The cultivation of genetically modified maize expressing Bt proteins against Lepidopteran pests poses a risk for non-target (NT) Lepidoptera, particularly for species inhabiting agroecosystems and whose larvae are susceptible to Bt toxins expressed in maize pollen. Here, laboratory studies were conducted to determine the adverse effects of larval exposure to Cry1F pollen (event TC1507) on host plants on two butterfly (Pieris napi, Aglais io) and two moth species (Plutella xylostella, Ematurga atomaria). All NT Lepidoptera tested were affected by the Cry1F toxin in the pollen, albeit in different degrees depending on the species and the recorded parameter. Adverse sublethal effects of increasing Bt pollen concentrations included reduced larval feeding, lower larval body weight and prolonged development times, but no significant effects on adult size or fecundity were observed. Dose-response mortality, measured when all survivors reached adult stage, showed that three species were susceptible to field-realistic pollen concentrations (LC