Byron Hendrix, Agronomist with Terayne AG Specialties, Venedy, IL, observed green and brown stink bugs in soybean fields in Washington County on June 25. The field in which stink bugs were observed was planted in early May. Management of stink bugs in vegetative stage soybeans is not typically necessary. As plants enter the reproductive stages of development and pods begin to fill, rescue treatments may be warranted. Growers should consider a rescue treatment when adult bugs or large nymphs reach densities of 1 per foot of row when pods are filling. As soybean fields begin to flower, they can become very attractive to stink bugs.
The holes in the soybean leaves (above photograph) appear to be the work of insect defoliators (e.g. bean leaf beetles). Stink bugs have piercing and sucking mouthparts which they use to remove fluids from plants. Stink bugs may feed on stems, leaves, blossoms, and seeds of soybean plants. They prefer the newest growth and developing seeds. As the season progresses, producers should continue to monitor soybean fields for this insect pest.
Mike Gray, Professor and Extension Entomologist