Chemical Ecology Of Bed Bugs (Heteroptera: Cimicidae) In Their Microhabitats

Abstract:
Extracts of the exuviae of nymphal bed bugs (Cimex lectularius) were analysed for volatile compounds that might contribute to arrestment of adult bed bugs. Four volatile aldehydes, (E)-2-hexenal, 4-oxo-(E)-2-hexenal, (E)-2-octenal, and 4-oxo-(E)-2-octenal were consistently detected in the headspace of freshly shed exuviae. Quantification of the aldehydes in the solvent extracts of homogenized exuviae with varying aging periods indicated that the aldehydes are originally present in the exuviae and dissipate over time, possibly through evaporation. Microscopic observation of the exuviae indicated that the dorsal abdominal glands on the exuviae maintained their reservoirs, within which the aldehydes might be retained. Two-choice olfactometer studies with the volatiles from exuviae or a synthetic blend mimicking the volatiles indicated that adult bed bugs tend to settle close to sources of the aldehydes. Our results imply that the presence and accumulation of bed bug exuviae and the aldehydes volatilizing from the exuviae might mediate bed bugs’ interaction with their microhabitats. Some recent studies on the potential functions of the volatile aldehydes within microhabitats of bed bugs are discussed.