Extracts of the leaves of the New Zealand native tree Pseudowintera colorata (Raoul) showed insecticidal and antifeedant activity against the webbing clothes moth, Tineola bisselliella (Hummel), and antifeedant activity against the Australian carpet beetle, Anthrenocerus australis (Hope). Assay-directed fractionation showed that two sesquiterpene dialdehydes, polygodial and 9-deoxymuzigadial, were responsible for these activities. Both compounds had similar antifeedant and insecticidal activity at rates from 3 to 0.4 mg/g wool in bioassays.