Field library

Shoot Borer

Shoot borer is a small caterpillar that attacks maize from the seedling stage onwards. It first scrapes the young rolled leaves, leaving rows of small holes and window-like patches, then bores into the central shoot and kills it, so the middle leaf dries up and pulls out easily. In older plants it tunnels down inside the stem, which weakens the plant, cuts the cob size, and lets the stalk snap in wind.

How to scout

From about a week after the crop comes up, walk two diagonals across the field twice a week and pull the middle leaf of any plant that looks yellow, stunted or shows shot-holes — if it slides out easily and smells rotten at the base, that plant has shoot borer.