The broader use of botanical pesticides has been limited by shorter residual activity on plants, slower onset of action, and higher costs compared with conventional pesticides. These challenges could be overcome by the development of simple, cost-effective, and long-lasting preventive nanocomposites for botanical pesticides. In this study, we successfully developed a low-cost ethyl cellulose (EC)-based delivery system for the botanical pesticide osthole (OST), designed to provide extended preventive protection against