Energetics of Paper Wasps (Polistes sp.) from Differing Climates during the Breeding Season

SIMPLE SUMMARY: Paper wasps are widely distributed in nearly all regions of Europe. They are found in the warm Mediterranean, and in the harsh Alpine climate. Some species are very careful in the choice of nesting sites to ensure a proper development of the brood. We investigated microclimate conditions at the nests of three species (P. dominula, P. gallicus, P. biglumis) from differing climates, in order to characterize fine-scale environment conditions and conduct energetic calculations for an entire breeding season. The microclimate conditions (temperature) at the nests differed significantly in the Mediterranean, temperate, and Alpine habitats, but in all habitats the mean ambient nest temperatures were about 2 to 3 °C above the standard meteorological climate data. The wasps’ energetic expenditure depended strongly on temperature. P. gallicus from the warm Mediterranean climate exhibited the highest energetic costs, whereas P. biglumis from the harsh Alpine climate had the lowest costs during a breeding season. The energetic expenditure of P. dominula from the temperate climate was somewhat lower than in the Mediterranean species, but clearly higher than in the Alpine species. Temperature increase due to climate change may have a severe impact on the wasps’ survival as energetic costs increase. ABSTRACT: Paper wasps are widely distributed in Europe. They live in the warm Mediterranean, and in the harsh Alpine climate. Some species are very careful in their choice of nesting sites to ensure a proper development of the brood. We investigated microclimate conditions at the nests of three species (P. dominula, P. gallicus, P. biglumis) from differing climates, in order to characterize environmental conditions and conduct energetic calculations for an entire breeding season. The mean ambient nest temperature differed significantly in the Mediterranean, temperate, and Alpine habitats, but in all habitats it was about 2 to 3 °C above the standard meteorological data. The energetic calculations of adult wasps’ standard and active metabolic rate, based on respiratory measurements, differed significantly, depending on the measured ambient temperatures or the wasps’ body temperatures. P. gallicus from the warm Mediterranean climate exhibited the highest energetic costs, whereas P. biglumis from the harsh Alpine climate had the lowest costs. Energetic costs of P. dominula from the temperate climate were somewhat lower than those in the Mediterranean species, but clearly higher than those in the Alpine species. Temperature increase due to climate change may have a severe impact on the wasps’ survival as energetic costs increase.