The Morton Arboretum has reported a borer in a magnolia, Magnolia officinalis var. This moth borer attacks yellow poplar and occasionally other magnolias. It bores in the inner bark, primarily from 2 inches below to 5 inches above the ground line in situations where the bark is damp. It tends to attack trees that are at least 10 inches in diameter.
Heavy infestations can kill the tree.
Full-grown larvae are about 1 inch long. The adult moth is present from May to July. If you notice damage from this insect, please let us know.