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Dry
Beans > Year-Round IPM Program > Flower
Bud through Bloom > Damage
to Plants
Dry Beans
Pests and their Damage to Plants—Bud through Bloom
On this page
- Charcoal rot
- Pythium spp.
- Fusarium root rot
- Fusarium wilt
- Nematodes
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- Alfalfa mosaic virus
- Bean yellow mosaic virus
- Bean common mosaic virus
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- Armyworms
- Loopers
- Saltmarsh caterpillar
- Cucumber beetles
- Leafminers
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- Aphids
- Common bacterial blight
- Spider mites
- Leafhoppers
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Use the photos below to identify damage.
Names link to more on identification and management.
Click on photos to enlarge
| Collapsed,
wilting, stunted, or dying plants |
Charcoal rot damage
Identification
tip: Charcoal-like dust on stem surface.
|
Pythium spp. (blackeyes)
damage
Identification tip: Blackeye bean stem tissue dries
out, becomes sunken, and turns tan to brown in color when
infected. |
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Fusarium root rot damage
Identification tip: Brick-red lesions of variable
size on belowground stems, tap roots; red lesions turn
brown; small red flecks under scraped lesion surface.
|
Fusarium wilt (of blackeyes)
damage
Identification tip: Pale green, flaccid leaves
turn yellow and drop off; brown
discoloration in center of root, stem, and some branches
(seen when sliced). |
Nematode damage
Identification tip: Wilted and stunted plant has
root galls (right) compared to healthy plant (left).
|
| Yellowing,
mottled, distorted leaves |
Alfalfa mosaic virus
Identification tip: Yellow leaf mottling.
|
Bean yellow mosaic virus damage
Identification tip: Infected leaves bright yellow
to green mosaic, or mottled; leaves distorted, cupped downward,
and wrinkled; differs from bean common mosaic virus symptoms,
which cause light and dark green mosaic leaf patterns. |
Bean common mosaic virus
Identification tip: Green-yellow and dark green
mosaic pattern on leaves; discoloration usually accompanied
by puckering, blistering, distortion, downward curling.
|
cucumber mosaic virus
Identification tip: Symptoms vary considerably from a light-green to dark-green mottle, blisters and vein banding, interveinal yellowing and leaf distortion.
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| Leaves
with holes; skeletonized leaves |
Armyworm young larva and
damage
Identification tip: Newly hatched larva scrapes leaf tissue, "skeletonizing" leaf.
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Armyworm older larva and
damage
Identification tip: Older larva chews large sections
of leaves. |
Loopers damage
Identification tip: Chew holes in mature leaves.
|
Cucumber beetle adult
and damage
Identification tip: Chews holes in leaves.
|
Saltmarsh caterpillar young
larvae and damage
Identification tip: Young larvae feed in groups, chewing
holes in leaves. Older larvae (not pictured here) feed individually. |
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| Leaves
with mines |
Leafminer damage
Identification
tip: Wavy tan leaf mines in surface of bean leaves.
|
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Curled
leaves |
Aphid damage
Identification
tip: Curled, sticky, and shiny leaves, sometimes with
black sooty mold.
|
Cowpea aphid adults
Identification tip: Shiny black. Legs and antennae
white to pale-yellow with black tips. |
Bean aphid adults
Identification tip: Slightly larger than the cowpea
aphid; dark olive green to black with light-colored legs.
|
Curly top
Identification tip: Puckered, wrinkled, dark green leaves with edges curled downward. The internodes become shortened, resulting in stunted plants.
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| Leaves
with spots |
Common bacterial blight damage
Identification
tip: Irregularly shaped spots bordered by a lemon-yellow ring;
as spots enlarge, tissue in center dies and turns brown.
|
Alfalfa mosaic virus
Identification tip: Yellow leaf mottling. |
Bacterial brown spot
Identification tip: Oval spots with dead tissue in the center surrounded by a narrow zone of light-green tissue. The centers of the spots may fall out resulting in tattered appearance.
| 
Halo blight
Identification tip: Small, angular, water-soaked spots on the undersurfaces of leaves turn brown and develop characteristic light green to yellow halo around.
|
| Leaves
with stippling |
Spider mite damage
Identification
tip: Very fine white or yellow stippling; fine webbing
on leaf undersurface.
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Leafhopper damage
Identification tip: White stippling on upper surface
of leaves; small white cast skins, tiny dark varnishlike
spots on undersurface of lower leaves. |
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