Symptoms

• On foliage: feeding damage on leaves, petioles and stems occurs after larvae have fed on young shoots and leaf axils, this can result in plant wilting and premature plant senescence associated with secondary infection (photos 1 and 2).

• On tubers: more or less superficial galleries and cavities. Cavity walls are often covered with silk threads, blackish frass and larval exuviae (photos 3 to 8).