Army cutworms had been detected on some Kansas wheat fields as of mid-March, says Jeff Whitworth, Kansas State University research and extension entomologist. Alfalfa may also be affected. "First-year fall-planted fields are the most susceptible," Whitworth explains. "However, foliage feeding in established stands may reduce yields, especially in the first cutting. Treat first-year fields when there is an average of two or more larvae per square foot. Established stands should be treated when there is an average of four or more larvae per square foot."
Army cutworms spend summers in the Rocky Mountains, Whitworth says. They fly back to Kansas and surrounding areas in the fall and lay eggs in the soil. The eggs hatch either in the fall or early winter. "Last fall, some early instar larvae were found in Kansas, indicating that populations this spring could be expected," he says. Larvae begin feeding when temperatures rise a few degrees above freezing.
Source: Kansas State University.