Corn Worms and Pheromone Traps

The farming neighbor next to us grows sweet corn, called Olathe Sweet-Sweet Corn, for America’s adoring population of sweet corn eaters. It is a patented “delicious sweet corn watered with melted snow” so the advertising states.

To keep the sweet corn free of corn ear worms (people don’t like to see worms in their corn) pheromone traps are hung throughout the fields to capture the egg-laying earworm moths and prevent them from producing.

Corn ear worms are 1- to 2-inch caterpillars that are green, yellow, pink or brown with a white stripe and black legs. They pupate into tan-colored moths with a 1 1/2- to 2-inch wingspan.

As the larvae mature, they continue to feed on the corncob and work their way down the ear. As the corn itself matures, a second-generation infestation of corn earworm occurs as the larvae travel down the silk vein into the maturing cob where more significant crop damage occurs. The corn earworms even eat one another, normally leaving one corn earworm per cob until it eats its way out by eating a hole through the husk.

As a side note earworm pupae, which live in the ground can cause re-infestation in the spring.  Sweet corn fields are plowed as soon as harvest is over.

Anyway, we are now seeing the pheromone traps hanging on fence-lines identifying sweet corn fields across our mesa.