Bumblebee Haemolymph Proteome Response to Pesticides and Parasites

This study examines the molecular effects of pesticides—Amistar, glyphosate, and sulfoxaflor—and the gut parasite Crithidia bombi on the haemolymph proteome of bumblebees (Bombus terrestris). Using MALDI BeeTyping® and bottom-up proteomics, it reveals that Amistar causes significant mortality, weight loss, and immune system activation, with upregulation of apidaecin, chymotrypsin inhibitor, and neutrophil degranulation pathways. Glyphosate and sulfoxaflor show minimal whole-organism effects, but proteomic analysis detects differential expression of 65 proteins after Amistar exposure, primarily affecting carbohydrate metabolism, lipid transport, and proteolysis. Sulfoxaflor induces over 50% up-regulation of defence-related proteins. C. bombi alone has negligible impact on haemolymph composition. PCA and Cytoscape network analyses confirm distinct molecular fingerprints per treatment, highlighting that mass spectrometry detects sublethal stressor effects missed by traditional assays. The study underscores the value of haemolymph proteomics for early risk assessment of agrochemicals and identifies Amistar as a major disruptor of bee immune and metabolic pathways.