Busseola fusca (Fuller)


Common name:	Maize Stalk Borer
Ethiopian name:	Ageda Korkur

Order:	Lepidoptera
Family:	Noctuidae

HOSTS:
Main hosts:	Maize, Sorghum
Alternative hosts:	Sugarcane, Many species of grasses and cereals

IMPORTANCE IN ETHIOPIA:
Major pest of:	Maize, Sorghum

DISTRIBUTION IN ETHIOPIA:
	Between 1200 and 2600 meters above sea level, with increasing importance at the higher altitudes.

DAMAGE:
	The leaves of young plants have holes and "windows". When the attack is severe, the central leaves die. In older plants, the caterpillars of the first generation bore in the main stem. Some second generation caterpillars bore in the cobs. Damage to sorghum is usually less serious than damage to maize, because sorghum easily tillers and this can partly compensate for the damage.
	"Shot-holes" and "windows" caused by young caterpillars of stalk borers. "Shot-holes" caused by caterpillars of stalk borers.
INSECT BIOLOGY & RECOGNITION:
Egg:	The eggs are white first, but they turn darker when they get older. They are globular and about 1 mm in diameter. Eggs are laid in a long column stretching up the stem, under a leaf sheath. They hatch after about 10 days.
Larva:	The young larvae are deep purple or black in colour. They crawl up the plant into the funnel. The early stages of the caterpillars feed on the leaves in the funnel of the plant. This results in characteristic lines of holes and "windows". When the attack is severe, the shoot may turn yellow and die. If the plant dies, the caterpillars will move to another plant. If the plant survives, the later stages of the caterpillar will bore into the stem and feed there on the central tissue of the stem. The larval period takes 35 days or more. When fully grown the caterpillars are up to 40 mm long. They have a pinkish white colour and small black spots along the sides of the body. The mature caterpillar cuts a hole in the stem before pupating within the tunnel. Eventually the moth will use this hole to emerge. Stalk borer caterpillar in the stem. Emergence hole in the stem, made by caterpillar of stalk borer.
Pupa:	The pupa is brown and about 25 mm long. The pupal stage of the first generation will last for about 2 weeks. Before the crop ripens there are usually 2 generations. Some of the 2nd generation eggs may be laid on the cob. The caterpillars will feed on the cob, but usually move into the stem when fully grown. Before pupating they will go in a long diapause which lasts until the next rains. Then they prepare a pupal chamber in the stem and pupate.
Adult:	The adult is a pale brown nocturnal moth with a wingspan of 35-40 mm. Busseola fusca. Adult moth, wingspan 39 mm.

	*Caterpillar of Busseola fusca* inside the stem.**

Text adapted from:

INSECT PESTS OF CEREALS IN ETHIOPIA identification and control methods by Hein Bijlmakers, FAO/UNDP Project ETH/86/029 Crop Protection Phase II, Addis Ababa, October 1989