Dr. Elizabeth Bernays of the University of California, Berkeley, intends to establish, in a varied group of insects, whether or not behavioral rejection of plants is correlated with oral toxicity (including any adverse effects on fitness) of such plants. The question has never been specifically addressed, but preliminary data suggest that correlation of deterrence with "toxicity" for plant secondary compounds is poor. If this proves to be generally true, it must be asked why behavioral deterrence is so widespread. The selective forces maintaining host plant specificity the associated rejection of most plants could well be more positive needs based on quite different principles. In that case, our understanding of plant defenses against insects would need revision. These researches bear directly on questions of pest control and parasitism in agriculture and agroforestry which could have wide ranging connotations, especially in tropical systems. The investigator and her institution are well suited to pursue this research to a successful conclusion.