black cutworm lateral MER copy.jpg

Black cutworm

Description

  • Adult: Moth that is dark gray with a black, dagger-shaped mark on the outer forewing and dark inner forewings with a wingspan of 1½".
  • Larvae: Worms are light gray to black and about 1½" long when mature. Covered in convex skin granules, which gives them a shiny and greasy appearance.
  • Eggs: White ribbed globules in clusters of 10 to 30 near food sources.
     

Timing of damage: VE to V8

Type of damage: Leaf feeding and stalk cutting.

Scouting: Scout fields early. Check at least 50 plants in each of five locations. When injured plants are found, dig around the base for cutworms. Note the number and size of larvae found per 100 plants, the percentage of damaged plants and the plant stage.

Economic threshold: When 3% of the plants are cut and larvae are still present (at least 2 per
100 plants).

Similar Pests

Ask an Agronomist