Electrophysiological basis for the behavioural response of male and female Trichoplusia ni to synthetic female pheromone

Electroantennogram (EAG) studies demonstrated that antennae of both male and female Trichoplusia ni have: (1) receptor-neurones sensitive to female pheromone, (2) a low response threshold, (3) an identical mean-percentage EAG curve over a broad concentration range of pheromone, and (4) a similar absolute recovery interval from adaptation to pheromonal stimulation. These factors suggest that antennae of male and female T. ni have homologous and homogeneous acceptor sites for the female pheromone. Pheromonal stimulation of female antennae elicited EAGs with only 25% of the amplitude of those elicited in males.