June 17, 2022
Depending on where you are located and what crop you are growing, you may call it a corn earworm, cotton bollworm or soybean podworm. What’s not up for debate, though, is the damage this pest can do to a crop.
The potential for multiple generations feeding on soybean leaves, flowers and pods is a known threat to soybean yield. Adding a new biological insecticide to the tank with Intrepid Edge® insecticide may boost the control of these yield-robbing worms.
While Intrepid Edge offers fast and lasting broad-spectrum control of worms and loopers, Hearken™ biological insecticide can complement current insect control programs by selectively targeting small tobacco budworm, corn earworm and Old World bollworm.
A targeted viral insecticide for heliothine species, Hearken offers residual control of worms, and control of first to third instar larvae.
Worms feed on the treated foliage and ingest the host-specific pathogenic virus. Once ingested by the larvae, the virus infects young larvae that succumb to the virus and surviving worms that spread the virus to other larvae in the field and can transmit the virus to the next generation.
Deceased larvae also release virus particles that can then infect other larvae of the same species.
In 2021, field studies conducted by Corteva Agriscience and university partners, a tank mix of Intrepid Edge and 0.5 fluid ounce per acre of Hearken demonstrated effective heliothine control in soybeans.
Seven days after a treatment of Intrepid Edge plus Hearken, less than one large larvae remained in the test plot. In comparison, 13 large corn earworm larvae were documented in the untreated test plot.
Infection by the virus, which is a Group 31 baculovirus, can occur even at low-use rates. Recommended use rates range from 0.5 to 2.5 fluid ounces per acre, and applications may be repeated every six to eight sunny days, as needed. The highly selective, natural mode of action does not affect beneficial or nontarget organisms.
To ensure product effectiveness, plant canopy coverage is required because Hearken does not translocate through the soybean plant.
While Hearken is tank-mix compatible with many crop protection products, it should always be added last to the tank. Additionally, the pH of the spray mixture should be between 5 and 8.5, and the addition of a surfactant or adjuvant is highly recommended to increase product coverage.
Hearken should be kept frozen for optimum shelf life and kept refrigerated until time of use.
“Applications of Hearken should be made in the morning or in the evening, when temperatures are cooler,” says Ryan Ridder, biologicals product manager, Corteva Agriscience. “The natural insecticide is a living organism and needs to be stored and applied within the criteria laid out by the product label.”
Hearken should not be applied when temperatures are above 92, as high temperatures can impact product efficacy. Additionally, any tank mix including Hearken should be applied soon after mixing to avoid remaining out in summer temperatures for longer than necessary.
Learn how you can protect your soybean yield from worms and contact your local retailer or Corteva Agriscience territory manager to develop a pest control plan tailored to your farm.
™ ® Trademarks of Corteva Agriscience and its affiliated companies. Hearken™ biological insecticide and Intrepid Edge® insecticide are not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Always read and follow label directions.
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