New Corn Variety May Reduce Crop Losses from Earworms

By Blake Jackson

Penn State researchers have discovered that certain corn varieties possess inherent insecticidal properties, offering a potential solution to combat corn earworm damage, which causes significant crop losses annually. This research is particularly relevant given the increasing threat of pest damage due to extreme weather.

The researchers found that corn lines with high levels of flavonoids - compounds involved in plant defense - significantly impacted corn earworm larvae.

Larvae feeding on these flavonoid-rich corn silks, husks, and kernels exhibited slower growth and increased mortality compared to those feeding on corn lines lacking flavonoids.

The study also revealed a “leaky-gut-like syndrome” in the larvae, suggesting changes in their gut microbiome. Gene expression related to gut health was also altered in larvae consuming the high-flavonoid husks.

The research team compared larvae survival rates on genetically identical corn strains, differing only in flavonoid expression.

The corn, grown at Penn State’s Russell E. Larson Agricultural Research Center, included a genetically engineered line and a conventionally bred line, both designed to produce high levels of flavonoids. The conventionally bred line was developed over two decades by cross breeding a mutant corn line.

“This research is important because it may be an early step toward the development of corn lines resistant to insect pests ideal for organic production,” said research team leader Surinder Chopra, professor of maize genetics. “These findings, which suggest a novel option for integrated pest management for corn earworm larvae, shows that high-flavonoid maize has the potential to be used in a breeding program to develop specialty corn lines tolerant of multiple insect pests.”

The researchers observed a “stark difference” in larval mortality and weight between the high-flavonoid lines and the control lines. Both the genetically engineered and conventionally bred lines had similar effects on the larvae.

Chopra noted that further research is needed before plant breeders can develop flavonoid-producing corn lines that are resistant to a wider range of insects, particularly for organic farming.

“Future studies will investigate the mechanisms behind flavonoid-mediated damage to the gut of corn earworm larvae and will explore the broader impacts of flavonoid content on plant-insect interactions,” he said.

Photo Credit: gettyimages-awakr10