Abstract
This communication reviews recent biochemical studies ofl-canavanine that have provided significant understanding of the interaction between the seed ofDioclea megacarpa (Leguminosae) and the bruchid beetleCaryedes brasiliensis (Bruchidae). The principal biochemical bases are proposed for: canavanine toxicity, the ability of the beetle larvae to adapt to its presence, the metabolic sequestration and detoxification of ammonia, and the potential amplification by microbial symbionts of the beetle's abilities to adapt to toxic components of the host.