Thermotolerance has often been linked to species distribution for a diverse range of organisms. In the context of climate change, assessing heat resistance ability is useful for understanding potential future range shifts and the physiological response of populations. As bumblebee (Bombus) populations have been declining for several decades with several documented range shifts, an assessment of the hyperthermic resistance of species is urgently needed. In this study, we measure in males the heat resistance of ten bumblebee species living in temperate regions (northwestern Europe) with a static temperature methodology to evaluate the time before heat stupor (THS) which corresponds to a chill coma. Our results on heat stress resistance show that not all species are affected in the same way to heat stress. The most widespread species, B. terrestris (median THS 395 min) and B. lucorum (median THS 257 min) are the least sensitive to hyperthermic stress. The resistance time of bumblebee males is up to 10 times longer than the THS for declining species such as B. jonellus (median THS 48 min) and B. magnus (median THS 58 min). We highlight the high interspecific variability of heat resistance in a morphologically homogeneous genus such as bumblebees. From a conservation point of view, our research highlights the urgency for assessing the heat resistance of different species since each one can display a species-specific thermal sensitivity that is likely linked to a risk of decline in the case of heat waves.

中文翻译：

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大黄蜂雄蜂的高温抗逆性：比利时种的测试案例

耐热性通常与多种生物的物种分布有关。在气候变化的背景下，评估耐热能力有助于了解未来潜在的范围变化和人口的生理反应。由于大黄蜂（Bombus）种群数十年来一直在下降，并且有几次记录的范围变化，因此迫切需要评估物种的耐热性。在这项研究中，我们使用静态温度方法测量了生活在温带地区（欧洲西北部）的 10 种雄蜂的耐热性，以评估对应于寒冷昏迷的热昏迷时间 (THS)。我们对热应激抗性的结果表明，并非所有物种都以相同的方式受到热应激的影响。分布最广的物种，B. terrestris（中位 THS 395 分钟）和 B. lucorum（中位 THS 257 分钟）对高温应激最不敏感。熊蜂雄性的抵抗时间比下降物种的 THS 长 10 倍，例如 B. jonellus（中值 THS 48 分钟）和 B. magnus（中值 THS 58 分钟）。我们强调了大黄蜂等形态同质属中耐热性的高种间变异性。从保护的角度来看，我们的研究强调了评估不同物种耐热性的紧迫性，因为每个物种都可以表现出特定于物种的热敏感性，这可能与热浪情况下的衰退风险有关。熊蜂雄性的抵抗时间比下降物种的 THS 长 10 倍，例如 B. jonellus（中值 THS 48 分钟）和 B. magnus（中值 THS 58 分钟）。我们强调了大黄蜂等形态同质属中耐热性的高种间变异性。从保护的角度来看，我们的研究强调了评估不同物种耐热性的紧迫性，因为每个物种都可以表现出特定于物种的热敏感性，这可能与热浪情况下的衰退风险有关。熊蜂雄性的抵抗时间比下降物种的 THS 长 10 倍，例如 B. jonellus（中值 THS 48 分钟）和 B. magnus（中值 THS 58 分钟）。我们强调了大黄蜂等形态同质属中耐热性的高种间变异性。从保护的角度来看，我们的研究强调了评估不同物种耐热性的紧迫性，因为每个物种都可以表现出特定于物种的热敏感性，这可能与热浪情况下的衰退风险有关。