Source: Iowa State University
Stink bugs are often more prevalent in soybean fields around this time of year, especially in the southern half of Iowa. Stink bug nymphs and adults are fluid feeders with piercing-sucking mouthparts. Most species are herbivores but a few are beneficial predators. Because herbivorous stink bugs build up in soybean after bloom, they can be found feeding on developing pods, resulting in shriveled, desiccated seeds. The species below are known to occasionally cause problems for Iowa producers.
The Green stink bug (Acrosternum hilare) migrates up from southern states each summer and has only one generation per year in Iowa. They usually begin feeding in soybean in early August. Green stink bug nymphs are black with bright green and yellow or red markings. Adults are light green, shield shaped, and have fully developed wings. They are large, about 5/8 inch long.