This is a continuation of a collaboration with Drs. Jason Bond and Ahmad Fakhoury at Southern Illinois University to survey insect and disease pests that injure soybean stems. Our focus at UIUC has been on two insect pests: dectes stem borer and the potentially invasive soybean gall midge. During the first three years of this project, we have surveyed the state (with a special emphasis on southern Illinois) for dectes stem borer adults and larval stem tunneling. In addition, we have included a detection survey for the soybean gall midge in the existing Statewide Insect Pest Survey in an effort to confirm in the state early should it arrive here. (To date, this insect has not been found in Illinois).

During Year 4 of this project, we will continue to survey dectes stem borer adults and look for soybean gall midge in the Statewide Insect Pest Survey. This survey includes soybean fields in 4-5 counties from each of the 9 Crop Reporting Districts in the state, providing a statewide assessment of the distribution of dectes stem borer and broad detection ability for the soybean gall midge should it arrive here.

The broader project (including PIs from SIU) will result in improved understanding of the impacts of insect and disease pests that attack stems on soybean yield and quality. Our portion of the project is focused on dectes stem borer and soybean gall midge. Our survey will facilitate early detection of soybean gall midge should it ultimately end up in Illinois, improving our ability to respond to this potential invasive pest rapidly.

With dectes stem borer, we seek to better understand the distribution and relationship with yield loss of an insect that has received little attention in Illinois until relatively recently. Examining the timing of dectes stem borer development and injury to soybean could clarify why, despite injury to the vascular tissue of the stem, yield losses are typically minimal or nonexistent unless lodging of plants occurs. Better understanding the timing of larval injury relative to seed fill could reveal scenarios where physiological yield loss is likely to occur.

For example, if soybean gall midge were found, we could notify farmers in the affected area to inform them of the new risk of this pest, conduct workshops on identification and management of this insect, or even attempt local eradication depending on the circumstance.