The Citrus .leaf-miner, Phyllocnistis citrella (Stainton) (Lepidoptera : Gracillariidae) was first detected, in La Reunion in -February 1995. A survey engaged in March-April, showed that the pest was already present in most of the citrus growing areas of the island, from sea-level up to an altitude of 1250 m. Though its native area is asiatic and it is already present in many African countries, this pest showed a clear trend in extending its geographic range in recent years (North and Ceutral America, North Africa and Mediterranean Basin). The large distribution of the pest in La Reunion and its detection in Mauritius soon after indicates that the Mascarenes have probably been contaminated nearly at the same time, by wind-borne insects coming from Asia.The first studies in La Reunion showed the presence of native parasitoids whose impact seemed to increase very quickly and is currently under evaluation. The possibility of using biological control against this pest has been examined. Preliminary studies have also been conducted on integrated control and a first series of selected insecticides has been tested against the pest. Samples of pheromones obtained from Japan showed no attractancy to the males of the strain present in La Reunion.