Wireworms can damage corn, resulting in stand loss during the seedling stage. Wireworms are the immature stage of click beetles and they range in length from 1/4 to 1 1/2 inches. Wireworms are found most often in grasslands or fields recently planted in sod. Occasionally, they are found in fields without any recent history of grasses. Why wireworms occur in damaging numbers in fields without grasses is a mystery.