Corn Rootworm Management
A yearly scouting program is the first step to effective management, because corn rootworms can rebuild their populations rapidly. Monitor larvae and adult beetle numbers to predict potential egg laying and future problems. The level of rootworm feeding and beetle activity will determine the best management options. Incorporate several of these options to effectively control CRW with an integrated approach.
"Consider an insecticide treatment if the number of beetles averages 0.75 or more per plant and 10% of females are gravid with eggs."
- Can reduce corn rootworm pressure.
- Ineffective in areas with soybean variant WCRW that lay eggs in non-corn fields or variant NCRW in which eggs may remain in the soil for several years before hatching (extended diapause).
Suppress Larval Development
- Use a granular or seed applied insecticide at planting.
- Plant a product with multiple modes of action of control against CRW, such as Optimum® AcreMax® Xtreme or Qrome® products.
- Consider using a CRW Bt-traited product with Poncho® 1250 + VOTiVO® insecticide seed treatment for additional protection.
- Applying a soil-applied insecticide in addition to using a CRW Bt-traited product is not recommended for control of CRW except in limited circumstances. Consult with your Pioneer sales professional, university extension, or other local experts for further guidance.
Control CRW Beetles with Insecticides
- A well-timed foliar insecticide application can effectively reduce gravid egg-laying beetles.
Be sure to alternate modes of action when using insecticides. When using corn hybrids that contain Bt traits for corn rootworm control, it is essential that refuge acre requirements are followed. Failure to comply with refuge requirements and lack of control of adult beetles within the refuge acres will only accelerate the pest’s ability to develop resistance.
Areas with high numbers of adult corn rootworms should consider incorporating a beetle suppression program that utilizes foliar-applied insecticides. This should help reduce the amount of egg laying and potential problems in the future.