University of Illinois

No. 11/June 5, 1998

If You Have Time, Look for Cereal Leaf Beetles in Wheat

Mike Roegge, Extension crop systems educator in Quincy, reported finding cereal leaf beetle larvae feeding on 30 to 40 percent of the flag leaves in a few wheat fields in Adams County. We discussed cereal leaf beetles in issue no. 7 (May 8, 1998) of this Bulletin, but some of the information bears repeating.

A cereal leaf beetle larva resembles a slug or a small glob of mud. This "glob" is an accumulation of fecal matter carried around by the immature cereal leaf beetle. The larvae feed upon the green epidermal tissue of leaves, causing injured leaves to appear silver. Severely damaged fields look "frosted." Severe damage to the flag leaf can reduce yields by 25 to 30 percent. An insecticide treatment may be justified when the combination of eggs and larvae average three or more per stem.

Insecticides suggested for control of cereal leaf beetles in wheat are Sevin XLR Plus at 2 pt per acre and *Warrior 1EC at 2.56 to 3.84 oz per acre. Warrior is a restricted-use pesticide. Please follow all label directions and precautions. Also, please note that the harvest interval for Sevin is 21 days between application and harvest, and the harvest interval for Warrior is 30 days between application and harvest.

Kevin Steffey (, Extension Entomology, (217)333-6652