Bean and Pea seed fly (Latin name – Delia platura, Delia florilega)
- Adult fly is very small (3 to 6 mm long) & grey in colour
- Eggs are pearly white, elongated & 1 mm long, laid on the soil surface
- Larva or maggot is white & grows to 8 mm long – feeds on germinating seed
- Pupa are red-brown, & 5 mm.
Damage Caused by Bean and Pea seed fly:
- partial or total failure of seedlings to emerge.
- Seeds often tunnelled and the maggots can be found inside the developing root or stem.
- malformed seedlings due to damaged stem & leaves – if growing centre is damaged the seedling ’snakes’.
Damage is caused by the larvae of the bean/pea seed fly, which develop from eggs laid on the soil surface and feed on the germinating seed. The larvae turn into pupae, which can be found in the soil around the damaged seedlings.
Control of Bean and Pea seed fly:
- Chemical control: use treated seed
- Cultural control:
- use stale seedbed, as the fly lays eggs in freshly disturbed soil.
- soils high in organic matter also attract flies
- avoid soil with dead vegetation as maggots are scavengers & flies are attracted to vegetable matter
- do not plant seed too deep
Bean and Pea seed fly can cause severe damage to peas and beans in the garden, but the severity of attack depends on the season.