Global warming impairs the chemical attractiveness to pollinators

Abstract Global warming is expected to impact the chemical communication between flowering plants and their pollinators. Here, we aimed to test by chemical analytical, electrophysiological, and behavioral approaches whether temperature-induced shifts in floral scent of strawberry (Fragaria x ananassa) affect chemical communication with its main bee pollinators (Apis mellifera, Bombus terrestris, Osmia bicornis). While strawberry flowers in the optimum scenario released 10.4 ng/flower/hour, mainly p-anisaldehyde (81%) and seven other scent compounds, in the warmer scenario, the flowers did not emit any detectable scent. In the behavioral experiments, the pollinators were attracted by the scents of the optimum scenario. We predict that the absence of detectable scent emissions from strawberry plants grown under heat stress will drastically reduce the attractiveness of the flowers to the pollinators. Our study raises important ecological and agricultural questions, as decreased attractiveness of flowers to pollinators might result in insufficient pollination with negative consequences for ecosystem functioning and crop yields.