Japanese Beetle

Scientific name: Popillia japonica Newman

Native range: Japan

Adult Japanese beetle. Photo by David Cappaert, Michigan State University. forestryimages.org.

At Risk

Many different plants are consumed by Japanese beetle adults, some of their favorites include roses, grapes, apple and basswood. Larvae feed on the roots of grasses and can be a problem for yards and turf. Read about advice on managing Japanese beetle from the University of Minnesota.

Japanese beetle can be a significant landscape pest and difficult to tolerate, particularly when they first become abundant in an area. Since larvae feed primarily on the roots of grass, Japanese beetle is most prevalent in urban environments. However, Japanese beetle can also be a pest in soybeans and other agricultural crops as well.

Contact the MDA if you spot Japanese beetle in areas not known to be infested, or spot large numbers of Japanese beetles in an area where they are not known to be abundant. If possible take a picture or collect a specimen to document the identity of the insects.

Distribution

Japanese beetle is present in most of the eastern United States and has been present in Minnesota for decades. Many people first became aware of Japanese beetle when they were very abundant in the Twin Cities metro area in 2011.

Biology

Adult Japanese beetles become active in Minnesota in late June/early July. Although they are able to eat many different kinds of plants, for anyone who has experienced Japanese beetle, it is clear that they have some plants they prefer over others. Adult beetles can be found congregating on these plants and defoliating them in a manner described as “skeletonizing” because they leave the leaf veins intact but eat all of the tissue from between them. Adult beetles lay eggs in the soil and the larvae live in the soil feeding on the roots of grass until they pupate into adults beetles and emerge the following year.

Identification

Adult Japanese beetles. Photo by Jeff Hahn, University of Minnesota Extension.
Adult Japanese beetles. Photo by Jeff Hahn, University of Minnesota Extension.
apanese beetles feeding on leaves, causing skeletonization. Photo by William Fountain, University of Kentucky, bugwood.org
Japanese beetles feeding on leaves, causing skeletonization. Photo by William Fountain, University of Kentucky, bugwood.org.

Look-Alikes

The most likely thing to be mistaken for Japanese beetle is the false Japanese beetle which is similar but can be distinguished by coloration and the lack of white hair tufts at the posterior end of the abdomen. Rose chafers can also be mistaken for Japanese beetle but lack the white patches of hair along the abdomen entirely.

False Japanese beetle. Photo by Whitney Cranshaw, Colorado State University, bugwood.org
False Japanese beetle. Photo by Whitney Cranshaw, Colorado State University, bugwood.org.
False Japanese beetle compared to Japanese beetle. Photos by Jeff Hahn, University of Minnesota Extension.
False Japanese beetle compared to Japanese beetle. Photos by Jeff Hahn, University of Minnesota Extension.
Rose chafers. Photo by Pennsylvania Department of Conservation and Natural Resources, Forestry Archive, bugwood.org
Rose chafers. Photo by Pennsylvania Department of Conservation and Natural Resources, Forestry Archive, bugwood.org.

 

Pest Status

In Minnesota, Japanese beetle has been found in many counties but is only known to be abundant in some. There are no restrictions related to the movement of Japanese beetle within Minnesota, but there are restrictions related to the movement of Japanese beetle out ofMinnesota.

NEW: Conditions related to movement of plant products that could carry Japanese beetle between states are set by the Japanese Beetle Harmonization Plan which has recently been updated, read about the updated plan.

Japanese Beetle Distribution Map

To access map legend, click on double arrows in the upper left corner. Click on counties for more information.

What Can I Do?

If you think you have an infestation of Japanese beetles, and you're located in a county that Japanese beetle has not been reported or is not known to be abundant (see map above), please visit our Arrest the Pest page to report your findings to the MDA.