Thursday

Control Japanese Beetles Naturally

You don't necessarily need to stock up on traps and pesticides to control Japanese beetles, but you do have to have good timing and a plan. To beat these bugs, you need to be as cagey and as persistent as they are.  There's a natural approach, but it isn't magic.  It takes catching them early and using their scent as a deterrent. The good news is that this approach is relatively easy and inexpensive.

Natural Japanese Beetle Control


The first step is to take some precautions: Japanese beetles are attracted to diseased plants and trees. The cleaner you keep your garden, the better. This is particularly true when Japanese beetles first become active in your area.  Their emergence is predictable in the neighborhoods they inhabit, occurring during the same couple of weeks every year. If you've had an ongoing struggle with Japanese beetles, you probably know their schedule by heart.  If not, contact your local Cooperative Extension Office or ask at your local nursery. 

Before they emerge is the time for general yard cleanup. Get rid of any rotting wood lying around your property, dispose of dead plants and shrubs and bag dead leaves and general debris like dry grass. They also like windfall fruit from peaches and other early summer fruiting trees.

Deal With the Problem Early in the Season


Japanese beetles send out scouts to investigate the best feeding grounds. They scent mark locations that look promising, and other beetles move in soon after. What looks promising to a Japanese beetle is the presence of plants it enjoys eating.  Eliminate those plants and you're less likely to have a problem. 

The bad news is that these bugs aren't very discriminating. They like lots of different plants, shrubs and trees.  For a good list of their favorites, visit my post: What You Need to Know about Getting Rid of Japanese Beetles.  If you're designing or redesigning your landscape, maintaining fewer of these species in Japanese beetle infested areas will save you time and effort.

Beating Japanese Beetles at Their Own Game

Japanese Beetles' rely heavy on scent, and you can use that as a weapon against them. Here's how:

Kill the first Japanese beetles you see in your garden. It's important that you catch them early, so keep a close watch. They regularly appear during the second week of June in my area. You may be a few weeks ahead or behind that schedule.  When you see a few beetles, get to work:

  1. Fill a bucket about half full of water.
  2. Add a quarter of a cup of dish soap. (The amount of soap isn't that critical as long as it's present.)
  3. Snag beetles with you gloved hands and place them in the bucket.  If touching them doesn't appeal to you, you can knock them into the bucket by giving the branch they're on a quick shake. This could take some practice.
  4. Leave the beetles in the bucket. They'll die and begin decomposing.  The smell will deter other beetles, and the presence of soap will discourage or kill mosquitoes. (The bucket will only smell nasty to beetles.)
  5. Set the bucket in an area where you've had bad infestations before, or select a spot that gets good airflow.

In doing this, you're letting new beetles know that the area is off limits. Think of it as the beetle equivalent of razor wire.  Leave the bucket in place for at least a two to three weeks, adding to it every couple of days. You'll see beetle activity slowly diminish over that time.  If you start this procedure too late in spring, it won't work nearly as well -- if at all. 

Japanese Beetle Traps May Not Be a Useful Option

You hear a lot about traps and natural predators as options for controlling Japanese beetles, but the best method is to avoid making your property attractive to them. If you discourage them early enough in the year, Japanese beetles will bypass your garden in favor of more appealing real estate. Once entrenched, they are less likely to come back to your garden in destructive numbers. If you start seeing an increase in activity, kill more beetles and place them in another prepared bucket.

If you wait too long, beetles will settle in, breeding on your property and making more problems you'll have to deal with next year. If this happens, there are other methods you can use to eradicate these pests, especially if you have a large or long standing problem with them in your landscape.  Here are some options:

  • Put down milky spore.
  • Use nematodes.
  • Try insecticidal soaps.
  • Resort to using insecticides.

You can read more about these options in the post I referenced above: What You Need to Know About Getting Rid of Japanese Beetles


Reference

Photo1 - JapaneseBeetles1Wiki.jpg By User:SB_Johnny (Own work) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-SA-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons http://upload.wikimedia.org/wikipedia/commons/2/20/Japanese_Beetles_on_rose.JPG http://commons.wikimedia.org/wiki/File%3AJapanese_Beetles_on_rose.JPG

Photo2 - JapaneseBeetles2Wiki.jpg Lamba at the Italian language Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)], from Wikimedia Commons http://upload.wikimedia.org/wikipedia/commons/0/06/Popillia_japonica_-_Japanese_beetle.JPG http://commons.wikimedia.org/wiki/File%3APopillia_japonica_-_Japanese_beetle.JPG

2 comments:

  1. The soapy water works. My method is a little different. I half-way fill a plastic bowl (soft spread margarine or whipped topping) with water and a few drops of dish soap. I also fill a spray bottle with the same solution. Shaking the branches over the bowl often causes the Japanese beetles to escape, so I spray them first with the spray bottle. With soap in their eyes and on their wings they don't immediately fly away, giving you time to knock them into the soapy water solution in the bowl or to pick them off before they fly away. Using several bowls allows you to spread them out increasing the effectiveness of the dead bug scent as a deterrent.

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    Replies
    1. Tiffany,

      Great ideas! Thanks for sharing.

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