Diet-mediated effects of specialized tansy aphids on survival and development of their predators: Is there any benefit of dietary mixing?

► We investigated the effects of diet mixing on generalist aphid predators. ► The aphids were Macrosiphoniella tanacetaria, Metopeurum fuscoviride and Uroleucon tanaceti. ► The suitability of each aphid species is different and affects the fitness of its predator. ► The mixed diet was worse than the best single-aphid diet for Coccinella septempunctata and Chrysoperla carnea. ► The dietary mixing is not always beneficial for generalist predators.