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Plantwise Factsheets for Farmers
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Corn Earworm Control

Recognize the problem

The corn earworm is also known as "ut'us khuru" or "shiuri". Harvested corn ears are sold at a good price, provided that they are not damaged by the corn earworm. Attack by this worm is observed in the first grains of the ear.


The corn earworm eats the milky grains of corn three months after sowing.

Adult females lay their eggs on the ear silk. There, the eggs hatch and enter the ear.

The corn earworm breathes through skin pores. Vegetable oil closes the pores, making the worm suffocate and die.


You can control the corn earworm with edible vegetable oil.

Apply 2-3 drops of vegetable oil to each ear when they are in milk stage, or in doll stage.

Use a piece of sponge or a dropper to exactly count the oil drops. Squeeze 2 or 3 drops of oil onto the silk of each ear, making sure that the oil enters the ear.

Check the ears the next day to ensure that the worm has died.

It is recommended that this type of control be done before the hot season as a preventive measure to avoid more corn earworms in the crop.
Scientific name(s) > Helicoverpa zea

The recommendations in this factsheet are relevant to: Peru

Authors: Luis Torres Medina
National Institute of Agricultural Innovation
tel: (51) 349-2600 Anexo - 276; 952063396 email:
Edited by
Created in Peru October 2012