Other vegetable crops likely to be injured include bean, beet, celery, potato, pepper, and tomato. Damage - On most crops, borers begin feeding on the leaf surface. In corn, feeding first occurs in the whorl. Later the larvae bore down midribs of leaves into the stalk. Frass and silk near entrance holes are evidence of their presence.
Borers weaken stalks, or stems, and interfere with the movement of plant nutrients.
Consequently, yields are reduced. On infested corn plants, tassels and stalks may break, ears drop, or only small ears develop. Potatoes and peppers are affected more adversely than corn by borer injuries which allow the entrance of bacterial and fungal pathogens. Reduced yields occur when disease organisms cause stems to collapse and tubers to rot. Potatoes that are produced on infested plants are often of poor quality due to the development of diseases such as black leg.