Pest:Epilachna beetle

Henosepilachna septima

Coccinellidae

This is an important pest of bitter gourd and snake gourd. Adult is a hemispherical beetle, reddish brown with black dots on the surface of elytra. Female beetle lays cigar shaped yellowish eggs by thrusting the same on the lower surface of leaves in groups. The grubs on emergence feed by scraping the green matter, become full grown in about two weeks. After a pupal period of 2-5 days the adult emerge. The stages of the pests namely eggs, grubs and pupae are seen on the under surface of the leaves. Adult moves about the plant.

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Symptoms

  • Both the adults and grubs cause damage to leaves by scraping and skeletonizing the leaves.
  • Gradually the leaves dry up.

Procedure for Observation

Select 5 pits at random from the plot. Assess the total number of grubs and pupae from 6 leaves from each pit (For this select 3rd to 8th leaves from the tip of a vine trailing on the pandal) and work out average per leaf. Less than 5 -Mild,5-10 Moderate >10 severe.

ETL

  • Average population including grubs and pupae 2 per leaf.

    • Control Measures

  • Grubs and pupae are often parasitized by the hymenopteran Chrysocharis johnsonii.
  • Collect the stages of insects along with the leaves and transfer them in to perforated poly bags after destroying the eggs.
  • From the parasitized grubs and pupae the parasites will emerge out after some days and they can be released back to the field.
  • Spray caster oil neem oil emulsion plus garlic extract diluted in water.
  • Spray 4-8 % Clerodendron (Fig 216) plant extract or 2-5 % caster seed extract.
  • When insecticide application becomes essential spray quinalphos 25 EC @ 2 ml per lit of water.