Pest:Pumpkin Beetles

Aulacophora foveicollis-red

A.lewisii-blue, A.stevensi- grey

Three different coloured beetles are seen on pumpkin,of these the red coloured beetles are more predominant. Female beetles lay eggs singly or in groups in moist soil around the base of plants. The total number of eggs laid by a female is about 300. Egg period is one week. Grub passes 4 instars and become full fed in about 2 weeks. Pupation takes place in soil in a cocoon for a period of one week.

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Symptoms

  • The young grubs ,on hatching bore through the root and gain entry in to the base of the plant and feed, resulting in wilting and drying of plants.
  • The grubs grow by boring in to roots and also stems and leaves which lie on the ground.
  • The adult beetles of these three species feed extensively on leaves flowers and fruits.
  • The feeding holes seen on the leaves of cucurbitaceous vegetable is a characteristic symptom of damage by adult beetles.

Procedure for Observation

For cucurbits which trail on the ground: Make 20 sweeps from the plot by walking diagonally . Count the number of adults trapped and work out the average per sweep and grade. (< 5 Mild; 5-10 Moderate > 10 severe).

ETL

  • 5 insects per sweep.
  • For cucurbits which are trailed on pandal : Select 5 pits at random from the plot. Assess the total number of feeding holes of the adult 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 holes per leaf. Less than 5 -Mild, 5-10 Moderate >10 severe.
  • 5 holes per leaf.

    • Control Measures

  • Collect and destroy adult beetles using hand nets in cucurbits which trail on ground.
  • Burn the pits prior to raising the crop.
  • Apply neem cake @ 100 g per pit 10 days before sowing.
  • Spray quinalphos 25 EC @ 2 ml per liter of water and also drench the pits.