Corn rootworm caused more than 342 million bushels of yield loss in 2024. That’s over 80 million bushels more than losses from all other invertebrate corn pests combined.¹
It’s a challenging pest to manage. For example: Some corn rootworm species have developed resistance to crop rotation by adapting to lay eggs in soybean fields and leaving larvae behind to infest the following corn crop. Some have also developed resistance to Bt transgenic crops and several classes of insecticides, making diligent and timely management a high priority investment to safeguard yield from what is ominously known as “the billion dollar bug.”
Managing corn rootworm
Traditional crop rotation can still be a powerful tool to prevent infestations of some rootworm species, but western corn rootworm (WCR) and northern corn rootworm (NCR) require a more nuanced approach.
The western corn rootworm’s soybean-laying variant has outsmarted the traditional rotation protocols, while northern corn rootworm eggs can remain unhatched and dormant through two winters via extended diapause, meaning it may be necessary to keep a field out of corn at least two seasons to successfully break NCR’s multi-year lifecycle.
Corn rootworm control strategies
Based on field history, specific corn rootworm species present and localized resistance, an integrated approach using cultural, chemical and seed-based management can help mitigate corn rootworm damage.
Corn rootworm insecticide
If considering chemical options for corn rootworm control, be sure to choose an insecticide effective against corn rootworm populations that have developed resistance to other treatments. Nurizma® Insecticide provides a unique mode of action that protects against belowground pests like corn rootworm larvae, wireworms, white grubs, seed corn maggots and more. It has no cross-resistance with existing modes of action, and its low use rate makes it an efficient corn rootworm insecticide. Specific application rates and timing for Nurizma should be determined with a regional BASF representative.
Cultural management for corn rootworm
Despite the challenges of WCR and NCR variants, rotating to nonhost crops like flax, sunflower, wheat or soybean can effectively disrupt the majority of corn rootworm populations.
Planting corn earlier can also boost root development, earlier silk development and pollination before peak disruption from corn rootworm, lowering the risk of silk clipping and pollination interference by corn rootworm and other beetles.²
Corn hybrids for corn rootworm
Bt corn hybrids with Cry proteins or a combination of multiple proteins can help combat rootworm species. These crystalline proteins selectively kill corn rootworm larvae that feed on the roots of corn Bt hybrids. Bt corn requires alternate planting with non-Bt corn to reduce the acceleration of Bt resistance in corn rootworm and other insect pests.
Follow the corn rootworm monitoring network
The Corn Rootworm IPM is a group of educators and crop specialists from 12 U.S. states and five provinces in Canada, producing yearly summaries of corn rootworm activity, data about dominant species in various locations, and trends in management strategies that may impact the following season.
With a mix of cultural, chemical and seed-based solutions plus careful monitoring, growers can protect crops from the “billion dollar bug.”
Experts are available to help you make decisions on seed, cultural management and corn rootworm insecticides. Reach out to your seed retailer, a nearby extension office agent, or a regional BASF representative.
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Endnotes
- “Corn Invertebrate Loss Estimates from the United States and Ontario, Canada — 2024.” Crop Protection Network, 17 Feb. 2025, cropprotectionnetwork.org/publications/corn-invertebrate-loss-estimates-from-the-united-states-and-ontario-canada-2024. Accessed 22 Jan. 2026.
- Calles-Torrez, Veronica, et al. “Integrated Pest Management of Corn Rootworms in North Dakota.” NDSU Agriculture, 24 Nov. 2025, www.ndsu.edu/agriculture/ag-hub/publications/integrated-pest-management-corn-rootworms-north-dakota. Accessed 22 Jan. 2026.
