How to Manage Pests
UC Pest Management Guidelines
Bird Cherry-oat Aphid
Scientific name: Rhopalosiphum padi
(Reviewed 2/07, updated 2/09, pesticides updated 7/16, corrected 7/19)
In this Guideline:
Bird cherry-oat aphid is the most common aphid found on cereals. Its color ranges from orange green to olive green to dark olive green, and sometimes greenish black. It has long antennae and long tube-shaped cornicles arising from the side of the abdomen near the rear end. Wingless forms frequently have a reddish orange patch around the base of the cornicles. Bird cherry-oat aphid may be found any time after seedling emergence but is most common in February and March. The bird cherry-oat aphid is most easily confused with the corn leaf aphid but the former has a rounded, bulblike body shape while the latter appears almost rectangular.
Bird cherry-oat aphid attacks all small grains including wheat, barley, oats, rye, and triticale. It may also be found on sorghum and corn. Heavy populations may cause a golden yellow streaking on the leaves; do not confuse this with the white streaks caused by Russian wheat aphid. Occasionally heavy populations cause the flag to curl up in a tight corkscrew fashion that may trap the awns, resulting in a fish-hook appearance to the head. Leaf curl caused by the bird cherry-oat aphid resembles a corkscrew, while that by the Russian wheat aphid resembles an upright soda straw.
Bird cherry-oat aphid is a vector of BARLEY YELLOW DWARF virus.
Bird cherry-oat aphid populations are usually kept under control by a combination of predators and parasites (see APHIDS – GENERAL CONSIDERATIONS). Before considering chemical controls, evaluate the activity and control potential of these natural enemies.
Bird cherry-oat aphid can build up on volunteer cereals; destroy these plants before newly planted crops emerge to help reduce aphid numbers.
Economic thresholds for bird cherry-oat aphid are not well established. Do not consider treatment until the number of aphids exceeds 50-60 per tiller. Chemical controls should then be applied only if there is no evidence of natural enemy activity or if the plants are several weeks from flowering.
UC IPM Pest Management Guidelines:
Insects and Mites
L. D. Godfrey, Entomology, UC Davis
Acknowledgment for contributions to Insects and Mites:D. Gonzalez, Entomology, UC Riverside
C. G. Summers, Entomology, UC Davis/Kearney Agricultural Center, Parlier