Male antennae of Cadra cautella, Pectinophora gossypiella, and Spodoptera exigua were presented with 20-ms-duration pulses of their two-component pheromone at rates of 1 to 33 Hz. Fourier analyses of electroantennograms resolved the temporal structure of trains of pheromone filaments delivered at up to 33 Hz for C. cautella and S. exigua and 25 Hz for P. gossypiella. Pheromone components tested separately for each species were generally equivalent in filament resolution to complete blends. Ambient temperatures of 18, 23 and 28 degrees C affected filament resolution only slightly, with poorer ability to discriminate rapidly pulsed signals at 18 degrees C. The question of how, or indeed if, such frequencies are conserved beyond the peripheral nervous system, remains.