Late season kernel injury associated with scarring or bruising of kernels that may result in a “mottled” appearance, especially near the tip of the ear. When stink bug feeding is severe during early grain fill it may deform into cow horn, boomerang, or banana shapes – see “Cow Horn”, “Boomerang”, or “Banana” Ears.
Kernel damage is associated with brown marmorated stink bugs (BMSB), brown, and green stink bugs.
In Ohio feeding has been limited to late season feeding and scarring without major yield or quality losses. In the southern states, stink bugs cause significant losses in field corn. Sweet corn is also particularly susceptible to stink bugs, with similar damage symptoms. When stink bugs pierce through the husk and feed on the ear during early development, the cob will not develop on that side, but continue growing on the back side giving the ear a characteristic banana shaped appearance. The shuck will also stop developing, exposing the grain to bird and insect damage. Injury also includes shrunken and/or missing kernels. Heavy stinkbug populations can reduce not only yields but also the quality of the grain. While we have not seen any economic losses from stinkbugs in field corn, growers should be aware of their presence and the damage they can cause.