Sex pheromone communication in the nematode,Rhabditis pellio

Both males and females ofRhabditis pellio release pheromones that attract the opposite sex prior to copulation. A quantitative bioassay for the female-produced pheromone was designed, based on male movement toward a pheromone source placed at one end of a 10-mm strip of bacterial material maintained on nutrient agar in a petri plate. Females produced pheromone from the age at which they attained the adult stage (3 days following hatching from the egg) and maintained a relatively constant production level until at least the ninth day of life. Similarly, males became responsive to the female pheromone by the third day and remained responsive through the ninth day, although the time required for the males to migrate toward a female pheromone source increased with increasing age. No daily rhythm of pheromone responsiveness by males or pheromone production by females was observed when the nematodes were conditioned to a 1212 h light-dark cycle.