ABSTRACT
Olfaction is the perception of relatively low concentrations of airborne chemicals by an organism. A differential adaption technique allows a greater insight into the olfactory receptor system of an organism. The olfactory receptors of insects are associated with sensilla located primarily on the antennae. The number of olfactory sensilla present on the antennae is variable even between members of the same insect order. The fine structure of insect sensilla has been the subject of a number of reviews. Laboratory and field bioassays based on behavioral or physiological responses of insects are employed as an indirect means of studying their olfactory processes. Electrophysiological techniques provide a direct means of investigating the function and activity of the olfactory organs. The vast majority of olfactory theorists favor a chemical interaction between the odor molecule and receptor site as providing the necessary activating olfactory stimulus.
