Bean leaf beetle grub
- Adult: Vary in color and markings, but are usually a reddish-brown or yellow with black edges and, often, three black spots on each wing. All bean leaf beetles have a black triangular marking on the front edge of each wing.
- Larvae: White with a brown mark on each end.
- Eggs: Orange, lemon-shaped and 1 mm long.
Timing of damage: All season
Type of damage: Leaf defoliation and pod feeding.
Scouting: Examine five plants in five locations and determine the percentage of defoliation, or inspect the pods of plants in 2' of a row in five different locations to determine the percentage of pod damage.
Economic threshold: In V stages: more than 40% defoliation. In stages R1 to R5: more than 15%
defoliation. In stage R6: more than 25% defoliation with active beetles. For pod feeding: when 10% of pods are damaged and 10 or more beetles are seen per foot of row.