CIRCADIAN-RHYTHM OF SEX-PHEROMONE PERCEPTION IN THE MALE AMERICAN COCKROACH, PERIPLANETA-AMERICANA L

In male American cockroaches, the daily pattern of the response to syn thetic periplanone-B, the main component of the female sex pheromone, was quantitatively assessed. Both the response level, the latency of r esponse, and the dynamic range of doses evoking responses are under ci rcadian control. Saturating doses, which were beyond the physiological range, elicited activity exhibiting a daily rhythm. The circadian sys tem of pheromone perception includes components regulated by endogenou s mechanisms, by daily changes in illumination and temperature, or by both of these factors.