It is emphasized in numerous prospective studies that the development of swarms of Unmanned Aerial Vehicules (UAV) should be important in the next years. However, the design of these new multi-agent systems involves to take up many challenges. In particular, reducing the number of operators requires to define new interfaces in order to interact with such autonomous multirobot systems. We present an approach that allows one operator to control a swarm of UAVs in the context of simulated patrolling and pursuit tasks. Self-organized control relying on digital pheromones, as well as authority sharing based on several operating modes are defined. Experiments with human operators on the simulated system show that the combination of the two approaches is effective.