General Pests: Seedling to Stand Establishment / Dry Beans / Agriculture: Pest Management Guidelines / UC Statewide IPM Program (UC IPM)

Use the photos below to identify damage to seedlings. Names link to more on identification and management.

Click on photos to enlarge
Blank spots in rows—seedlings completely removed, failed to emerge or slow emergence; poor stand establishment
Seedcorn maggot damage Identification tip: Seedling severely damaged before it emerges by seedcorn maggot chewing.	Symphylans Identification tip: Slender, white arthropods, closely related to insects, about 1/3 inch, with 10 to 12 appendages and distinct antennae; may damage seedlings before or after emergence and may slow growth of larger plants.	Wireworms Identification tip: A wireworm was found feeding inside the stunted dry bean seedling on the right.
Pythium spp. preemergence rot Identification tip: Bean seeds rotting from Pythium rot infection.	Gophers Identification tip: Crescent-shaped mound and plugged burrow opening of a pocket gopher, Thomomys sp.
Seedling collapse soon after emergence
Rhizoctonia solani infected seedlings Identification tip: Infected bean seedlings (center) collapse.	Rhizoctonia solani infected seedling Identification tip: Sharp-edged oval to elliptical reddish brown lesions on base of developing stem.	Thielaviopsis basicola infected seedling Identification tip: Blackeye bean seedling collapse.
Pythium spp. infected seedling Identification tip: Water soaked lesions on base of developing stem.	Charcoal Rot infected young plant Identification tip: Infected roots brown to black.	Wireworms Identification tip: Shiny, slender, cylindrical, yellow-to-brown, wirelike larvae (of click beetles) found in soil.
Symphylans Identification tip: Slender, white arthropods, closely related to insects, about 1/3 inch, with 10 to 12 appendages and distinct antennae; may damage seedlings before or after emergence and may slow growth of larger plants.	Seedcorn maggot damage Identification tip: Seedlings with feeding damage to root and seed, with maggot on seed (right).
Leaf damage
Cucumber beetle adult and damage Identification tip: Adults chew holes in leaves, skeletonizing them.	Cowpea aphid damage Identification tip: Feeding causes bean leaf curling. (Cowpea aphids in photo are rare color variant, they are usually shiny black.)	Leafminer larva and damage Identification tip: Yellow larva (center) was removed from the inside of the leaf where it was feeding; it is blunt at rear, and pointed in front; feeding causes threadlike twisting lines in leaf.
Thrips damage Identification tip: Plants look ragged; distorted leaves turn brownish around edges and cup upward.
Stunted seedlings
Aphid damage Identification tip: Feeding stunts plants.	Baldhead Identification tip: Seedlings have little or no growth above the primary (first) leaves as a result of death or damage of the growing point
Seedling leaves, roots, or stem eaten off; seedling cut off, at, or below soil line
Darkling beetles Identification tip: spotty infestations; young plants girdled or cut off at or below the soil surface.	Rabbits Identification tip: Leaves and stem parts chewed off; rabbit droppings next to damaged plant.	Cutworm damage Identification tip: Seedlings (right) clipped off just above soil line.
Gopher mound Identification tip: Characteristic crescent-shaped mound and plugged burrow opening.	Wireworms Identification tip: Shiny, slender, cylindrical, yellow-to-brown, wirelike larvae (of click beetles) found in soil.	Seedcorn maggot damage Identification tip: Seedlings with feeding damage to root and seed, with maggot on seed (right).
Atypical color
Sunscald Identification tip: Dry brown patches on leaves.	Herbicide damage Identification tip: Kidney bean seedling (left) with chlorotic and cupped leaves caused by oxyfluorfen herbicide.

Text Updated: 06/16