[Effect of blood meal on the secretion of pheromone by females of C. nubeculosus (Diptera, Ceratopogonidae) (author's transl)].

In a previous study, we showed that virgin females of C. nubeculosus secrete a sex pheromone which attracts males of the same species and stimulates mating. We consider that a number of physiological factors may be capable of modifying this secretion. In this study, we have investigated the effect of a blood meal on secretion of the pheromone by virgin females. No change in secretion of the pheromone was observed during the blood meal, but a decrease was evident during the next few hours. This decrease continues up to 24 hours after the blood meal, by which time oogenesis has started. At 48 hours after the blood meal, when the eggs are mature, secretion of the pheromone increases. An even more pronounced increase is observed during the period of oviposition, occurring 3 to 4 days after the blood meal. Secretion of the pheromone subsequently diminishes.