Whorl maggot: Hydrellia sasakii
Symptom of damage:
- Maggot feeds on the tender tissue inside the whorl
- Yellowish white longitudinal marginal blotching with hole
- Leaves shrivelled plant stunted and maturity delayed
- Drooping of young leaves near the tip
Identification of the pest:
- Egg: White, cigar-shaped egg laid singly on either side of the leaves
- Grub: Newly hatched larva is transparent to very light cream in colour but later become yellow. The larvae move down the leaf into the whorl on a film of dew and feed within developing whorls. The larvae mostly remain outside the leaves and feed on the mesophyll tissue of the foliage. When leaves emerge from the whorl damage can be seen as pinholes in the leaves and white and yellowish lesions on the leaf edge.
- Pupa: Pupation takes place in between the leaf sheath where the pupa is loosely attached to the stem. The puparium is light to dark brown ovoid and subcylindrical in shape.
- Adult: Adult dark grey flies, 1.8-2.3 mm in size
ETL: 25% damaged leaves
- Remove the alternate hosts and adjust the time of planting (early)
- Optimum recommendation of potash fertiliser
- Spray any one of the followings
- Cartap Hydrochloride 4% G 18750-25000 g/ha
- Chlorpyriphos 20% EC 1250 ml/ha
- Fipronil 5% SC 1000-1500 g/ha
- Fipronil 0.3% GR 16670-25000 g/ha
- Phosalone 35% EC 1428 ml/ha
- TNAU Agritech Portal.