John A. PICKETT
lACR-Rothamsted, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
The structural nature of semiochemicals, particularly those involving aerial dispersion, is constrained by various physical requirements, often involving low molecular weight and high lipophilicity. Of the routes available for the biosynthesis of such semiochemicals, the isoprenoid pathway probably presents the greatest structural diversity in terms of molecular recognition based on stereochemistry as well as functionality. The role of lower isoprenoids, including newly identified novel structures, is discussed in the context of insect chemical ecology and electrophysiological and behavioural studies, and attempts at strategic use in pest management, are described.