• The eggs are laid on leaves.
• After hatching from the egg yellowish maggots bore the nearest vein of the leaf.
• The maggot then reach the stem through petiole and bore down the stem.
• If the infected stem is opened by splitting, distinct zig zag reddish tunnel can be seen with maggot or pupae inside it.
• The maggots feed on cortical layers of the stem, may extend to tap root, killing of the plant.

Identification of the pest

• Maggot : White in colour and remains inside the stem.
• Adult : Flies are shining black and about 2 mm long.

• Deep summer ploughing.
• Avoid pre monsoon sowing.
• Use optimum seed rate and plant spacing.
• Proper crop rotation with dissimilar crops should be followed.
• Remove and destroy the damaged plant parts.
• Soil application of @ 30 kg/ha at the time of sowing will prevent early infestation by stem fly.
• One or two sprays of 0.03% or 0.05% quinalphos 25 EC can stop the damage.