Abstract
Females of the free-living dioecious nematode Panagrellus silusiae that have undergone postembryonic development in hydroxyurea do not attract males, and treated males do not respond to normal females. Nematodes placed in hydroxyurea as adults have normal gonads and retain the sexual attraction system. Hydroxyurea has no effect upon copulatory behavior of adult animals. Treatment of adult females with actidione stops production of attractant, although production resumes within 24 h after removal of the females from actidione. Actidione treatment of males has no effect upon the response to attractant by males or on copulation. It is proposed that sexual attraction depends on complete development of the reproductive system, but that copulation does not.