Say’s Stink Bug: Appearance, Territory, Damage and Life Cycle

Latin Name: Chlorochroa Sayi

Appearance: Say’s stinkbug is one of numerous green species found in the United States. They are rather huge, reaching about 34 inches in length, and have the traditional shield-shape when viewed from above. They are green in the spring and summer, becoming brownish in the fall, with faint golden borders around their thorax and wings, which are retained flattened and molded to the top of the abdomen when resting. The huge triangular scutellum between the bases of the wings is typical of stinkbugs.

Hosts Plants: Early in the growing season, say stink bugs graze on weeds, mainly Russian thistle, and other wild hosts before dispersing into cereal grain fields during heading and grain fill. Alfalfa and sugar beet are two more crops that have been impacted.

Territory: Native to western North America.

Damage Insect Cause: Early in the growing season, say stink bugs graze on weeds, mainly Russian thistle, and other wild hosts before dispersing into cereal grain fields during heading and grain fill. Alfalfa and sugar beet are two more crops that have been impacted. Adults and nymphs both have piercing-sucking mouthparts that they put into plant tissue to extract fluids. Cereal plants are appealing even in the boot stage, and the bugs will continue to eat on growing grains until the mouthparts can no longer be inserted. Feeding during the boot stage might result in heads that are sterile and sun-bleached. Early feeding can lower grain number as well as weight, but later feeding just affects grain weight. Say stink insect eating results in shriveled, malformed, and light grains.

Life History and Habits: Smelly bugs are big insects with a triangular thorax. Adults are green in the summer and become brown or gray in the autumn. Females deposit tiny, cylindrical eggs in clusters on plant surfaces, which hatch into nymphs. Nymphs resemble tiny, undeveloped adults who lack wing coverings. As they grow into adults, they undergo a progressive transition (metamorphosis) over three to four weeks. Adult stink bugs overwinter beneath plant detritus. Depending on the duration of the growing season, there are one to three generations every year.