PINK BOLLWORM IN COTTON

PINK BOLLWORM IN COTTON

Telugu name: Gulabi rangu purugu

Scientific Name: Pectinophora gossypiella

Identification of the pest:

Larva

  • Shows colour variation young larva white and late instar almost black, brown or green to pale or pink
  • several dark and light alternating bands running the entire length

Adult

  • Small moth.
  • Forewings arebrown or dull yellow olive grey with dark spots on the forewing.
  • Hind wings margins are deeply fringed.    

Lifecycle:

Destructive Stage: The caterpillar (larva) causes the most damage.

Egg Stage:

The pest lays flat eggs one by one on leaves, flowers, or cotton bolls. The eggs hatch in 4-20 days.

Caterpillar (Larva) Stage:

Young larvae are white in colour and late instar becomes almost black,brown, or green to pale or pink.Larval period lasts for about 25-35 days.

Pupa Stage:

The caterpillars pupate (turn into cocoons) in the soil or crop debris. This stage lasts 8-12 days.

Adult Stage:

The adult is a small moth. Its front wings are brown or dull yellow with dark spots, and the back wings have fringed edges. The moth lives for 7-10 days.

Symptoms:

  • Rosetted flowers
  • The holes of entry plugged by excreta of larvae which are feeding inside the seed kernels.
  • They cut window holes (interlocular burrowing) in the two adjoining seeds thereby forming "double seeds"
  • The attacked buds and immature bolls drop off.
  • Discolored lint and burrowed seeds.

Favourable conditions:

1. Warm Weather: Pink bollworm thrives well in temperatures between 25°C and 35°C.

2. Monocropping: If cotton is grown everyyear continuously without breaks, pests survive easily.

3. Presence of Leftover Crop Debris: Pink bollworm larvae survive in cotton bolls or plant debris from the previous season.

  ETL: 10% infested fruited parts.

Management:

Cultural practices:

  • Sow cotton early (before mid-May) to avoid peak pest attacks.
  • Avoid growing cotton in the same field continuously. Rotate with non-host crops like maize or sorghum.
  • Remove and destroy leftover cotton stalks and bolls after harvest.
  • Plough fields deeply to expose and kill pupae in the soil.
  • Avoid Late Picking  and avoid leaving mature bolls in the field for long.
  • Use pest-resistant or Bt cotton varieties.

Biological control:

  • Use pheromone traps (5-6 traps/acre) to monitor and trap male moths. Replace lures every 3-4 weeks.
  • Spray products like Bacillus thuringiensis (Bt) or neem-based formulations to kill larvae.

Chemical control:

  • Seed treatment with imidacloprid 600 FS@5ml/kg before sowing.
  • Foliar application of chemicals like Emamectin benzoate 5SG @0.25g/l,Thiodicarb@1g/l
  • We can control bollworms effectively by using biopesticide “LARVEX”@250ml/acre.

FAQs:

1. How Pink bollworm is affecting the cotton crop?

Pink bollworm is a destructive pest that damages cotton bolls, reducing yield and fiber quality. If left unchecked it may lead to large financial losses.

2.What  are the symptoms of pinkbollworm infestation in cotton field?

 Rosette flowers,Excreta is visible at the point of boreholes,Entry holes,Discoloured lint and burrowed seeds.

3.What are the susceptible stages for the pink bollwormattack?

 Activity of pink bollworm is more during the flowering and boll formation stages. So,creful management of crop is essential during these critical times.

4.Should I use chemical pesticides for pink bollworm?

 Overuse  of pesticides may lead to resistance. Use pesticides recommended by experts and apply them carefully to avoid harming beneficial insects.For effective control of bollworms use Biopesticide LARVEX.

5. How can I protect my crop next season?

 Destroy leftover cotton stalks after harvest, avoid continuous cotton planting, and monitor fields early for signs of infestation.

 

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