Aerosol Alteration of Behavioral Response to Pheromone in Bombyx mori

Because of the complexity to study them, aerosols have been neglected in nearly all studies on olfaction, especially studies dealing with odor capture. However, aerosols are present in large quantities in the atmosphere and have the physico-chemical ability to interact with odor molecules, in particular the many pheromones with low volatility. We submitted male moths of Bombyx mori to bombykol puffs, the main fatty alcohol component of its sex pheromone, depending on whether the air is free of aerosols, charged with ambient concentration aerosols or supplemented with aqueous aerosols and recorded their arousal behavior. Aerosols and pheromone do interact consistently over all experiments and moths react better in low aerosol-concentration conditions. We propose four hypotheses for explaining this impediment, the two most likely resorting to competition between odor molecules and aerosols for the olfactory pores and postulate a reversal to a positive impact of aerosols on communication, depending on the particular physico-chemical properties of the multiphasic interaction. Studying the partitioning between gas and particulate phases in the transport and reception of odors is key for advancing the chemico-physical understanding of olfaction.