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How to Manage Pests
UC Pest Management Guidelines
Small Grains
Bird Cherry-oat Aphid
Scientific name: Rhopalosiphum padi
(Reviewed 2/07,
updated 2/09)
In this Guideline:
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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.
Biological Control
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.
Cultural Control
Bird
cherry-oat aphid can build up on volunteer cereals; destroy these plants before
newly planted crops emerge to help reduce aphid numbers.
Management Decisions
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.
| Common name |
Amount/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
|
| The following materials are listed
in order of usefulness in an IPM program, taking into account efficacy, information
relating to natural enemies and honey
bees as
well as the environmental impact. |
| |
| A. |
METHYL PARATHION* |
| |
(Penncap M) |
1–2 pt |
5 days |
15 |
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MODE OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS: May be used on wheat, barley, and
oats. Do not graze within 15 days. This material is toxic to bees exposed to direct application. Apply late evening, night, or early morning. |
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| B. |
DIMETHOATE 4EC |
0.5–0.75 pt |
48 |
60 |
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MODE OF ACTION GROUP NUMBER1: 1B |
| |
COMMENTS: For use on wheat and triticale
only. Do not make more than 2 applications/year. Do not graze within 14 days.
Do not graze within 14 days. Highly toxic to honey bees if bees are present at treatment time or within a day after. |
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| C. |
MALATHION 8EC |
1.25 pt |
12 |
7 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: May be used on wheat, barley,
oats, rye. If alfalfa is in bloom, apply during the night or early in the morning when bees are not foraging in the field. |
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| D. |
METHOMYL* |
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(Lannate SP) |
0.25–0.5 lb |
48 |
7 |
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MODE OF ACTION GROUP NUMBER1: 1A |
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COMMENTS: May be used on barley, oats,
rye, and wheat. Do not graze within 10 days. Do not apply more than 1.8 lb
a.i./acre/crop. Highly toxic to honey bees if bees are present at treatment time or within a day after. |
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| E. |
CHLORPYRIFOS* |
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(Lorsban) 4E |
0.5–1 pt |
24 |
28 |
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MODE OF ACTION GROUP NUMBER1: 1B |
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COMMENTS: For use on wheat only. Do not
make more than 2 applications/crop. See label for other restrictions. Highly
toxic to honey bees if bees are present at treatment time or within a day after. Avoid drift and tailwater runoff into surface waters. |
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UC IPM Pest Management Guidelines: Small Grains
UC ANR Publication 3466
Insects and Mites
C. G. Summers, Entomology, UC Davis/Kearney Agricultural Center, Parlier
L. D. Godfrey, Entomology, UC Davis
Acknowledgment for contributions to Insects and Mites:
D. Gonzalez, Entomology, UC Riverside
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