European corn borer in ear shank can cause dropped ears. Stalk rot can complicate the picture. Tunneling by corn borers provides stalk rots with a convenient entry point. More stalk rots usually accompany a corn borer infestation. Stalk rots attack the pith of lower internodes, contribute to premature plant death, weaken the stalks and thereby cause additional lodging.
Farmers typically delay harvest to reduce grain moisture and save on drying costs.
But a corn borer infestation increases the risk of harvest losses. As ear shanks dry, they become more brittle and more likely to drop when buffeted by strong winds. Likewise, lodging from stalk rots or breakage in tunneled stalks will increase. The dilemma for most farmers is a simple one. Regrettably, there's no easy answer, but we can make an educated guess.