Larval host plants of this species include Dracophyllum acerosum, Hoheria glabrata, Hoheria lyallii, Hoheria populnea, Hoheria sexstylosa, Plagianthus regius, Plagianthus betulinus, and Veronica salicifolia. Adult E. undosata feed from the flowers and assist with the pollination of Dracophyllum acerosum and Veronica salicifolia. The larvae of E. undosata have been parasitised by the wasp Meteorus pulchricornis.
