Disease & Insect Pictures

This page showcases disease and insect images on oat and wheat plants to aid in pest identification. Click on an image to view the full-size version in a new tab.

Diseases

Damage by Xanthomonas on wheat plant. Details in text following the image.

Black chaff (black discoloration) on wheat panicle and bacterial leaf streak (chlorosis surrounding necrosis) on wheat leaves [Xanthomonas translucens spp.]

Black point on wheat seeds. Details in text following the image.

Black point discoloration [Alternaria spp., Bipolaris spp., and others] on wheat kernels

Crown rust damage on oat leaves. Details in text following the image.

Crown rust [Puccinia coronata] pustules on oat leaves (bright orange color can help distinguish crown rust from the darker, more brick-red color of stem rust)

Two oat plots with contrasting amounts of crown rust damage. Details in text following the image.

Extensive leaf area coverage by crown rust [Puccinia coronata] pustules on a susceptible oat line (left) versus a more resistant line (right)

Fusarium damage on wheat heads. Details in text following the image.

Fusarium head blight, or scab [Fusarium spp.], causing premature bleaching on wheat heads

Fusarium damage on a wheat head. Details in text following the image.

Fusarium head blight, or scab [Fusarium spp.], causing premature bleaching on the middle of a wheat head

Wheat kernels discolored by Fusarium damage. Details in text following the image.

Fusarium head blight, or scab [Fusarium spp.], damage on wheat kernels. Notice the pinkish-orange discoloration

Oblong halo blight lesions on oat leaves. Details in text following the image.

Large halo blight [Pseudomonas syringae pv. coronafaciens] lesions on oat leaves with concentric halo of chlorosis surrounding oblong necrotic regions

Soil-borne Wheat Mosaic Virus damage on wheat leaves. Details in text following the image.

Patterned chlorosis ('mottling') of soil-borne wheat mosaic virus on wheat leaves

Coalescing of extensive chlorosis ('mottling') on wheat leaves caused by soil-borne wheat mosaic virus

Stem rust damage on oat stem. Details in text following the image.

Stem rust [Puccinia graminis f. avenae] pustules on oat stem (note the dark orange color and ripped stem tissue surrounding where the pustules erupted)

Stripe rust damage on wheat plants. Details in text following the image.

Stripe rust/yellow rust [Puccinia striiformis] pustules on wheat leaves (note the light orange color and formation of 'stripes' by clustered pustules)

Photo of tan spot damage on oat leaves. Details in text following the image.

Tan spot's small, scattered, purplish, early lesions [Pyrenophora tritici-repentis] on oat leaves

Tan spot damage on an oat spikelet. Details in text following the image.

Purplish spots of tan spot [Pyrenophora tritici-repentis] on oat spikelet

Advanced tan spot damage on an oat stem. Details in text following the image.

Small, black fruiting structures (pseudothecia) of tan spot [Pyrenophora tritici-repentis] erupting from cuticule on oat stem

Insects

Hessian fly pupae in wheat roots. Details in text following the image.

Brown, spindle-shaped pupae of Hessian fly [Mayetiola destructor] in wheat roots

Hessian fly pupae in wheat crown. Details in text following the image.

Hessian fly [Mayetiola destructor] pupae (dark brown, spindle-shaped, lighter reddish-brown at one end) in wheat crown

Hessian fly pupae and larvae in wheat crown. Details in text following the image.

Hessian fly [Mayetiola destructor] pupae (light brown spindle-shapes) and larvae (white maggots) in wheat crown