Crop protection in the backyard still relies largely on the use of synthetic pesticides. The use of natural products is slowly gaining acceptance among consumers because of environmental and health concerns. Monoterpenes as well as some sesquiterpenes may be a source for new classes of acaricides and insecticides. These are volatile oils subject to rapid degradation and generally less persistent in the environment than synthetic products. UDA-245 is such an oil. It is extracted from Chenopodium ambrosioides, a North American herbaceous plant. Laboratory studies with adult twospotted spider mite, Tetranychus urticae Koch, showed that a 0.5% concentration of this compound was as effective as insecticidal soap (Safer’s Trounce R ) and significantly better than neem oil. Similar results were also obtained with the European red mite, Panonychus ulmi ( Koch), and it was more effective than abamectin (Avid R). As an insecticide, greenhouse studies showed that a 1.0% concentration was more effective than neem oil against the green peach aphid, Myzus persicae (Sulzer), and western flower thrips, Frankliniella occidentalis (Pergande). It was also very effective against greenhouse whitefly, Trialeurodes vaporariorum (Westwood). At 0.5% concentration UDA-245 had no effect to the parasitoid Encarsia formosa (Gahan).