Traits influencing plant quality as food and/or shelter for herbivores may change during plant ontogeny, and as a consequence, influence the amount of herbivory that plants receive as they develop. In this study, differences in herbivore density and herbivory were evaluated for two ontogenetic stages of the tropical tree Casearia nitida. To assess plant ontogenetic differences in foliage quality as food for herbivores, nutritional and defensive traits were evaluated in saplings and reproductive trees. Predatory arthropods were quantified and the foraging preferences of a parasitoid wasp of the genus Zacremnops were assessed. In addition, survival rates of lepidopteran herbivores (Geometridae) were evaluated experimentally. Herbivore density was three times higher and herbivory was 66% greater in saplings than in reproductive trees. Accordingly, concentrations of total foliar phenolics were higher in reproductive trees than in saplings, whereas leaf toughness, water and nitrogen concentration did not vary between ontogenetic stages. Survival rates of lepidopteran larvae exposed to natural enemies were equivalent in reproductive trees and saplings. Given the greater herbivore density on saplings, equal survival rates implied a greater foraging effort of predators on reproductive trees. Furthermore, observed foraging of parasitoid wasps was restricted to reproductive trees. I propose that herbivore density, and as a consequence, leaf damage were lower in reproductive trees than in saplings due to both traits influencing food quality, and architectural or unmeasured indirect defensive traits influencing foraging preference of natural enemies of herbivores. Arthropoda : Predator Insecta : Prey Geometridae (Geometroidea) : Host, Prey Zacremnops (Braconidae) : Parasite Nutrition; Diet; Prey; Feeding behaviour; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Population dynamics; Land zones; Nearctic region; North America Arthropoda; Insect prey; Predatory preferences; effects of ontogenetic changes in plant traits; herbivorous taxa; Mexico; Food preferences; For herbivorous insect prey; responses to ontogenetic changes in plant traits; Foraging preferences; Foraging Geometridae; Food plants; Herbivorous attack; influences of ontogenetic changes in plant traits; Mexico; Casearia nitida; Hymenopteran parasites; Zacremnops; Survival; Survival rates; Predators; Arthropoda Insecta; Food plants; Herbivorous attack; influence of ontogenetic variation in foliage quality & plant architecture; Casearia nitida; Population density; Predators; Predatory preferences; effects of ontogenetic changes in plant traits; herbivorous taxa; Arthropoda; Mexico; Jalisco, Estacion de Biologia Chamela Zacremnops; Foraging; Foraging preferences; Lepidopteran hosts; Parasitoid foraging preferences; responses to ontogenetic changes in plant traits; Mexico; Geometridae none not entered