Southern Corn Leaf Beetle

Pest ID

Southern Corn Leaf Beetle

  • Southern corn leaf beetles are small (1/4 inch long), dark brown and are often covered in soil particles.
  • Facts

    • As the corn grows, the beetles will eat into the side of the whorl about 1 inch above the soil surface and the plant will bend over, trapping the new leaves.
    • Adults feed on stem and leaf tissues of seedling corn plants.
    • Injured corn plants are ragged because of the notched out leaves.
    • If disturbed, they will drop off the plant onto the soil and become more difficult to find.

    Life Cycle

  • Adults overwinter beneath soil and plant debris and in clumps of some species of weeds.
  • In the spring, the adults emerge and begin to feed on plants such as cocklebur and early-planted corn.
  • Females lay eggs in clusters of 10 to 50 in weed debris or in the soil at the bases of corn plants.
  • In a week to 10 days, the larvae hatch and begin to feed on corn roots.
  • The larval period lasts for approximately 10 weeks and occurs from early May until mid-July in the central portion of the Corn Belt.
  • Adults emerge from the soil beginning in mid-July and after a limited feeding period, begin to secure their overwintering site. The adults are strong fliers and movement from field to field is common. (SOURCE: Southern Corn Leaf Beetles Are Active in Western Illinois, May 8, 2003, Kevin Steffey)
  • Management

  • Scouting for southern corn leaf beetle is effective and a postemerge insecticide works well and can be tank-mixed with a herbicide.
  •