The neurosecretory cells are responsible in insects for the coordination and control of bodily functions such as feeding, metabolism, excretion, reproduction, and development. They do this by releasing substances called neurohormones into the body fluids. Many insecticides have been shown to have neurophysiological and potentially lethal effects upon neurosecretory cells. Many of the neurohormones are peptides, some similar to, if not identical with, peptides produced by nerve cells in vertebrates. It is possible that peptides unique to insects could be exploited for the development and production of safer and more specifically acting insecticides. Decrease in profits is now a major concern to UK cereal farmers confronted with grain surpluses and tightening quality standards. Consequently, interest in alternative combinable crops is increasing, encouraged by EEC subsidies designed to stimulate production of protein- and oil-rich crops. Oilseed rape is already established as the leading cereal break crop, but grain legumes such as combining peas and faba beans are re-emerging as important components of UK crop rotations.