Since launching insect-protected corn rootworm traits in 2003, Monsanto has periodically documented pockets of heavy corn rootworm infestation, especially in geographies with a long history of corn-on-corn plantings. Farmers in these areas may see intense rootworm pressure that can overwhelm rootworm-protected corn plants, leading to performance inquiries. 

We continue to work with farmers, academics, the Environmental Protection Agency, and other key stakeholders to understand why trait performance is less than expected on these fields and to provide sound agronomic solutions. We work collaboratively to ensure that modern insect-protection tools, such as Bt traits, remain useful to farmers for years to come.

Our Recommendations

For those fields with greater than expected corn rootworm damage, we recommend the implementation of very specific best management practices (BMPs). 

These BMPs provide practical solutions to reduce rootworm populations, limit rootworm damage, and enable insect resistance management. The BMPs are as follows:

• Rotate to a non-host crop such as soybeans to break the CRW life cycle. Periodic rotation provides a number of benefits in addition to effective CRW control.
• Plant Genuity^® SmartStax^® RIB Complete^® Corn Blend products that provide dual mode-of-action (pyramided) Bt traits and deliver excellent CRW protection.
• If rotation or Genuity^® SmartStax^® RIB Complete^® Corn Blend products are not acceptable options, consider using soil-applied insecticides in combination with hybrids that do not provide Bt protection from CRW. 

Regardless of which primary control tactic listed above is implemented, growers should adopt the following support activities to maximize success:

• Scout the crop regularly throughout the growing season collecting relevant information regarding insects throughout their lifecycle.
• Use foliar insecticides and chemigation rescue treatments according to established thresholds.
• Control volunteer corn and weedy escapes in rotational crops. These plants may attract beetles and encourage concentrated egg-laying within the non-host crop.
• Read, follow, and understand, the IRM Grower Guide for all Bt technologies prior to planting and observe all refuge requirements.