Information gathered by Scott Storey

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Information gathered by Scott Storey Drawings by
Justin Spurlin
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Rhopalosiphum padi
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Physical Characteristics Can reduce forage and
grain yields.Does not cause visible symptoms in
the wheat but heavy infestations will cause
plants to become sticky with honeydewVery
efficient vector of the virus that causes Barley
Yellow Dwarf disease DamageOlive-green color,
has a red orange patch surrounding the base of
each cornicleOld aphids found in winter or
early spring Could be totally black in color,
but will give birth to more typical aphids in the
springMeasures about 1/8 inch long
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Schizaphis graminum
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Physical CharacteristicsLime-green colored
Darker green stripe on its backOuter half of
its antennae, outer half of its legs and the tips
of its cornicles are blackMature greenbug
measures about 1/16 inches long Damage Causes
yellowing of young wheat leavesOrange-red spots
on the leaves of older plantsOften occur in
concentrated patches in the fieldDamage
frequently occurs as small circular patches Can
carry the virus causing Barley Yellow dwarf
disease
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Diuraphis noxia
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Physical CharacteristicsLime green in color,
spindle shapeShort antennae, no prominent
cornicles, a projection above tail giving a
double tail appearance Mature RWA is about
1/16 of an inch long DamageSerious injury, yield
loss even at low levels because it injects
chemicals that affect plant growthAs it feeds,
causes leaf to curl, creating an enclosure
protecting it from climate, natural enemies, and
insecticides. Symptoms become visible as white,
yellow, or purple streaks
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Sitobion avenae
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Physical Characteristics Larger than greenbug,
has a spidery appearance due to its long legs
and long narrow cornicles Body is lime green,
but legs and cornicles are black The English
grain aphid is 1/8 inch long when
mature. DamageMore common in the late growing
seasonPrefers to feed on awns and wheat
headsSeldom reduces yields, generally does not
require controlIs vector virus that causes
Barley Yellow Dwarf disease
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Rhopalosiphum maidis
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Physical CharacteristicsBluish-green with short
black cornicles and black antennae and legsThe
corn leaf aphid is not considered an economically
important pest of wheat in Oklahoma. More
commonly found in corn and sorghum, but may be
found on seedling wheat in the autumn or on
mature wheat late in the growing
season.DamageIt is a known vector of the virus
that causes Barley Yellow Dwarf disease
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Identifying insect pests can help determine
problems before they proliferate. Knowing the
difference between pest insects and natural
enemies can also help. To view the presentation
on natural enemies, click here.