The study deals with the chemical mechanisms by which insects interact with organisms in their environment. It is aimed at elucidating the chemical structure and biological function of substances that insects use for defense against enemies, communication with mates, and protection of offspring. Molecular characterization will be effected by modern analytical techniques (GC- and HPL-chromatography; mass-and nuclear- magnetic spectrometry); biological studies will involve field and laboratory bioassay, structural and ultrastructural studies of glands, and various techniques for elucidation of physiological functions. Insects are major vectors of disease. An understanding of how insects depend on natural products for regulation of their biotic interactions is of broad applied significance to both medicine and agriculture.