ESTERASE-ACTIVITY IN THE OLFACTORY SENSILLA OF THE SILKMOTH ANTHERAEA-POLYPHEMUS

WE studied in individual males of Antheraea polyphemus the activity of the sensillar esterase, a pheromone-degrading enzyme present in the s ensillum lymph surrounding the olfactory receptor cells. In parallel, receptor potentials from single pheromone-sensitive sensilla trichodea were recorded. Our screening revealed a large variability of the enzy me activity in individuals with similar electrophysiological responses . In some moths the sensillar esterase was not detectable, i.e. presen t with 100-fold less activity. However, such variable esterase activit y showed no correlation to the time course of the receptor potential. Thus, enzymatic pheromone degradation does not seem to be involved in the rapid pheromone inactivation at the end of the stimulus, but rathe r serves as the final pheromone sequestration step.