The regulation of the female sex pheromone production, calling behaviour and release is regulated directly and indirectly by the corpora allata and juvenile hormone. Smith and Schal came to this conclusion because both pheromone production and calling failed to occur after allatectomy; both pheromone production and calling could be restored by a corpora allata implantation or treatment with juvenile hormones; applications of a juvenile hormones to intact females advanced the age of pheromone production and NCA-I "transection", which activates the copora allata in other cockroaches, advanced the age of pheromone production and calling.