RESUMO
Plant defenses are plastic when a single genotype can produce different phenotypes depending upon the environment. Plastic responses might be favored by selection only if plants can respond appropriately to reliable information in their environments. Recent findings indicate that when information is accurate, plants can benefit by changing their defenses appropriately but, when information is inaccurate they produce inappropriate defenses and have lower fitness. Plants can potentially use a variety of cues to adjust their defensive phenotypes appropriately. The relationship between the information about risk of herbivory and plant defense can be evaluated by determining if the information available to plants is reliable enough to support the evolution of plastic-induced defenses.