Statistical studies using the randomised complete block design with four replicates showed that volatile extracts of two species of orange peel - Citrus sinensis (sweet orange) and Citrus aurantifolia (lime) had insecticidal activity against mosquito, cockroach and housefly. Insecticidal activity was better after 60 min than at 30 min spraying of rooms. Volatile extracts of C. sinensis showed greater insecticidal potency, while the cockroach was the most susceptible to the orange peels among the three insects studied. (C) 2000 Elsevier Science Ltd. All rights reserved.