The roles of mating, grouping with conspecific individuals, and exposure to conspecific odors were investigated using the onset of calling behavior (pheromone release) and oocyte development as indirect measures of corpus allatum activity. For any given age in the first gonadotrophic cycle, oocyte size at the onset of calling in virgin females was smaller than that at the onset of mating receptivity. Isolation had no significant effect on either calling or oocyte growth in virgin females. However, females grouped with normal males (i.e., mated) exhibited accelerated gonadotrophic cycles compared with females grouped with phallomerectomized males (i.e., unmated). Thus, copulation accelerates corpus allatum activity and oocyte maturation. The onset of calling and its diel periodicity were advanced in females housed with other virgin females relative to females housed with either mated females or with phallomerectomized males. The importance of experimental design in studies of extrinsic factors that affect endocrine-mediated events is discussed.