Climate change‐driven body size shrinking in a social wasp

• Published in: Ecological entomology 2020-02, Vol.45 (1), p.130-141
• Main Authors: Polidori, Carlo, Gutiérrez‐Cánovas, Cayetano, Sánchez, Enrique, Tormos, José, Castro, Leopoldo, Sánchez‐Fernández, David
• Format: Article
• Language: English
• Subjects: Adaptation; Body mass; Body size; Body size; Dolichovespula sylvestris; global warming; Spain; wing loading; Climate change; Geographical distribution; Geographical locations; Global warming; Insects; Morphology; Social interactions; Temperature; Vertebrates; Wing loading; Workers (insect caste)
• ISSN: 0307-6946; 1365-2311
• DOI: 10.1111/een.12781

1. Climate change is expected to produce shifts in species distributions as well as behavioural, life‐history, and/or morphological adaptations to find suitable conditions or cope with the altered environment. Most of our knowledge on this issue comes from studies on vertebrates, mainly endotherm species. However, it remains uncertain how small ectotherms, such as insects, respond to increased temperature. 2. This study tested whether climate change over the last 100 years (1904–2013) has affected morphological and functional traits in workers of the social wasp Dolichovespula sylvestris in the Iberian Peninsula. 3. Head width and forewing length, as well as body mass and wing area (assuming no change in shape), decreased over time and with increased mean annual temperature, even when controlling for geographical location and altitude. Interestingly, wing size decreased with a steeper slope compared with body size. If there is no change in wing shape, this would lead to an invariable wing loading (body mass:wing area ratio) over time, with potential consequences on flying ability of more recent (and thus smaller) wasp individuals. 4. These results suggest that recent climate change is leaving morphological signatures in social wasps, increasing the evidence for this phenomenon in insects. The data furthermore suggest that the known efficient thermoregulatory ability of social insect colonies may not successfully buffer the effect of global warming. Head width, body mass, forewing length, and wing area of the social wasp Dolichovespula sylvestris decreased over the last century in the Iberian Peninsula. Wasp wing size decreased over time with a steeper slope compared with body size. The observed morphological changes were related to global warming (increase in mean annual temperature recorded for the study period in the area).