Effects of desiccation and starvation stress on thermal tolerance in the forest ant Aphaenogaster picea

Global climate change is expected to impact ecosystems and result in more extreme weather over the coming decades, with increases in mean temperature accompanied by larger fluctuations in precipitation that together may impose more significant physiological stress on resident species than each factor alone. We examined how desiccation stress and resource limitation impact thermal tolerance in a common northeastern U.S. forest ant, Aphaenogaster picea.  We experimentally desiccated or starved individual workers, and compared their survival and heat shock gene expression profiles following exposure to the acute upper thermal limit for this species (40 degrees C) to that of non-treated controls.   Understanding the extent of cross-talk between different stress-response mechanisms may better inform predictive models of organismal responses to future climatic shifts.