A programme for biological control using mass releases of Trichogramma chilonis is currently conducted in the region of Indian Ocean (Réunion Island). This programme which aims at controlling a major sugarcane stemborer, Chilo sacchariphagus (Lep: Crambidae) is based on the new approach to guarantee the success of T. chilonis in the field. This approach includes bionomics studies of different strains of T. chilonis to choose the best candidate, impact of predation (by ants) during the release period, egg laying period of the borer, accessibility to the crop, agronomic practices and crop management. The number of Trichogramma to apply per hectare is also investigated on experimental fields. This project is conducted in partnership with Crop Protection Services and different tests on a larger scale will be planned soon. Regional studies has also been started in Mozambique where C. sacchariphagus is present. The status of Trichogramma spp. in sugar estates has been investigated in cooperation with private sugar companies. (Texte intégral)