Division of labor and low temperatures predict geographic variation in thermal tolerance of a North American paper wasp (Mischocyttarus mexicanus cubicola)

A recent study explores how biogeographic factors and social structure influence the thermal performance of a North American paper wasp, <source name="paper wasp">Mischocyttarus mexicanus cubicola</source>. By comparing populations across temperate and subtropical climates in eastern North America, researchers aimed to understand how division of labor between foundresses and non-reproductive workers might generate adaptive variation in thermal performance within the colony.

The study focused on two key aspects: cold and heat tolerance. Cold tolerance turned out to be more predictable with environmental temperatures across different latitudes, while heat tolerance showed less variation. Temperate populations faced winter cold comas, whereas subtropical populations did not experience such cold bouts. This difference in cold tolerance suggests that environmental conditions play a significant role in shaping the thermal performance of these wasps.

Moreover, the research revealed that reproductive foundresses within colonies were more cold-tolerant than workers. This division of labor allowed foundresses to remain mobile during cooler periods of early spring, enabling them to complete crucial tasks like nest construction before the emergence of non-reproductive workers. These findings demonstrate that social structure can also impact the thermal performance of organisms, highlighting the importance of considering division of labor in biogeographic studies of organismal thermal performance.