Spiders & Bugs That Live in Corn Fields

The waving stalks of a corn field are home to more than just a delicious vegetable. In most fields that are not treated with pesticides, a vast array of insects can be found. While this can make for a productive science field trip, the presence of these highly destructive bugs can be a financial drain for farmers mass producing corn or a frustration for a backyard gardener trying to produce their own crop.

  1. Spider Mites

    • These insects have eight legs as adults and six as larvae. They are nearly microscopic so the most obvious evidence of their presence is the silver-colored webs they leave behind. They gather and feed on the underside of leaves. Their feeding leaves the plant with an appearance similar to that of drought. There are two dominate species: the carmine spider, mite with red oval-shaped females and smaller diamond-shaped males; and the two-spotted spider mite, with yellowish dark green females and diamond-shaped males.

    Beetles

    • There are five predominant and destructive species of beetles that chew on the foliage and silk of corn. The billbug is a black, gray or brown beetle with a snout that pierces seedlings, causing stunting and, in some cases, plant death.

      The sugarcane beetle is black with as hard dome-shaped shell. It feeds on the lower stalks of corn seedlings.

      The corn flea beetle chews on foliage of corn stalks leaving behind small round holes.

      The Japanese beetle feeds on the corn silks and causes massive reductions in pollination.

      The spotted cucumber beetle does its best damage by severing newly emerging yet unpollinated corn silks, leading to a drastic reduction in the infilling of corn ears.

    Grasshoppers

    • Grasshoppers begin their feeding on the outer edges of the leaves. They work their way in toward the stalk and will consume that next if not controlled. They will continue to chew on silks and developing corn ears until they have completely destroyed the plant.

    Caterpillars

    • In their larvae state, caterpillars reside in large numbers in corn fields when not controlled by pesticides. They can cause unrecoverable damage to a crop. The corn earworm bores deep into the seed head and consumes its contents and flower stems. The sorghum webworm feeds on the corn's grain. It spins impenetrable webs between flowers and seeds thus effectively reducing pollination efforts by other insects.

    Corn Root Aphid

    • This wingless pale green to blue green aphid has a black head and reddish eyes. It prefers to live near anthills in corn fields. It feeds on the roots of corn, and its presence is evidenced by foliage that is developing a yellow and or red tint.

    Chinch Bug

    • This insect, with its average size of .16 inches in length, is one of the easiest corn field violators to spot with the naked eye. It has opaque wings, each marked with a black triangle. It feeds on roots and upper leaves, causing yield reductions in established corn stalks and wilt in seedlings.