Army Cutworm (Kansas Wheat)

Scouting time

The army cutworm is a late fall to early spring pest that occurs sporadically in the western two-thirds of Kansas. Infestations are notoriously unpredictable on a field-to-field basis but remarkably high populations have occurred in central Kansas in the past two years. Adult moths lay eggs in soil in the fall. The brown, faintly striped larvae hatch during the fall and early winter. Larvae feed on many plant species, and each adult female can lay more than a thousand eggs. Both factors contribute to the outbreak potential of this species. Larvae begin feeding during the winter whenever temperatures rise a few degrees above freezing. Small larvae strip cells from only one surface of the leaf, creating “windowpane” holes that often go unnoticed unless plants are carefully inspected. Larvae hide in loose soil at the base of plants, emerging to feed in the evening. Unlike other cutworms, only above ground plant parts are consumed, giving plants the appearance of being grazed by cattle.

Sampling method

Infestations in well-established stands will probably not require insecticide applications while wheat is dormant, but some fields never green up in the spring because of cutworm feeding. Frequent inspections during warm periods in February, March, and early April are strongly encouraged, particularly when preceded by a dry fall.


Moisture availability, crop condition, and regrowth potential are all factors influencing potential losses to this pest. Late-planted fields under dry conditions with poor tillering may suffer economic damage with as few as one or two larvae per square foot. In most fields, treatment will not be necessary until populations average four to five worms per square foot. Vigorous, well-tillered fields under optimal growing conditions can tolerate even higher populations, as many as nine or 10 larvae per square foot, without measurable yield loss. Infestations in later stages of crop development are less damaging than early ones because established plants can compensate for considerable defoliation and larvae normally finish feeding before wheat enters reproductive stages.

Chemical control

Armyworm Management Options



Alpha-cypermethrin (Fastac EC)

 1.8 to 3.8 fl. oz./acre

Beta-cyfluthrin (Baythroid XL)

 0.014 to 0.019 lb. a.i./acre (1.8 to 2.4 fl. oz.)

Carbaryl (Sevin 80S)

 1.25 to 1.625 lb./acre

Chlorantraniliprole (Prevathon)

 0.047 to 0.067 lb. a.i. per acre or 14 to 20 fl. oz. per acre

Chlorpyrifos plus gamma-cyhalothrin (Cobalt Advanced)

 11 to 25 fl. oz./acre

Chlorpyrifos plus zeta-cypermethrin (Stallion)

 9.25 to 11.75 fl. oz./acre

Gamma-cyhalothrin (Proaxis)

 0.01 to 0.015 lb. a.i./acre (2.56 to 3.84 fl. oz.)

Lambda-cyhalothrin (Numerous products)

 0.02 to 0.03 lb. a.i./acre

Spinosad (Blackhawk)

 0.025 to 0.050 lb a.i./acre (1.1 to 3.3 fl. oz/acre)

Zeta-cypermethrin (Mustang MAXX, etc.)

 0.011 to 0.025 lb. a.i./acre (1.76 to 4.0 fl. oz.)


Non-chemical controls

None listed.

Content authors


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