I use ecological stoichiometry to study the limitations imposed on organisms due to mismatches between their nutritional demands and the supply of nutrients in their environment. My work focuses on two examples of herbivore life histories shaped by the stoichiometries of their food, representing the extremes of feeding strategies: (1) nutrient-deficient dead wood exploited by xylophages and (2) nutrient-rich pollen used by bees. My current research activities concern sexual dimorphism in the nutritional needs of bees and the effects of taxonomically diverse floral resources on bees.