Bt-corn fields near Lake Campbell, Bruce, Milbank, Baltic, and Colman, S.D., exhibited surprising signs of corn root worm damage last year and South Dakota State University extension entomologists want to learn how more about the problem.

"Not all problem fields are reported; therefore, it is difficult to quantify whether these are isolated instances or represent a potential broader scale occurrence," reports says Ada Szczepaniec, SDSU assistant professor and extension entomologist. "In those fields that have been investigated, resistance to Bt hybrids has not been confirmed yet, and we will work to collect data to test this next year."

Are Resistant Corn Rootworm In S.D.?

Fields with a history of at least three years of continuous corn with the same Bt hybrid are at the greatest risk of having Bt-resistant populations of corn rootworms.

"Corn rootworm issues in fields planted with Bt-corn hybrids have been getting a fair amount of attention in the Midwest and Northern Plains. Because South Dakota has a substantial diversity of soil types and growing conditions, it is likely that the severity of corn rootworm issues varies significantly within the state," she says.

Szczepaniec is asking South Dakota corn growers to help collect the needed data by filling out a short, online survey which SDSU Extension staff will use to develop research-based recommendations to aid the state's corn growers deal with this pest.

"The survey will take only a minute or two to complete, and it will provide us with invaluable information on the needs of corn producers in the state. Knowledge of the locations and scope of corn rootworm issues will enable us to prepare customized extension resources based on specific needs of the corn producers in the state," Szczepaniec says.

To complete the survey, please go to here.

Source: SDSU