Fall Armyworm (Kansas Corn)

Scouting time

Damage from the fall armyworm occurs in midsummer. Larvae chew large holes in whorl-stage leaves. Later, large holes may be chewed into the stalks at the nodes. Control at the whorl stage usually is not practical and should not be attempted unless 75 percent of plants are infested.

Chemical control

Control may be justified on silking-stage corn if small larvae are detected before they have tunneled into the shanks and ears. Where the label allows, the performance of some products may be improved by chemigation. Note that corn hybrids with Herculex I insect protection are advertised to be resistant to fall armyworm damage.



Alpha-cypermethrin (Fastac EC)

 3.2 to 3.8 fl. oz./acre

Beta-cyfluthrin (Baythroid XL)

 0.022 lbs. a.i./acre (2.8 fl. oz.)

Bifenthrin (numerous products)

 0.033 to 0.10 lb. a.i./acre (2.1 to 6.4 fl. oz.)

Chlorantraniliprole (Prevathon)

 14.0 to 20.0 fl. oz./acre

Chlorpyrifos (numerous products)

 Check label, but generally 1 to 2 pints/acre

Chlorpyrifos plus zeta-cypermethrin (Stallion)

 9.25 to 11.75 fl. oz./acre

Cyfluthrin (Tombstone)

 0.044 lb. a.i./acre (2.8 fl. oz.)

Deltamethrin (Delta Gold)

 0.018 to 0.022 lb. a.i./acre (1.5 to 1.9 fl. oz.)

Gamma-cyhalothrin (Proaxis, Declare)

 0.01 to 0.015 lb. a.i./acre (2.56 to 3.84 fl. oz.) (See label for Declare)

Lambda-cyhalothrin (numerous products)

 0.02 to 0.03 lb. a.i./acre

Lambda-cyhalothrin plus chlorantraniliprole (Besiege)

 6.0 to 10.0 fl. oz./acre

Methomyl (Lannate)

 0.225 to 0.45 lbs a.i./acre (12 to 24 fl. oz./acre)

Spinosad (Blackhawk)

 1.67 to 3.3 fl. oz./acre

Zeta-cypermethrin (Mustang MAXX, etc.)

 0.02 to 0.025 lb. a.i./acre (3.2 to 4.0 fl. oz.)

Zeta-cypermethrin + Bifenthrin (Hero)

 4 to 10.3 fl. oz./acre

Content authors


This content may not be suitable for states other than KS.