Data from: How ants acclimate: impact of climatic conditions on the cuticular hydrocarbon profile

1. Organisms from temperate zones are exposed to seasonal changes and must be able to cope with a wide range of climatic conditions. Especially ectotherms, including insects, are at risk to desiccate under dry and warm conditions, the more so given the changing climate. 2. To adjust to current conditions, organisms acclimate through changes in physiology, morphology and/or behaviour. Insects protect themselves against desiccation through a layer of cuticular hydrocarbons (CHC) on their body surface. Hence, acclimation may also affect the CHC profile, changing their waterproofing capacity under different climatic conditions. 3. Here, we investigated the acclimation response of two Temnothorax ant species to different climatic conditions. We analysed CHC profiles of queens, nurses and foragers that were acclimated to different humidity x temperature regimes, and tested the beneficial acclimation hypothesis by measuring survival of workers under desiccation-heat stress. 4. Both ants possessed a species-specific CHC profile. Nevertheless, they showed similar acclimation responses concerning changes of certain CHC classes, and finally similar survival rates under desiccation-heat stress. Warm-acclimated individuals generally showed longer n-alkanes, fewer dimethyl alkanes, and more (workers) or less (queens) monomethyl alkanes. In contrast, dry conditions resulted in more n-alkanes and fewer mono- and dimethyl alkanes, but these acclimatory changes were only observed in workers and not in queens. Warm- and dry-acclimated workers survived desiccation-heat stress better, but we found no species differences. 5. Our results indicate that both ant species can plastically adjust their cuticular hydrocarbon profile, allowing them to acclimate to different climatic conditions. Although their CHC composition differs in a species-specific manner, they showed similar chemical adjustments and concomitant changes in survival rate. Hence, chemical plasticity may be critical to determine a species’ climatic range and its survival under changing climatic conditions.

1. 温带生物会暴露于季节变化之中，必须能够应对多样的气候条件。尤其是变温动物（ectotherms），包括昆虫在内，在干燥温暖的环境下存在脱水风险，而气候变化进一步加剧了这一风险。
2. 为适应当前环境，生物会通过生理、形态或行为层面的变化进行驯化。昆虫可通过体表的表皮碳氢化合物（cuticular hydrocarbons, CHC）层抵御脱水。因此，驯化过程也可能影响CHC图谱，使其在不同气候条件下改变防水能力。
3. 本研究探究了两种扁胸切叶蚁属（Temnothorax）蚂蚁对不同气候条件的驯化响应。我们分析了经不同湿度-温度环境驯化后的蚁后、护理工蚁与觅食工蚁的CHC图谱，并通过测定工蚁在干燥热胁迫下的存活率，检验了有益驯化假说。
4. 两种蚂蚁均拥有物种特异性的CHC图谱。尽管如此，二者在特定CHC类别的变化上展现出相似的驯化响应，最终在干燥热胁迫下的存活率也相近。经温暖环境驯化的个体通常拥有更长的正构烷烃（n-alkanes）、更少的二甲基烷烃，且工蚁的一甲基烷烃更多、蚁后的一甲基烷烃更少。与之相反，干燥环境会导致正构烷烃增多、单/二甲基烷烃减少，但这类驯化变化仅在工蚁中观测到，蚁后中并未出现。经温暖和干燥环境驯化的工蚁在干燥热胁迫下的存活率更高，但未发现物种间的差异。
5. 我们的研究结果表明，两种蚂蚁均可通过表型可塑性调整其表皮碳氢化合物图谱，从而适应不同的气候条件。尽管它们的CHC组成具有物种特异性，但二者展现出了相似的化学调节机制，并伴随存活率的相应变化。因此，化学可塑性或许是决定物种气候分布范围及其在气候变化下存活率的关键因素。