Homegrown: They're baaackk; annual battle ensues with Japanese beetles

I knew it was too good to be true.

For almost two weeks this month, I picked raspberries unimpeded.

But mid-June, I had my first Japanese beetle sighting of the season.

The beetles have been the bane of my gardening existence since they first appeared in our yard about a decade ago.

With copper-colored wings and metallic-green heads, the beetles have a striking appearance, but destructive behavior.

They skeletonize the foliage of more than 300 plants and go after berries, including my raspberries, and flowers, such as roses.

Some gardeners use the insecticide, Sevin, or traps that lure the beetles, though I've heard the traps attract more beetles to yards than they capture.

Others have luck with milky spore in the soil, which treats beetles in the grub stage, or with chickens, which devour both grubs and adult Japanese beetles.

My favorite control method is to knock the beetles into a container of soapy water. Dish soap works fine for this.

Japanese beetles have moved westward since Iowa's first infestation was recorded in 1994, and have now been reported in nearly 60 counties from the Mississippi to the Missouri River, according to Iowa State University Extension.

ISU has published a list of the beetles' most- and least-liked plants.

Plants that Japanese beetles tend to ignore include: clematis, forsythia, hickory, pine, holly, red oak, mulberries, juniper and lilac bushes.

Ash trees are another, but experts advise against planting ash because of the risk from emerald ash borer, a foreign pest making its way to Iowa.

Favorite plants of the beetles include grapes, roses, hollyhock, linden trees, pin oak, willows and of course, raspberries.