How Do I Get Rid of This Terrible Pest?

by Sandy Swegel

I was so late writing my blog post this morning because I foolishly strolled out into the rose garden, where everything was delightfully dewy and fresh from rains last night.  I thought I would deadhead a few late season roses that looked spent.  As I got close, I was puzzled about how beat up the rose blossoms were and wondered if the rains had been excessive.  Then I saw the glint of iridescent green and saw my first ever Japanese beetle. Now I know what gardeners in the East have known for a long time.  This is a terrible pest.  The destruction on flowers and foliage was dramatic since I was last in the garden three days ago. I spent the next solid hour hand picking the beetles and dropping them in a bucket of soapy water.  There were as many as six eating a single blossom.  I could look at a plant two feet away and see one on every top leaf. And I swear they were mating and eating at the same time.

Colorado has generally not had a Japanese beetle problem.  It wasn’t till about 2009 that the state ag department reported some in pockets of south Denver.  I was living in ignorant bliss.  I don’t understand how we went from no beetles in my area to hundreds in my rose garden alone.  Handpicking will clearly not be enough, but most of the pesticides I’ve read about would also kill bees and beneficial insects.

Do any of you know of successful controls?  I’ve googled treatments but haven’t found much info on what might really work in eradicating them.  We’ve actually been kinda happy around here about warming trends.  A slightly shorter winter didn’t seem like such a bad thing when you’re in the foothills of Colorado. But now the pests that we’re getting that also appreciate the warming trend is not worth warmer days in April.  How do I have a pretty organic garden with Japanese beetles?

http://www.ext.colostate.edu/pubs/insect/05601.html