Pesticide Free Japanese Beetle Defense

Looking for a mate or a meal in the corn patch

They're Here...
As I walked through my yard tonight I found them. 
I had heard others talking about them, but had only seen one or two so far this year.  Now they are in my backyard.  Two years ago I had tons of them and they did quite a number on my apple trees,
and seriously denuded our cherry.  Last year I
was pretty vigilant, but they didn't seem as bad.  Only time will tell for this year...



Japanese Beetle on a Peach Tree Leaf

 
What are they?
Japanese Beetles are an iridescent copper and green colored beetle, about 1/2" long.  They would be quite beautiful if they weren't quite so destructive.  They eat the leaves of your plants, leaving the skeletonized veins behind.  This kills the leaf and hinders its ability to perform photosynthesis (using the sun's energy to make sugar, energy for the plant).

Controlling Them
Adult beetles are difficult to control.  There are certain nematodes and bacterial products that over time can control the larvae in your yard.  The problem is the ones eating your plants may not be from your yard.  The Japanese Beetle has an acute sense of smell and can be attracted from long distances in its search for a mate.  There are also traps that use these pheromones to attract and trap them.  I have not tried these because I don't want to attract any more than I already have, and from what I've read that is what they do. 



Fresh tonight, not stinky yet

What works best for me is to add some dishsoap and water to an ice cream bucket.  The bucket is large enough to catch them in, and the soapy water coats them with a film that they cannot breathe through.  The beetles are poor flyers and usually drop from the leaves when disturbed.  I take the bucket, hold it under a leaf or group of leaves with the biggest collection of beetles, and give it a shake.  The stubborn ones may need a finger flick to be convinced to take a swim.  Be careful not to shake the branch too much or the others on the tree/plant may fly away before you get them.  This seems to be a good way to catch large bunches of them. 

But here's where it gets sort of gross.  I figured since they are so attracted to the smell of living ones, would they be repelled from the smell of dead and rotting ones?  The idea may have come to me because I once left a bucket for a few days in the garden with dead ones in it.  Leaving the stinky bucket near plants that are the Japanese Beetles' favorites has seemed to keep them away!  I have also tried to protect several trees, by dipping some of the mass of dead beetles out of the bucket and around the base of the trees I want to protect.

Maybe it should be higher?

Integrated Pest Management
I also put up a wren house this year that I built out of some scrap lumber.    Plans can be found many places on the internet.  I modified these to be able to use what I had for leftover wood.  I have heard of these little songbirds being quite fond of the pesky beetles.  Unfortunately, we didn't get any to nest in it this year, maybe next year.







More Tips
Also if you are planning new landscape plantings here is a list of plants the are favorite foods and not so favorite foods of our pretty little pests.
Courtesy of http://www.ipm.iastate.edu/ipm/hortnews/2010/7-14/japanesebeetle.html 

Least Favored By Japanese Beetles	Most Favored by Japanese beetles
Arbovitae Boxelder Boxwood Clematis Dogwood* Euonymus sp. (burning bush, etc.) Forsythia Hemlock Hickory Holly Juniper Lilac Magnolia Mulberry Northern red oak Pine** Red and silver maples Redbud Spruce*** Sweet gum Tulip poplar (tuliptree) Yew	American and English elm Birch Black walnut Elm Grape Hawthorn Hollyhock Horse-chestnut Japanese* and Norway maple Larch Linden London planetree Malus spp. (crabapple, apple etc.) Mountain ash* Pin oak* Prunus spp. (flowering cherry, etc.) Pussy willow Rose Raspberry Virginia creeper Willow

  * May not be hardy or perform well throughout Iowa.

** Scots and Austrian Pine are not recommended because of disease problems.
*** We do not recommend blue spruce because of disease problems