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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 2/07)
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.
DAMAGE
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 cork-screw 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.
MANAGEMENT
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 impact
on natural enemies and honey bees.
When choosing a pesticide, also consider information relating to
environmental impact.
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| A. |
METHYL PARATHION* |
| |
(Penncap M) |
1–2 pt |
5 days |
15 |
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MODE OF ACTION: An organophosphate (Group
1B)1 insecticide.
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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: An organophosphate (Group
1B)1 insecticide.
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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: An organophosphate (Group
1B)1 insecticide.
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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* |
| |
(Lannate SP) |
0.25–0.5 lb |
48 |
7 |
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MODE OF ACTION: A carbamate (Group 1A)1
insecticide.
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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: An organophosphate (Group
1B)1 insecticide.
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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 the insect and mite section:
D. Gonzalez, Entomology, UC Riverside
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