armyworm lateral MER copy.jpg

Armyworm (corn)


  • Adult: Moth that is about 1" long with a 1½" wingspan. Tan or light brown with a small white spot in the center of each forewing.
  • Larvae: A worm that is dark greenish brown to black with long orange, white and brown stripes running the length of its abdomen. One and a half inches long when mature and have a yellow-brown mottled head.
  • Eggs: Small white globules laid in rows or groups on the lower leaves of plants.

Timing of damage: VE to V12

Type of damage: Leaf margins, and sometimes the entire leaf, will be stripped.

Scouting: Examine 20 plants in each of five locations to determine the percentage of damaged plants. Note the size and number of larvae found.

Economic threshold: In seedling corn, treat when 25% of plants are damaged. After pollen shed, treat when feeding occurs above ear level.

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