Range: N. Africa, Europe, Middle East and Asia to Himalayas. Naturalised in Chile. Flight Period: Polyvoltine. March/Late October. Powerful migrant. Habitat: Diverse. Most habitat types containing Larval Host Plants (LHP) and an adequate supply of robust, nectar-rich plants. Commonly thistles and knapweed. Larval host plant: Brassica, Capparis spinosa (Capparacceae), Tropaeolum majus (Tropaeolaceae). A frequent pest on T. majus and Brassica cultivars. Ova laid in batches and emergent larvae feed as a group outwards thus maximising the damage to the host plants. Larvae have conspicuous warning colours and posess a repellant odour which is derived from the host plant. Larvae are often attacked by the parasite Apanteles spp (Hymenoptera). Hibernates as a pupa.