Because of delayed planting and a cool summer,

Kentucky soybean producers are likely to have considerable acreage of late-maturing soybeans. This probably causes most folks to be concerned with frost. However, this extended maturity may also set up fields for additional damage by stink bugs. Producers and consultants should remain watchful as long as pods are still filling.

By far, the most common stink bug found in Kentucky is the green stink bug. Our research indicates that green stink bugs make up greater than 80 percent of the population. Nonetheless, there are several species of brown stinkbugs in Kentucky-grown beans as well.

Stink bugs can cause decreases in both yield and seed quality. These pesky bugs feed directly on the bean using their piercing-sucking mouth parts. They puncture the pod wall and stab the developing bean, removing nutrients and sometimes allowing entrance of pathogens into the pod / bean. Usually, there is no clear evidence of this damage until the pods are mature. The only clear evidence one has of these important pests is observing them in the field; damage symptoms are too late.

Stink bugs will hang around until frost, feeding on whatever is available to them. In soybeans we consider the pods at risk up through to R6 stage. So if you have beans less mature than this you should definitely be looking for these critters. Once soybeans are in the R6 stage stink bug damage is much more difficult to predict.