Thermoregulation of individual paper wasps (Polistes dominula) plays an important role in nest defence and dominance battles

Abstract

Paper wasps, like Polistes dominula, are considered as primitively eusocial. Hence, they are often used as model species for studies about the evolution of eusociality and dominance hierarchies. However, our knowledge about basic physiological processes in these wasps remains limited. In particular, the thermoregulation of individual wasps in their natural habitat has not yet been investigated in detail. We conducted a comprehensive field study to test their ability to respond to external hazards with elevated thorax temperatures. We presented artificial threats by applying smoke or carbon dioxide simulating fire and predator attacks, respectively, and monitored the thorax temperature of wasps on the nest using infrared thermography. We found that P. dominula workers recognized smoke and CO2 and reacted almost instantaneously and simultaneously with an increase of their thorax temperature. The maximal thorax temperature was reached about 65 s after the application of both stressors, but subsequently, the wasps showed a different behaviour pattern. No rise of the thorax temperature was detectable after an air blast was applied or in wasps resting on the nest. These observations provide evidence that P. dominula is able to heat up its thorax and that thermoregulation is employed in escape and defence reactions. Additionally, we investigated the thorax temperatures of queens during dominance battles. We found that the thorax temperature of the dominant queens rose up to 5 °C compared to that of subordinate queens that attacked the former, suggesting that the dominant queen defends herself as well as her nest.

Respiration and metabolism of the resting European paper wasp (Polistes dominulus)

“…In addition, a low SMR is probably beneficial in the energy-extensive lifestyle of the European paper wasp (see Reinhold 1999 ). The animals show long periods of rest and are hardly endothermic on the nest (our own observations; compare Höcherl and Tautz 2015 ). They do not actively heat to achieve a constant nest temperature for accelerated brood development even at lower ambient temperatures and protect the nest only from overheating when it gets hot.…”

“…Individuals also spend much time sitting on the nest and often rest whilst foraging. They do not show endothermic thermoregulation even in cool nights—probably because the produced heat would be immediately lost to the environment (our own unpublished data; Höcherl and Tautz 2013 , 2015 ). Therefore, it is important to know the impact of factors such as environmental conditions and way of life on energetic costs.…”

Nesting behavior of the paper waspPolistes dominulain Central Europe—a flexible system for expanding into new areas

“…Gamboa et al (2002Gamboa et al ( , 2004 compared P. dominula with the native P. fuscatus at the Oakland University preserve (Rochester, Michigan, USA) with respect to the productivity of single-and multiple-foundress colonies, renesting frequencies after natural predation by raccoons as well as egg, larval and pupal developmental times and found the invasive species to be the winner in all categories. In this context, it should be mentioned that a notable feature of individual P. dominula wasps is their capability to heat up their thoraces and to employ thermoregulation in escape and defense reactions (Hö cherl and Tautz 2015).…”

The Thermoregulatory Behavior of Nectar Foraging Polistine Wasps (Polistes dominula and Polistes gallicus) in Different Climate Conditions

“…We wanted to show exemplarily the relation between microclimate parameters and body temperature regulation. Although it is known that Polistine wasps are capable of endothermic heat generation [3,4,5], their thermoregulatory behavior during foraging under natural conditions is hardly explored. Kovac et al [1] investigated the thermoregulation of water foraging paper wasps ( Polistes dominula ) and presented some data on Polistes dominula foraging nectar on raspberry and plant sap on rhubarb [1,20].…”

“…In contrast to Vespine wasps, which achieve a high agility by means of endothermic heat production [1,2], the body temperature of Polistine wasps depends much more on the ambient temperature. In certain cases, however, it was found to be elevated above the ambient temperature to some extent, for example, during flight at laboratory conditions [3,4], during alert or nest defense [5], and when collecting water [1]. While it is clear that an insect of the size of a Polistes wasp is endothermic during flight, e.g., [6,7,8,9], because of the high flight energy expenditure [7], it is unknown whether they improve their agility during foraging for nectar by an elevated thoracic temperature.…”