HOTBEE

Bee populations have been declining worldwide over the last century. The drivers of these declines are relatively well identified and include habitat loss, agricultural intensification, parasites and diseases, and climate change. Among all these factors, the potential effects of climate change are arguably the least explored.

In this project, we will study the effects of climate change, alone and in combination with other stressors, on solitary bees. We will focus on solitary bees because, although they comprise the majority of the more than 20,000 bee species worldwide, they have received much less attention than social species. Climate change may affect bees directly, for example by altering their phenology and their life cycle or by changing their distribution ranges, but also indirectly by disrupting their interactions with plants and other organisms such as natural enemies.

In this project we will follow an ecophysiological approach to study the effects of simulated climate change scenarios on development, wintering and emergence in the laboratory. We will monitor metabolic rates and diapause development and assess developmental mortality, body size and phenology. To understand how life history traits affect responses to climate change, we will work with a selected group of species encompassing different life cycle traits and nesting behaviours.

We will also conduct semi-field experiments with individually marked females to assess the effects of climate change scenarios in combination with other stressors (nutrition and pesticide exposure) on reproductive success and population dynamics.

Finally, we will use long-term historical field data to assess compositional changes in a bee-wasp community and their interactions with natural enemies (nest associates).

Our general objectives are:

1. To assess the effects of realistic warming scenarios on the life cycle and phenology of solitary bee species with different life history traits;
2. To assess the effects of climate in combination with other stress factors on individual reproductive success and population dynamics;
3. To analyse the effects of climate change on the composition of a bee/wasp community and their antagonistic interactions with nest associates.