The corn, not the worm! The corn is perfectly fine 99% of the time.
What Is a Corn Worm?
The corn earworm, Helioverpa zea, is the larva, or caterpillar, of a moth. There is almost always only one per ear because they are cannibalistic and the remaining worm will have eaten the others. They tend to inhabit the tip of the ear, feeding on the kernels. I have seen a lot of people at the local farmers' market rejecting ears of otherwise excellent corn because there's a worm. What a waste! Organic corn often has a worm, because spraying with toxic insecticides is the only way to prevent them. This is a purely cosmetic issue, the rest of the ear is safe to eat. All you need to do is cut off the tip of the ear, removing the worm and the damaged kernels, and you'll be fine. I'd much rather eat an ear of corn that had a worm removed than one soaked with insecticides.
These creatures are also pests of many other crops including tomatoes, cucumber, eggplant, lettuce, lima bean, melon, okra, pea, pepper ... you get the idea!
When it is mature, the caterpillar (left) drops to the ground where it burrows into the soil where they pupate for a couple of weeks before hatching into the adult moth. In some rural areas of Mexico these worms are collected for food and are considered a delicacy.
