有影响。因此，我们推测观察到的对寿命无显著影响可能是存活率与繁殖率之间权衡的结果。数据表明，仅关注存活率可能会导致假阴性结果，并且在未来的风险评估中，尽早纳入适合度或至少是适合度的指标似乎是不可避免的。
