Abstract
Sexual attrction of Rotylenchulus reniformis females was tested on agar plates and their attractiveness was compared among three amphimictic populations and three parthenogenetic ones, which were originally collected at geographically isolated areas. Females of the amphimictic populations attracted males of an amphimictic one better than the females of the parthenogenetic ones. Stimuli evoking males to respond were assumed to be secreted by females into the agar, and to be chemical in nature. Most of the males attracted to the amphimictic females copulated with or remained close of the females for a long period, whereas males attracted to the parthenogenetic females did not behave similarly. Tracks left on the agar by males showed frequent sudden changes of direction when attracted to the amphimictics but showed no such changes when placed with the parthenogenetics. A reproductive isolation between the amphimictic and the parthenogenetic populations was suggested.
