Does the Aggregation Behavior of Overwintering Paper Wasp Gynes Provide Energetic Benefits?

In temperate regions, paper wasp gynes (Polistes dominula) move to protected shelters in late autumn for the purpose of overwintering. Overwintering represents an energetic challenge for insects, which require sufficient energy reserves to survive the cold season. The aggregation behavior exhibited by overwintering insects is associated with a number of benefits, including the buffering of temperature fluctuations and low humidity. This, in turn, has the effect of reducing desiccation stress and improving overwintering success by reducing energetic costs. The metabolic rates of individual insects can vary between separated individuals and aggregations, with a decline in metabolic rate observed within larger groups. We investigated the metabolism of paper wasp gynes in order to detect energy savings during overwintering. We measured the CO₂ production (measure of energy use) of single wasps and aggregations of wasps at three different temperatures (4, 8, 12 °C). Evidence suggests a close relationship between metabolism and locomotor activity; therefore, activity observations were made during the course of experiments. Metabolic rate increased with ambient temperature in a typical exponential course in both singles and aggregations. However, in contrast to the findings of other studies, no difference in metabolism was observed between singles and aggregations. Furthermore, activity scores revealed higher activity levels in aggregations. This indicates that energetic requirements are not the underlying cause of the aggregation behavior exhibited by overwintering paper wasp gynes.

The online version contains supplementary material available at 10.1007/s10905-025-09895-w.