New Stink Bug Species May Show Up In Illinois Soybean Fields: Scout Vigilantly

URBANA, ILL.
   Illinois producers are familiar with the green stink bug (Acrosternum hilare) and brown stink bug (Euschistus servus) species. Stink bugs are attracted to soybean plants in the bloom to early pod-fill stages. They use their piercing and sucking mouthparts to remove plant fluids, injuring tender plant tissues, especially developing seeds. For this reason, they are capable of causing economic losses to soybeans, and an economic threshold of 1 bug per row foot during the podfill stage has been suggested. Over the past several years, other stink bug species have become more numerous in soybean production areas of the southeastern United States, including the red banded stink bug (Piezodorus guildinii Westwood) and the red shouldered stink bug (Thyanta custator custator Fabricius).
   The red banded stink bug has been observed in states including Arkansas, Louisiana, Mississippi, Missouri, and Tennessee and has been reported to cause significant management challenges, particularly in Louisiana, where densities have reached economic levels in certain years. Thus far, the red banded stink bug has been reported to show up in southeastern Arkansas late in the season, and late-maturing soybeans are at greatest risk. Although the red shouldered stink bug has been reported in several southeastern states as well, it is described as easier to manage. The suggested economic threshold for the red banded stink bug is 24 insects per 100 sweeps. This compares with a threshold of 36 insects per 100 sweeps for the brown stink bug.
   In addition to these stink bug species, producers should be alert for the brown marmorated stink bug (Halyomorpha halys). This species has been reported in many states, including Illinois, and is considered a potential pest of some species of shade and fruit trees, vegetables, and legumes (including soybeans).
   On July 12, Patricia Stoller, a teaching associate in the Department of Crop Sciences, sent me a photograph of a stink bug she saw just south of Champaign, near the Cruse Farm. The stink bug looks very similar to a red shouldered stink bug, but we could not confirm the species identification because we didn’t have the actual specimen and couldn’t observe its ventral (lower) surface.
   Nonetheless, I am encouraging producers to be vigilant and report any stink bug species that resembles the red shouldered, red banded, or marmorated stink bug in their soybean fields this summer. Suspicious stink bugs should be reported to Kelly Estes, State Survey Coordinator, Illinois Cooperative Agricultural Pest Survey Program (217-333-1005); or send an e-mail to invasives@inhs.illinois.edu. Δ
   DR. MIKE GRAY: Professor Crop Production, Integrated Pest Management, University of Illinois

Unidentified stink bug species found south of Champaign on July 10. Photo courtesy of Patricia Stoller