LAUSR

We have recently shown that the aggregation pheromone of the common bed bug, Cimex lectularius, comprises a six-component blend of dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), (E)-2-hexenal, (E)-2-octenal, 2-hexanone, and histamine. Here, we tested the hypothesis that bed bugs biosynthesize some pheromone components from amino acid precursors in human blood, namely DMDS and DMTS from L-methionine and histamine from histidine. We tested this hypothesis by (i) allowing bed bugs to feed on and metabolize sheep blood enriched with 13C-labelled histidine or 2H-labelled methionine, (ii) extracting bed bug feces (a source of the aggregation pheromone), and (iii) analyzing feces extracts by GC-MS, HPLC-MS and NMR spectroscopy. The analyses revealed that bed bugs converted 2H-methionine to 2H-DMDS and 2H-DMTS, and 13C-histidine to 13C-histamine. There is not enough histidine in human blood to account for the amount of histamine that bed bugs produce and excrete with their feces, and only a small proporti...