Identification of chemicals that affect the naturally occurring interactions be tween organisms requires sophisticated chemical techniques, such as those docu mented in volume 1, in combination with effective bioassays. Without an effective bioassay, the identification becomes akin to looking for a needle in a haystack, but without any idea of what a needle looks like. To a large extent serniochemical identifications must be driven by bioassays. The design of bioassays for use in chemical ecology is governed by the sometimes conflicting objectives of ecological relevance and the need for...

A working definition of the discipline of chemical ecology might be "the study of the structure, function, origin, and significance of naturally occurring compounds that mediate inter-and intraspecific interactions between organisms. " In particular, chemical ecology focuses on determining the role of semiochemicals and related compounds in their natural contexts. Thus, chemical ecology is distinct from disciplines such as pharmacology, in which compounds are screened for uses outside their natural context, for example in the screening of natural products for use as drugs. Superficially, many...