Sugarcane Borer
Diatraea saccharalis (Fabricius)

PLANTS ATTACKED: Sugarcane, corn, grain sorghum, broomcorn, Dallisgrass and Sudangrass.

DESCRIPTION: Adult. The straw-colored moth has black dots arranged in a V-shape on each forewing. The average distance from tip to tip of the wings is 1 inch. The amount of food taken by the larva determines to some extent the size of the moth.

Larva. The full-grown larva is about 1 inch long. It is yellowish with four noticeable brown spots on the dorsal area of each of most of the body segments. The head and prothorax are brown. These markings are absent or faded on the overwintering larva.

LIFE HISTORY: The larva becomes active in the early spring following hibernation within a tunnel in the plant. After extending the tunnel toward the outer surface of the stalk, the larva transforms to a pupa, from which the adult emerges a few days later. The female lays eggs in clusters of 25 to 50 on the leaves of the host. The egg hatches in about 1 week and the tiny worm feeds on the leaves for a short time and bores into the stalk where it feeds within the tunnel until late July. The larva tunnels down to the crown of the stalk and may pupate, but usually it moves out of the plant into the soil for transformation. The adult emerges 2 to 6 weeks later. There is only one generation per year.

DAMAGE: Injury by this insect to corn and other plants is similar to that caused by the southwestern corn borer and the southern cornstalk borer.