Pardikes Nicholas A, Revilla Tomas A, Proudhom Gregoire, Thierry Melanie, Lue Chia-Hua, Hrcek Jan
Biology Centre of the Czech Academy of Sciences, Institute of Entomology, Ceske Budejovice, Czech Republic.
Department of Biology, Utah State University, Logan, UT, USA.
Oecologia. 2025 Aug 12;207(9):141. doi: 10.1007/s00442-025-05781-6.
Due to ongoing climate change, extreme climatic events are expected to increase in magnitude and frequency. While individual species' responses to thermal extremes are widely studied, the impact of extreme heat events on species interactions and the key functions they provide in communities is understudied. As outcomes of species interactions depend on coordinated physiology and development, the consequences of heat exposure are likely impacted by its timing relative to the organisms' life history traits, but to what extent is unclear. In this study, we evaluate how the timing of heat exposure affects interactions among nine tropical Drosophila-parasitoid species combinations using laboratory microcosm experiments. Interactions were most affected when heat exposure coincided with parasitism, leading to decreased parasitism rates. Parasitism rates also dropped when extreme heat occurred after parasitism in one instance. Experiencing heat exposure before parasitism had little effect. Using a simulation model, we determined that the combined effects of parasitism and heat exposure are generally additive, with no evidence of delayed consequences of heat exposure early in development on parasitism outcomes. Furthermore, we found adult host flies and parasitoids more resistant to heat exposure than their larval stages. Thus, whether more frequent extreme heat events disrupt species interactions globally will depend on their exact timing relative to ontogenetic stages and interactions. Heat exposure impacts the two trophic levels differently. Thus, when heat exposure coincides with parasitism, it may diminish the ability of parasitoids to control their hosts, affecting both natural ecosystems and agricultural environments.
由于气候变化持续,极端气候事件预计在强度和频率上都会增加。虽然单个物种对极端温度的反应已得到广泛研究,但极端高温事件对物种相互作用及其在群落中所提供的关键功能的影响却研究不足。由于物种相互作用的结果取决于协调的生理和发育过程,热暴露的后果可能会受到其相对于生物体生活史特征的时间安排的影响,但具体程度尚不清楚。在本研究中,我们通过实验室微观实验评估热暴露的时间如何影响九种热带果蝇 - 寄生蜂物种组合之间的相互作用。当热暴露与寄生行为同时发生时,相互作用受到的影响最大,导致寄生率下降。在一个实例中,寄生后出现极端高温时,寄生率也会下降。寄生前经历热暴露影响不大。通过模拟模型,我们确定寄生和热暴露的综合影响通常是相加的,没有证据表明发育早期的热暴露对寄生结果有延迟影响。此外,我们发现成年寄主果蝇和寄生蜂比它们的幼虫阶段对热暴露更具抵抗力。因此,更频繁的极端高温事件是否会在全球范围内破坏物种相互作用将取决于它们相对于个体发育阶段和相互作用的确切时间。热暴露对两个营养级的影响不同。因此,当热暴露与寄生行为同时发生时,可能会削弱寄生蜂控制其寄主的能力,从而影响自然生态系统和农业环境。