Black cutworm moth captures have started to show up across parts of Missouri, which is a sign that spring has officially arrived—not just for us, but for some of our early-season insect pests as well. Moth captures were reported from multiple locations through the Missouri IPM Pest Monitoring Network. Traps were deployed statewide in early March, and pest monitoring alerts are sent by e-mail to subscribers when pest captures reach significant numbers. While moth captures in a pheromone trap do not indicate that treatment is necessary, they help inform growers and agricultural specialists that it is time to start scouting fields.
Early-season black cutworm infestations result from moths migrating northward from southern regions. Following arrival, females lay eggs during warm nights, often in fields with crop residue, winter annual weeds, or low, poorly drained areas. Larvae initially feed on leaf tissue but become more destructive as they develop. Larger larvae can cut corn seedlings at or below the soil surface, resulting in stand loss. The first generation is typically the most damaging in Missouri, particularly when environmental conditions delay crop growth.
Figure 1 A. Black cutworm moth captured in a pheromone trap in Columbia, MO (Photo: Ivair Valmorbida). B. Black cutworm larva and cutting damage to corn (Photo: W.M. Hantsbarger, Bugwood.org).
As of March 31, 2026, monitoring reports from the University of Missouri Pest Monitoring Network indicate black cutworm moth activity in several counties, including Linn, Ralls, Holt, Boone, and Stoddard. In Missouri, pest alerts are triggered when black cutworm moth captures exceed threshold levels (e.g., ≥5 moths in a bucket trap). Degree-day accumulation (base 50°F) from this point can be used to predict larval development and when black cutworm larval cutting is likely to begin. Cutting injury is typically expected to begin after approximately 300 degree-days have accumulated, with current projections indicating potential cutting in late April to early May. However, this procedure does not predict the severity of damage in individual fields, which must be determined by scouting.
Black cutworm larvae can cause significant injury to corn by cutting plants at or below the soil surface, particularly from emergence through the V5 growth stage. Economic thresholds are based on plant damage and larval presence. Treatment is generally recommended when 2–4% of plants are cut below ground, or 6-8% of plants are cut above ground, and larvae are still present. Regular scouting is essential to assess black cutworm larval activity and determine if management is warranted.