Abstract
NormalDrosophila melanogaster males rapidly react to changes in the mobility of mutantshibire ts females by performing less courtship when the females are paralyzed and by courting movingshibire ts females vigorously. Mutantoptomotor-blind males, which are unable to respond to certain horizontally moving patterns, sustain abnormally short courtship bouts when tested with normal females, almost never perform orientation, one of the courtship behaviors, and require more time to initiate copulation than normal males. These results suggest that males must perceive female movement to perform normal courtship and copulation. Normal females become stationary before copulation occurs. Normal males mate quickly in response to this change in female behavior, while blind males require more time to effect copulation, prolonging the time that the female remains stationary. Mutantsmellblind females, which do not respond to certain odors, continue to move during the time that they are courted by normal or blind males and also require more time to copulate, suggesting that females may stop moving before mating in response to olfactory cues.