Bird-cherry oat aphid
- Adult: Olive green or dark green, round, soft-bodied and with a rust-colored spot on the posterior end. Appear in clusters in the leaves and upper cornstalk. Prefer cereal grains but will also feed on corn. Secrete a sticky sugary substance called honeydew.
- Nymphs: Similar to the adults but smaller.
- Eggs: Females give birth to live young.
Timing of damage: Fall and spring
Type of damage: Aphids feed on plant sap. Plants may have rolled leaves and fishhooked heads and be covered with honeydew.
Scouting: Examine plants for aphids in various field locations to determine a field-wide average.
Economic threshold: An average of 20 or more aphids per tiller and fewer than 10% of tillers with parasitized aphids or lady beetles.