Odours play a very important role in the life of insects belonging to
the order Lepidoptera. In the present paper, a review is given of the
current knowledge of morphology, development and function of the olfac
tory system in larval and adult moths and butterflies. Research regard
ing both the antennal and accessory olfactory pathways, as well as bot
h the pheromone and the host odour detecting systems, is reviewed.