Cerotoma trifurcata
Coleoptera: Chrysomelidae
Identification
Adult beetle is 1/4" long, yellowish or reddish, with or without
four black spots and two marginal stripes on the back. (a)
Adults always have a black triangular spot at the base of the wing
covers, behind the neck.
Damage
Adults eat holes in the leaves (b) and pods of beans (c).
Adults feed heavily on seedlings and may kill or severely stunt them.
Larvae feed on the roots and can cause damage.
Management
Plant garden beans after soybeans are planted in the area. Overwintering
beetles will have many more soybeans to feed on and be less numerous in
the garden.
Beans can tolerate many holes in the foliage without having a reduction
in pod production.
Insecticides are effective.