• Drooping of the tender leaves and yellowing
• Serious damage of young plants.
• The stem where maggot and pupae are present become swollen and start ribbing.
• Older plants show stunting but are not usually killed.

Identification of the pest

• Eggs: The egg period lasts about 3 days.
• Larva: Larval period lasts for 5-6 days. The larva pupates in the larval groove for 8-9 days.
• Adult: The adult is a small black fly. A female lays 38-79 eggs singly on pods or on flower buds.

Management

• Conserve natural enemies like Euderus lividus , Eurytoma sp., Euderus agromyzae
• Seed pelleting with chlorpyriphos @ 4 ml/kg of seed may reduce stem fly.
• Spray Imidacloprid 70 % WG 500 ml/ha a week after germination and second round 10 days after first round or NSKE 5%
• Timely sowing also minimizes the attack of the pest