- 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.
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).