SPATIAL-ORGANIZATION OF OLFACTORY RECEPTOR NEURONS ON THE ANTENNA OF THE CABBAGE-LOOPER MOTH

Electrophysiological responses to stimulation with behaviorally releva nt compounds were recorded from receptor neurons within specialized cl asses of sensilla on the antennae of male cabbage looper moths. Recept or neurons were found that specifically respond to stimulation with Z- 7,12:AC, Z-7,14:AC: Z-9,14:AC, and Z-7,12:OH. Specialized receptor neu rons were not found for the three remaining pheromone blend components , 12:AC, Z-5,12:AC, or 11,12:AC. However, a new class of sensillum con taining a pair of neurons insensitive to all of the cabbage looper phe romone components was encountered. In addition, spatial patterns of di stribution along the flagellum for identified classes of sensilla are described. Sensilla containing Z-7,12:AC-sensitive neurons are prefere ntially located on the proximal half of the antennal flagellum. In add ition to this distribution along the length of the antenna, a pattern across individual flagellar subsegments is described. Sensilla contain ing neurons sensitive to Z-9,14:AC were found exclusively on the later al margins of individual flagellar subsegments.