Pest:Stem fly

Ophiomyia phaseoli

Agromyzidae

Adult is a small fly with a wing length of 20 mm. Body is dark with pubescence. Eggs are laid in cavities of leaves or stem made by the female flies. The fly feeds on the juice exuding from oviposition wounds. About 14-64 eggs are laid. Egg period lasts for 2-4 days. The maggots mine the leaves and bore in to leaf petiole or tender stem. Larval period lasts for 6-10 days. Pupation takes place inside the larval gallery for a period of 1-3 weeks.

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Symptoms

  • As a result of maggots boring into the stem the plant withers, droop and dies.
  • The damage is more severe in seedlings than in grown up plants.
  • The adults also cause damage by puncturing leaves.
  • The injured regions turn yellow.
  • Attack on the seedlings result in the reduction in the stand of the crop.

Procedure for Observation

Subject the young stages of the crop to observation. Look for the damage. Collect adults by making ten sweeps.

ETL

  • Five adults per sweeps.

    • Control Measures

  • Spray Hyptis suaveolens extract plus soap solution diluted in water. This is very effective in managing the adults.
  • Spray tobacco decoction (one liter of the prepared decoction to be diluted in six liters of water) or neem seed kernel extract 5% or 2% neem seed oil emulsion plus garlic extract.
  • Spray 3 % urea solution to improve stand of the crop.
  • Insecticidal control can be obtained by spraying acephate (Asataf 75 SP/ Starthene 75 SP) or imidacloprid (Confidor 200 SL/Tatamida 200 SL).