Herbivore-induced plants responses can affect the preference and performance of herbivores and their natural enemies. These responses may vary depending on the identity and number of herbivore species feeding on the plant so that when herbivores from different guilds feed on plants, the interactions between plants, herbivores, and natural enemies may be disrupted. Tomato plants were damaged either by the caterpillar Spodoptera exigua, or the aphid Macrosiphum euphorbiae, or damaged by both herbivores, or undamaged controls. We measured the preference and performance of S. exigua and its parasitoid Cotesia marginiventris, and activity of proteinase inhibitors (PI) as an indicator of induced resistance. Compared to undamaged plants, caterpillar damage reduced the number of eggs laid by S. exigua adults, reduced growth, consumption, and survival of larval S. exigua and C. marginiventris, and increased activity of PIs 43%; but did not increase attraction of C. marginiventris. While pupal mass of S. exigua was not affected, the pupal mass of C. marginiventris decreased on caterpillar-damaged plants compared to controls. In contrast, plants damaged by aphids were preferred for oviposition by S. exigua, and had increased larval consumption and survival, compared to controls. Aphid feeding did not affect the preference or performance of C. marginiventris, or PI activity, compared to controls. While oviposition was deterred on caterpillar-damaged plants, plants damaged by both herbivores received the same amount of oviposition as controls. The attraction of C. marginiventris to plants damaged by caterpillars and aphids was increased compared to controls. However, plants damaged by both herbivores had similar PI activity, larval growth and survival of S. exigua and C. marginiventris, as plants singly damaged by caterpillars. Overall, the preference component for both the herbivore and parasitoid was more strongly affected by damage due to multiple herbivores than the performance component. Spodoptera exigua (Noctuidae) : Host Cotesia marginiventris (Braconidae) : Parasite Macrosiphum euphorbiae (Aphidoidea) : Parasite Biometrics; Nutrition; Diet; Reproduction; Reproductive productivity; Life cycle and development; Development; Growth; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Ecology; Population dynamics Cotesia marginiventris; Weight; Lepidopteran hosts; Host & parasite performance; differential effects of induced plant responses to multiple damagers; Spodoptera exigua; Survival Macrosiphum euphorbiae; Plant hosts; Host induced responses effect on lepidopteran herbivore & hymenopteran parasitoid performance; Tomato Spodoptera exigua; Weight; Food plants; Single & multiple herbivore induced plant responses effects on performance & hymenopteran parasites; Tomato; Feeding rate; Food consumption; Egg number; Growth rate; Hymenopteran parasites; Cotesia marginiventris; Survival none