2021 saw root injury and lodging caused by the feeding of corn rootworm larvae in many Minnesota fields. The resulting rootworm beetle populations were also high.
Western corn rootworm populations and root injury appeared to be larger in continuous corn, particularly in geographic areas where a large proportion of fields were planted to long-term continuous corn. Northern corn rootworms and extended diapause populations in rotated corn also increased.
What will rootworm populations do during 2022? Did the winter influence western corn rootworm populations? Are populations increasing or decreasing? Scouting beetles will help provide an estimate of the risk for problems in the following corn crop. Aggregate data from numerous fields across multiple areas of Minnesota can provide clues on changes in rootworm populations over time.
We will once again be collating rootworm data from yellow sticky traps placed in cornfields across Minnesota during late July-August. There is also an opportunity to include your data in a multi-state database.
The cooperative corn rootworm trapping project can supply traps to cooperators. If you would like to participate, please contact me if you have not already done so (email@example.com or 507-276-1184).
This project is supported, in part, by the farm families of Minnesota and their corn checkoff investment.