Pale western cutworm larvae are subterranean and feed on plants below the soil surface. Because pale western cutworms cut stems, if the growing point is destroyed, the plants cannot recover from damage. Pale western cutworm infestation results in stand reduction. Damage appears as dead or wilted tillers or plants. As mentioned earlier, moisture can influence cutworm mortality.
Records indicate that soil packing from compaction also forces larvae to soil surface.
Decision-making Guidelines Early detection of damaging cutworm populations is critical. Fields should be monitored periodically beginning in late winter or early spring for cutworm larvae. Treatment thresholds are directly related to the health and vigor of the growing crop. If the crop is experiencing moisture stress then the effects of cutworm damage will be more dramatic. If plants are not drought stressed and appear healthy and vigorous then insecticide treatment is justified when there are 4 to 5 army cutworm larvae per square foot.