JUNE 25, 2015
nchris@iastate.edu
Here is a post from Dr. Donald Lewis, entomologist at Iowa State University. In recent weeks, we have both been contacted about Japanes beetles (Popillia japonica) showing up in central Iowa. Don has found that these are actually False Japanese beetles (Strigoderma arbicola). We do get Japanese beetles here, although last year populations were low.
Here is Don's post.
From: Lewis, Donald R
[ENT]
Pest identification is a keystone to IPM. An example going
on now is the emergence of False Japanese Beetles (FJB) in eastern and central
Iowa. As the name implies, false Japanese beetle (Strigoderma arbicola)
is very similar in appearance to the true Japanese beetle. The major
difference is the coloration. False Japanese beetles do not have the
bright green and copper coloration of the Japanese beetle. They are dark
tan to brown though the thorax may appear metallic green on some
specimens. False Japanese beetles do not have the five white hair tufts
that are prominent on each side of the abdomen of the Japanese beetle.
Here is a link to a close-up photo of FJB where these characteristics can
be viewed.
The BugGuide website uses the common name “sand chafer” which
matches very well the locations where we must commonly see this beetle in
fields, gardens and lawns. However, the common name “false Japanese
beetle” has been used in Iowa for at least the past 50 years! The False
Japanese Beetle is moderately common in the state but varies greatly from year
to year. Others are reporting more than usual this year.
Technical information about false Japanese beetle: http://bugguide.net/node/view/44690
An old article about FJB: http://www.ipm.iastate.edu/ipm/hortnews/1999/7-2-1999/fjapbeet.html
Note since 1999 the true Japanese beetle has expanded its range in Iowa to 63
counties (not the 5 listed in the chart).
Thanks.
Donald Lewis
Donald
R. Lewis
Professor
Department
of Entomology
Iowa
State University
Ames
IA 50011