Plant essential oils for pest and disease management

Certain essential plant oils, widely used as fragrances and flavors in the perfume and food industries, have long been reputed to repel insects. Recen t investigations in several countries confirm that some plant essential oil s not only repel insects, but have contact and fumigant insecticidal action s against specific pests, and fungicidal actions against some important pla nt pathogens. As part of an effort aimed at the development of reduced-risk pesticides based on plant essential oils, toxic and sublethal effects of s ome essential oil terpenes and phenols have been investigated using the tob acco cutworm (Spodoptera litura) and the green peach aphid (Myzus persicae) as model pest species. In this paper I review (i) the range of biological activities of essential oils and their constituents; (ii) their toxicity an d proposed mode-of-action in insects; (iii) their potential health and envi ronmental impacts as crop protectants; and (iv) commercialization of pestic ides based on plant essential oils. (C) 2000 Elsevier Science Ltd. All righ ts reserved.