Japanese Beetle Emergence Underway Across the State

Reports of Japanese beetles are becoming more common across the state of Illinois. On June 19, Ron Hines observed his first Japanese beetles of the season in Massac County. Much further to the north, Angie Peltier, University of Illinois Extension Commercial Agriculture Educator located at the Research and Demonstration Center, Monmouth, Illinois, collected about 1 inch of beetles in a trap from June 20 to 24. These observations confirm that this perennial insect pest of corn and soybeans is present throughout much of  the state. Thresholds for soybeans are based upon defoliation levels (30% before bloom, 20% between bloom and pod fill). For corn, as we move into the reproductive phase of growth and development next month, producers will need to pay attention to the level of silk clipping that is occurring. At this point in the season, it’s still too early to tell how numerous this insect will be in 2013.

Mike Gray