none The Comoro Islands, maize crops are severely attacked by a stem borer, Chilo partellus, present here without its usual suite of mass as in the African continent. This led IRAT to attempt to introduce entomophagous as part of a maize project supported by the FED in the Comoro Islands. The authors report the rearing of 5 hymenoptera as parasites, their release in maize crops, and the results of these tests. From 1981 to 1983, 2,800,000 Tetrastichus atriclavus, 6,300,000 Trichospilus diatraeae, 411,000 Apanteles flavipes, 100,000 Trichogramma confusum, 112,000 T. evanescens and 834,000 T. nagarkatii were released. Though due precautions were taken to ensure a good transport, to maintain insects in good conditions for their release and to release them in different sites, none of them get acclimatized and could breed over more than 1 to 2 generation after releases. The failure can be attributed to the small amount of C. partellus present in the cold season and the incapability of the introduced parasites of exceeding this period. The authors think that introductions could be made again by looking for parasites able to survive in their host in quiescence or winter diapause conditions. It would also be advisable to study to what extent massive releases of Trichogramma nagarkatii might be a feasible and efficient method, when associated or not with a biological insecticide.