Final instars reach 30-40 mm in length. The body is smooth and shiny, variable in colour but typically creamy white with a pinky shading. The head and prothoracic plate are brown and the anal plate is yellowy-brown.
Spiracles are elongate oval with black surrounds.
Hemispherical, ca. 1 mm in diameter with radial ridges. Creamy white when laid, becoming darker with age. Deposited in small batches between lower leaf sheaths and the stem.
Larvae feed within the stems of their host, forming galleries that become filled with frass. Stem tunnelling kills growing points, results in dead hearts and also causes stem breakage. On maize larvae also feed in maize cobs.
