Department of Environmental Science, Policy, and Management, 130 Mulford Hall, #3114, University of California, Berkeley, Berkeley, CA 94720-3114, USA.
Institute for Evolution and Biodiversity, University of Muenster, Hüfferstr. 1, D-48149 Münster, Germany.
J Exp Biol. 2023 Aug 15;226(16). doi: 10.1242/jeb.245578. Epub 2023 Aug 21.
An insect's cuticle is typically covered in a layer of wax prominently featuring various hydrocarbons involved in desiccation resistance and chemical communication. In Argentine ants (Linepithema humile), cuticular hydrocarbons (CHCs) communicate colony identity, but also provide waterproofing necessary to survive dry conditions. Theory suggests different CHC compound classes have functional trade-offs, such that selection for compounds used in communication would compromise waterproofing, and vice versa. We sampled sites of invasive L. humile populations from across California to test whether CHC differences between them can explain differences in their desiccation survival. We hypothesized that CHCs whose abundance was correlated with environmental factors would determine survival during desiccation, but our regression analysis did not support this hypothesis. Interestingly, we found the abundance of most CHCs had a negative correlation with survival, regardless of compound class. We suggest that the CHC differences between L. humile nests in California are insufficient to explain their differential survival against desiccation, and that body mass is a better predictor of desiccation survival at this scale of comparison.
昆虫的外骨骼通常覆盖着一层蜡质，其中突出的是各种参与抗干燥和化学通讯的碳氢化合物。在阿根廷蚂蚁（Linepithema humile）中，表皮碳氢化合物（CHC）传达着群体身份，但也提供了在干燥条件下生存所需的防水性。理论表明，不同的 CHC 化合物类具有功能上的权衡，例如，用于通讯的化合物的选择会损害防水性，反之亦然。我们从加利福尼亚各地采集了入侵的 L. humile 种群的样本，以测试它们之间的 CHC 差异是否可以解释它们在干燥条件下的生存差异。我们假设与环境因素相关的 CHC 丰度会决定干燥期间的生存，但我们的回归分析并不支持这一假设。有趣的是，我们发现大多数 CHC 的丰度与生存呈负相关，而不管化合物类如何。我们认为，加利福尼亚 L. humile 巢穴之间的 CHC 差异不足以解释它们在抗干燥方面的差异生存，并且在这种比较规模下，体重是干燥生存的更好预测指标。
