By Forrest W. Nutter, Jr. and Andrew Gougherty, Department of Plant Pathology; Donald Lewis, Department of Entomology
The Japanese beetle [Popillia japonica (Newman)] first detected in Iowa in 1994, was detected for the first time in six additional counties in Iowa in 2010. Reports from all six counties (Audubon, Carroll, Cherokee, Hamilton, Harrison and Ida) were obtained as part of a Bean pod mottle virus/bean leaf beetle survey funded by the Iowa Soybean Association.
Although less efficient than bean leaf beetle in acquiring and transmitting Bean pod mottle virus, in 2010, Japanese beetles were more abundant than bean leaf beetles in soybean sweep net samples from many Iowa counties. The 2010 reports confirm the presence of Japanese beetles in 52 of 99 counties in Iowa. Samples for the newly reported counties were provided by Iowa State University Extension Field Agronomists Joel DeJong, Mark Licht and Clarke McGrath; Harrison County Extension Program Director Rich Pope; and John Eveland, retired Humboldt County Extension Director.
Figure 1. Updated map showing confirmed distribution of Japanese beetles in Iowa counties in 2010. The 2009 distribution map was published in Horticulture and Home Pest News.
The Bean pod mottle virus/bean leaf beetle survey will be conducted again in 2011. If you find Japanese beetles in a county not marked on the map, please let us know by sending specimens or digital images including capture location and date. Mail to: Plant & Insect Diagnostic Clinic, 327 Bessey Hall, ISU, Ames IA 50011. Email to: firstname.lastname@example.org .
Forrest W. Nutter, Jr. is a professor in the Department of Plant Pathology working on disease risk models for improved disease management. Andrew Gougherty is a research assistant in the Plant Disease Epidemiology Laboratory in the Department of Plant Pathology. Donald Lewis is extension urban entomologist and professor in the Department of Entomology.