Heat tolerance in social insects: molecular correlates and quantitative frameworks

Thermal limits are key determinants of social insect performance and distribution. Given their ecological importance and considering climate change, interest has grown in identifying the molecular pathways underlying their heat tolerance. Although this field has advanced rapidly over the past decade, important gaps remain. Social insects can stratify thermal environments across castes and through division of labor, yet this feature is rarely considered in current studies. Most studies link omics datasets or candidate pathways expressed during heat stress to endpoints of survival (e.g. upper thermal limits), an approach that is informative but that also limits standardization of thermal injury. In addition, functional validation of key genes, for example, through loss-of-function assays, is still scarce. Here, we summarize current knowledge on molecular heat-stress responses in social insects, highlight major conceptual gaps, and advocate integrating molecular assays with dose-based thermal frameworks to improve predictions of social insect resilience under intensifying thermal extremes.