Institute of Nature Conservation Polish Academy of Sciences, al. Adama Mickiewicza 33, 31-120, Kraków, Poland.
Evolutionary Stress Ecology and Ecotoxicology, University of Leuven, Leuven, Belgium.
Sci Rep. 2024 Oct 19;14(1):24565. doi: 10.1038/s41598-024-76057-x.
In seasonal environments, organisms with complex life cycles not only contend with seasonal time constraints (TC) but also increasingly face global change stressors that may interfere with responses to TC. Here, we tested how warming and predator stress imposed during the egg and larval stages shaped life history and behavioural responses to TC in the temperate damselfly Ischnura elegans. Eggs from early and late clutches in the season were subjected to ambient and 4 °C warming temperature and the presence or absence of predator cues from perch and signal crayfish. After hatching, larvae were retained at the same thermal regime, and the predator treatment was continued or not up to emergence. The late eggs decreased their development time, especially under warming and when not exposed to predator cues. However, the late eggs increased their development time when exposed to predator cues, especially to crayfish cues. The TC decreased survival of late larvae that were as eggs exposed to crayfish cues, indicating a carry-over effect. The TC and warming additively reduced late larvae development time to emergence. Independent of the TC, predator cue effects on development time were stronger during the egg than during the larval stage. The late individuals expressed lower mass at emergence, which mirrored the size difference between field-collected mothers. Warming caused a higher mass at emergence. The late individuals increased their boldness and showed a higher number of moves, whereas warming caused a decreased boldness. There was no predator cue effect on larval behaviour. The results indicate that late individuals compensate for late season egg laying, which is facilitated under warming but counteracted under predation risk, especially when imposed by the crayfish.
在季节性环境中，具有复杂生命周期的生物不仅要应对季节性时间限制 (TC)，还要应对可能干扰其对 TC 响应的全球变化压力。在这里，我们测试了在卵期和幼虫期施加的变暖和捕食者压力如何塑造温带蜻蜓伊蚊的生活史和对 TC 的行为反应。在季节早期和晚期的卵被置于环境温度和 4°C 的升温以及鲈鱼和信号小龙虾的捕食者线索的存在或不存在的情况下。孵化后，幼虫保留在相同的热区，继续或不继续进行捕食者处理，直到成虫。晚期卵缩短了发育时间，尤其是在变暖且未暴露于捕食者线索的情况下。然而，当暴露于捕食者线索，尤其是小龙虾线索时，晚期卵会增加其发育时间。TC 降低了暴露于小龙虾线索的卵期晚期幼虫的存活率，表明存在滞后效应。TC 和变暖都会加速晚期幼虫到成虫的发育时间。独立于 TC，捕食者线索对发育时间的影响在卵期强于幼虫期。晚期个体在成虫时的质量较低，反映了野外采集的母体之间的大小差异。变暖导致成虫时的质量增加。晚期个体表现出更高的胆量并进行更多的移动，而变暖导致胆量降低。幼虫行为不受捕食者线索的影响。结果表明，晚期个体补偿了晚期产卵，这在变暖的情况下得到促进，但在捕食风险下受到抵消，尤其是在小龙虾施加的情况下。
