Weaving Hester, Lord Jennifer S, Haines Lee, English Sinead
School of Biological Sciences University of Bristol Bristol UK.
Department of Vector Biology Liverpool School of Tropical Medicine Liverpool UK.
Ecol Evol. 2023 Oct 18;13(10):e10652. doi: 10.1002/ece3.10652. eCollection 2023 Oct.
Thermal stress during development can prime animals to cope better with similar conditions in later life. Alternatively, negative effects of thermal stress can persist across life stages and result in poorer quality adults (negative carryover effects). As mean temperatures increase due to climate change, evidence for such effects across diverse taxa is required. Using , a species of tsetse fly and vector of trypanosomiasis, we asked whether (i) adaptive developmental plasticity allows flies to survive for longer under food deprivation when pupal and adult temperatures are matched; or (ii) temperature stress during development persists into adulthood, resulting in a greater risk of death. We did not find any advantage of matched pupal and adult temperature in terms of improved starvation tolerance, and no direct negative carryover effects were observed. There was some evidence for indirect carryover effects-high pupal temperature produced flies of lower body mass, which, in turn, resulted in greater starvation risk. However, adult temperature had the largest impact on starvation tolerance by far: flies died 60% faster at 31°C than those experiencing 25°C, consequently reducing survival time from a median of 8 (interquartile range (IQR) 7-9) to 5 (IQR 5-5.25) days. This highlights differences in temperature sensitivity between life stages, as there was no direct effect of pupal temperature on starvation tolerance. Therefore, for some regions of sub-Saharan Africa, climate change may result in a higher mortality rate in emerging tsetse while they search for their first blood meal. This study reinforces existing evidence that responses to temperature are life stage specific and that plasticity may have limited capacity to buffer the effects of climate change.
发育过程中的热应激可使动物更好地应对日后生活中类似的环境条件。或者，热应激的负面影响可能会贯穿生命阶段，导致成年个体质量下降（负面遗留效应）。随着气候变化导致平均气温上升，需要有不同分类群中此类效应的证据。我们以采采蝇（一种锥虫病的传播媒介）为研究对象，探究：（i）适应性发育可塑性是否能让采采蝇在蛹期和成虫期温度匹配时，在食物匮乏的情况下存活更长时间；或者（ii）发育过程中的温度应激是否会持续到成年期，从而导致更高的死亡风险。我们没有发现蛹期和成虫期温度匹配在提高饥饿耐受性方面有任何优势，也未观察到直接的负面遗留效应。有一些间接遗留效应的证据——蛹期温度高会导致羽化出的采采蝇体重较低，进而导致饥饿风险增加。然而，成虫期温度对饥饿耐受性的影响最大：在31°C环境下的采采蝇死亡速度比处于25°C环境下的快60%，因此存活时间从中位数8天（四分位间距（IQR）7 - 9天）降至5天（IQR 5 - 5.25天）。这凸显了不同生命阶段对温度敏感性的差异，因为蛹期温度对饥饿耐受性没有直接影响。因此，对于撒哈拉以南非洲的一些地区，气候变化可能会导致新羽化的采采蝇在寻找第一顿血餐时死亡率更高。这项研究强化了现有证据，即对温度的反应具有生命阶段特异性，可塑性可能在缓冲气候变化影响方面能力有限。
