Crop Protection :: Oil Seeds :: Pest of Groundnut
Bihar hairy caterpillar: Spilosoma (Diacrisia) obliqua |
Symptoms of damage:
- Young larvae feed gregariously mostly on the under surface of the leaves
- Feed on leaves and causes defoliation
- In severe cases only stems are left behind
Identification of the pest:
- Eggs: Laid in clusters of 50-100 on the lower side of leaves
- Larva: Orange coloured with broad transverse band with tufts of yellow hairs that are dark at both ends
- Pupa: Forms a thin silken cocoon by interwoven shed hairs of the larvae
- Adult: Crimson coloured moth with black dots and a red abdomen. Pinkish wings with numerous black spots
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Management:
- Pre-monsoon deep ploughing (two/three times) will expose the hibernating pupae to sunlight and predatory birds
- Removal and destruction of alternate wild hosts and weeds which harbour the hairy caterpillars
- Mass collection and destruction of eggs and just emerged caterpillars
- Place the twigs and leaves of calotropis, jatropha and papaya around the field to trap grown up caterpillars and destruction
- Grow trap crops like cowpea, castor and jatropha on field bunds to attract the caterpillars
- Conserve the bio control population of spiders, long horned grasshoppers, preying mantids, robber fly, ants, green lace wing, damsel flies/dragon flies, flower bugs, shield bugs, lady bird beetles, ground beetle, predatory cricket, braconids, trichogrammatids, NPV, green muscardine fungus
- Use of NPV (nuclear polyhedrosis virus) on cloudy days at 500 LE/ha will be effective
- Apply safe chemical insecticides at recommended doses only if the insect population crosses the ETL
- Spraying of quinalphos 25 EC (2 ml/lit) or chlorpyriphos 20 EC (2.5 ml/lit) or Dichlorvos 76% EC (2.0 ml/lit) recommended when the caterpillars are younger
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