Issue No. 11, Article 2/June 17, 2010
Japanese Beetle "Season" Has Begun
On June 7, Ron Hines observed Japanese beetles on corn plants in Massac County. He also has noticed Japanese beetles feeding on several flowering shrubs in his yard. Although sightings of Japanese beetles have been less common in central Illinois, they will become more numerous over the next week to 10 days. If the rains stop long enough for field visits to begin again, don't be surprised to see densities of this insect pest increase. I believe survival through the winter should have been good for the grubs, and the early planting and root establishment will enhance the prospects for moderate to high populations of Japanese beetle adults this summer.
Japanese beetle adult on rose of sharon shrub, June 9, Massac County. (Photo courtesy of Ron Hines.)
When scouting for adults in corn or soybean fields, be sure to move beyond the border rows. Research conducted in 2009 by Andy Morehouse, graduate student in the Department of Crop Sciences, indicates there are considerable differences in adult densities between the interior of fields and border rows. If you're finding Japanese beetle adults in your area of the state, I would be interested in hearing from you; I will share the observations with readers of the Bulletin.--Mike Gray