General Pests: Bud Through Bloom / Dry Beans / Agriculture: Pest Management Guidelines / UC Statewide IPM Program (UC IPM)

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.	Nematode damage Identification tip: Wilted and stunted plant has root galls (right) compared to healthy plant (left).
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).
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.
Leaves with holes; skeletonized leaves
Armyworm young larva and damage Identification tip: Newly hatched larva scrapes leaf tissue, "skeletonizing" leaf.	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.
Leaves with mines
Leafminer damage Identification tip: Wavy tan leaf mines in surface of bean leaves.
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.
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.	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.
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.
Leaves with stippling
Spider mite damage Identification tip: Very fine white or yellow stippling; fine webbing on leaf undersurface.	Leafhopper damage Identification tip: White stippling on upper surface of leaves; small white cast skins, tiny dark varnishlike spots on undersurface of lower leaves.

Text Updated: 06/16