The larvae live in the stems of Pfragmites communis and especially Arundo donax, rarely probably also in other grasses with thick stems.
Sesamia nonagrioides inhabits barrancos (Canaries), wetlands and other places with the host plants.
The adults are on the wing usually all year round. The larvae live in the stems and reveal themselves through holes and dying inner leaves. Pupation takes place at least partially also in the stems (head on the top) as some own observations show.
Sesamia nonagrioides has a subtropical distribution and is found in the Mediterranean, in parts of Africa and more southerly Asia and in parts of Macaronesia (e.g. Canaries and Madeira).