All known host plants contain natural chemicals called glucosinolates, that are cues for egg laying. Host plants are: herb Cruciferae – "Arabis glabra", "Armoracia lapthifolia", "Armoracia aquatica", "Barbarea vulgaris", "Barbarea orthoceras", "Barbarea verna", "Brassica oleracea", "Brassica rapa", "Brassica caulorapa", "Brassica napus", "Brassica juncea", "Brassica hirta", "Brassica nigra", "Brassica tula", "Cardaria draba", "Capsella bursa-pastoris" (females oviposit but larvae refuse it), "Dentaria diphylla", "Descurainia Sophia", "Eruca sativa", "Erysimum perenne", "Ipomoea alba", "Lobularia maritima", "Lunaria annua" (retards larval growth), "Matthiola incana", "Nasturtium officinale", "Raphanus sativus", "Raphanus raphanistrum", "Rorippa curvisiliqua", "Rorippa islandica", "Sisymbrium irio", "Sisymbrium altissimum", "Sisymbrium officinale" (and var. "leicocarpum"), "Streptanthus tortuosus", "Thlaspi arvense" (larvae grow slowly or refuse it); Capparidaceae: "Cleome serrulata", "Capparis sandwichiana"; Tropaeolaceae: "Tropaeolum majus"; Resedaceae: "Reseda odorata".