Haemoproteomics of Bombus terrestris following pesticide exposure and interaction with Crithidia bombi

Pesticides pose a potential threat to bee health, especially in combination with other stressors, like parasites. However, pesticide risk assessment tests them in isolation from other stresses. We tested acute oral doses of three pesticides - glyphosate, Amistar and sulfoxaflor - on the bumblebee, Bombus terrestris, alongside the gut parasite Crithidia bombi. We found no impact of any pesticide on parasite intensity and no impact of sulfoxaflor or glyphosate on survival or weight change. Amistar caused weight loss and 19-41% mortality. Haemoproteome analysis showed various protein dysregulations. The major pathways dysregulated are those involved in insect defences and immune responses, with Amistar having the strongest impact on these. Our results show that while no response can be seen at a whole organism level, MALDI BeeTyping® can detect effects. Mass spectrometry analysis of bee haemolymph represent a pertinent tool to evaluate the stressor impacts on bee health, even at the individual scale. Through molecular analysis, specific impacts of a pesticide, or its interaction with another stressor can be elucidated. Molecular mass profiling by MALDI BeeTyping® was used on bee haemolymph to explore the signature of pesticidal and parasitic stressors impacts. This approach was complemented by Bottom-up proteomics to investigate the haemoproteome modulation.