The response to fire by two eusocial bee species

Abstract

Abstract Fire is a common worldwide disturbance that affected the evolution of life and shaped plant and animal diversity; this is especially applicable in the Mediterranean. In this study, we explore the response to fire of two eusocial bee species of Halictidae, namely, Lasioglossum marginatum (Brullé, 1832) and Lasioglossum malachurum (Kirby, 1802), as to their population number, body size and pollination specialisation. The study was carried out on Chios Island, Greece, during the first 3 years after a wildfire (2013–2015). Fire effect was examined from a spatial viewpoint by comparing unburnt with burnt sites and from a temporal one by comparing populations among different postfire years. We found that L. malachurum populations increased with time after fire, while they were more abundant in the burnt sites during the second postfire year. In contrast, L. marginatum populations decreased in both burnt and unburnt sites, which suggests that the decline was not an effect of the fire alone. Insect body size differed among years for both species, with L. marginatum individuals being smaller in the burnt sites compared to the unburnt, albeit only in the first postfire year. Finally, both species show high partner fidelity but to different plant partners. Our results underscore the importance of studies focusing on the effects of a disturbance at the intraspecific level. However long‐term monitoring is required, especially in the context of the global pollinator crisis and the more frequent and severe wildfires as an effect of climate change.