European corn borer larvae feed on young leaves and flowers causing them to be distorted and brown. They bore in the stem causing death of plant parts above the bored area. No chemical control is listed. Stalk borer also bores in the stems. No chemical control is listed.
Leafhoppers cause leaf discoloration along the leaf margins which spreads toward the mid-vein.
The affected area is at first yellowish but becomes brown and brittle. If not controlled, the plants are stunted. Leafhoppers are controlled with Diazinon dust or sprays of Orthene, rotenone, methoxychlor, or Sevin. Thrips cause the under surfaces of petals to turn white and wither. Thrips are controlled with Sevin or rotenone.