Spotted Bollworm in cotton management (Pest characters, Nature of Damage and Control Measure)
Scientific name: Earias vittella.
Pest Characters of Spotted Bollworm in cotton
• The moths are tiny.
• The hind wing of both species is white.
• Broad, green, tripe across the length of the fore wing.
Nature of Damage of Spotted Bollworm in cotton
They lay eggs singly on shoots, small leaf, flowers bud and plant tops. Egg hatch between 4-5 days, newly hatched caterpillars enter into the growing shoot and feed inside the vascular bundle and check translocation of food. Affected shoot wither and die, at the later stage of the plant they enter either into the flowers bud or into the green boll.
When flower buds are infested due to the feeding their inside, a characteristics symptom is produced called “flared squire” afterward fall down.
When green bolls are infested firstly, the hole of the entry closes down but the larvae feeding inside the seed kernel. The attacked boll falls down prematurely which grows mature and does not contain good lint and the seeds oil content is reduced.
Control Measure/Management of Spotted Bollworm in cotton
1. Field sanitation after harvest.
2. Avoid the use of nitrogen fertilizers at the reproductive stage.
3. Early sowing and early harvesting.
4. Use resistant varieties.
5. Collection and destruction of infested bolls.
6. Release egg parasitoid Trichogramma chilonis, T. brasiliensis, and larval parasitoids Chelonus blackburnior Bracon brevicornis or Apanteles sp. at 35 to 70 days.
7. Using systemic insecticides. e.g. Diazinon 60 EC @ 1.68 L/ha, Ripcord/ Cymbush/ Fenon @ 1.2 L/ha.
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