University of Illinois Extension

University of Illinois Extension

Hort Answers

Insect Damage

Stink Bug
Several genera and species

Brown stink bug adult on broccoli. P. Nixon.
Brown stink bug adult on broccoli. P. Nixon.
4 (1 = rare 5 = annual)
2 (1 = very little damage 5 = plants killed)
Need info...


Stink bug adults are green or brown, flat-topped insects that are about 1/2 inch long. They are shield-shaped, with a large triangle on their backs. They lay their eggs in clusters on the leaves. Nymphs are rounded, variously colored, and look little like the adults until they approach maturity.

Stink bugs are a contaminant in harvested peas because the nymphs are the correct size and shape to be indistinguishable from the peas by mechanical harvesting equipment.

Life Cycle

Most overwinter as adults and lay clusters of barrel-shaped eggs on flowering plants and fruits in the spring and early summer. Nymphs (immature stages) feed on similar host plants. At the site where they insert their feeding stylets (beaks) into plants, cells are killed and subsequent growth around those cells may take on a distorted shape. Different species may undergo 1, 2, or 3 generations per season before adults become dormant to pass the winter.

Use a sweep net to scout pea fields within a few days of harvest to determine if a problem with stink bugs exists. If necessary, use an insecticide with a short preharvest interval to control the stink bugs. An alternative to an insecticide application is to adjust blowers and air cleaners within the processing plant to effectively remove the bugs.

Related Resources
Home, Yard & Garden Pest Guide
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic