Chemical identification of two compounds in bed bug (Cimex lectularius) fecal extracts which elicit off-host aggregation

After feeding, bed bugs aggregate in cracks and crevices near potential hosts.  Aggregation is mediated by tactile stimuli and an aggregation pheromone associated with the bugs’ feces.  Crude extracts collected from fecal stained papers were analyzed by gas chromatography coupled with an electro-antennogram detector (GC-EAD).  Adult antennae responded to compounds associated with five elution regions of the crude extract.  The extracts were then analyzed by gas chromatography with a mass spectrometer detector (GC/MSD) to identify chemical compounds associated with the specific regions of interest.  Several chemical compounds were identified in each of the regions, and select compounds were evaluated in multiple choice assays to assess aggregation response.  A combination of two compounds, dimethyl trisulfide (DMTS) and methyldiethanolamine (MDEA) resulted in aggregation responses equivalent to the original extract.