Bird-cherry oat aphid
- Adult: Olive green or dark green in color, round, soft-bodied and have a rust-colored spot on the posterior end. Appear in clusters in the leaves and upper cornstalk and secrete a sticky sugary substance called honeydew.
- Nymphs: Resemble the adults, but smaller.
- Eggs: Females do not lay eggs but give birth to live young.
Timing of damage: V6 to R1
Type of damage: Wilted, curled and yellowed leaves. Tassels and silks may be covered with honeydew, which can affect pollination.
Scouting: Examine the whorls of 20 plants in five locations (for a total of 100 plants). Note the number of aphids per plant.
Economic threshold: Treat if 50% of plants have more than 100 aphids per plant and the plants are under stress.