DISCRIMINATION AMONG PHEROMONE COMPONENT BLENDS BY INTERNEURONS IN MALE ANTENNAL LOBES OF 2 POPULATIONS OF THE TURNIP MOTH, AGROTIS-SEGETUM

A difference in female pheromone production and male behavioral respon se has previously been found in two populations of the turnip moth, Ag rotis segetum, originating from Sweden and Zimbabwe, respectively. In this study, rye investigated the pheromone response of antennal lobe i nterneurons of mates of the two populations by intracellular recording s, stimulating with single pheromone components and various inter- and intra-populational pheromone blends. Three major physiological types of antennal lobe neurons were established in the two populations accor ding to their responses to different stimuli. One type responded broad ly to almost all the stimuli tested, The second type responded selecti vely to some of the single components and blends, The third type did n ot respond to any single components but did respond to certain blends, Furthermore, some neurons of the second and third type recognized str ain specific differences in ratios between pheromone components. Both projection neurons and local interneurons were found among these three types. Two pheromone responding bilateral projection neurons are repo rted for the first time in this paper.