By Blake Jackson
Missouri soybean, corn, and cotton crops have been dealing with stink bug infestations since the 1990s. According to University of Missouri Extension state field crops and forage entomologist Ivair Valmorbida, stink bugs feed on a wide range of plants, including corn and soybeans.
In Missouri soybeans, green stink bugs account for more than 70% of the population. Both adults and nymphs use their piercing-sucking mouthparts to extract fluids from developing pods and seeds. True to their name, stink bugs release a strong, unpleasant odor when disturbed.
While the brown marmorated stink bug is also present, it is far less common than the green stink bug. These insects overwinter as adults and become active in the spring as temperatures rise and day length increases.
Stink bug feeding can significantly reduce soybean yields and compromise seed quality. Affected seeds often shrivel, shrink, and become discolored or deformed. The damage usually goes unnoticed until harvest, making timely intervention challenging.
Valmorbida’s team surveyed 316 Missouri soybean fields in 2024 and 2025, finding green stink bugs the most prevalent, followed by the brown stink bug complex. Adults are generally light green with shield-shaped bodies, while barrel-shaped eggs shift from light green to yellow and are typically found on the undersides of leaves.
Stink bugs are most likely to infest soybeans from mid-July through harvest. Scouting fields regularly is crucial for management. Valmorbida recommends weekly scouting once plants begin to bloom, checking both interior and edge rows, particularly near weedy or wooded areas, where infestations are most common.
Photo Credit: istock-bee-photobee
Categories: Missouri, Crops, Corn, Soybeans