In laboratory tests, the maximum proportion of oothecae of the oriental cockroach,Blatta orientalisL., parasitized by the evaniid wasp, Prosevania punctata (Brullé), was 51%. Significantly (P<0.05) more 1-d-old oothecae than 28-d-old oothecae, and oriental cockroach oothecae than American cockroach oothecae, were parasitized. In field surveys, the greatest percentage of oriental cockroach oothecae parasitized byP. punctatawas 35%, which decreased as the cockroach infestation level increased. An education program for residents significantly (P<0.05) reduced the percentage of residents who thought the wasps were a problem or killed them. However, 60% of the residents still killed evaniid wasps when they found them.