Root Smells Draw Pest Beetles When Corn Is Chewed

In the soil below a corn plant, tiny chemicals called small lipophilic molecules can change how insects behave. Scientists wanted to see if eating corn leaves and roots at the same time would make these chemicals more attractive to a common pest, the wireworm. They grew corn in pots and exposed it to leaf‑cutting moths, root‑bored wireworms, or both. They then collected the gases that came from the roots and mixed them in a lab.

When wireworms smelled only one type of plant chemistry, they were not very interested. But when the root gases came from a corn plant that had been eaten on both leaves and roots, the beetles were drawn in strongly. The researchers also made a synthetic mix that mimicked this “dual‑damage” scent and tested it outdoors. The beetles again followed the smell back to the roots. These experiments show that a plant’s scent can change depending on where it is attacked, and those changes can lure pests from the soil. The study helps explain why some crops get worse when both above‑ground and below‑ground insects are present, and it suggests new ways to protect plants by manipulating root odors.

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