The below is from the University of Kentucky about JB traps in general:

"Research conducted at the University of Kentucky has shown that the traps attract many more beetles than are actually caught. Consequently, susceptible plants along the flight path of the beetles and in the vicinity of traps are likely to suffer much more damage than if no traps are used at all. In most landscape situations, use of Japanese beetle traps probably will do more harm than good. If you experiment with traps, be sure to place them well away from gardens and landscape plants."

I would use great caution. Maureen

I agree with Maureen. I personally believe that the traps attract more to the area than those that would naturally be attracted to the plants. When I see my neighbors put them out, I CRINGE. I then try to use my persuasive skills to convince them to discard them. IÂve found insecticidal soap, such as the Safer Brand helps limit the population. The trick is to hit them with the soap when they are on the leaves. Or you could always pick them off by hand..:)

I don't like touching bugs, so when I see them I head out with a container of soapy water - only a slight amount of soap is needed. I hold the container below the bugs and tap or smack the foliage, forcing the beetle down into the soap. For real effectiveness this has to be done in the morning - the beetles are truly sluggish at that time. It works very well. Maureen

The Japanese Beetle traps emit a pheromone, an odor similar to that which a female JB ready to mate emits, which attracts the male JBs. They emit a pheromone, an odor that attracts the female Japanese Beetles, so when you place those traps in your yard you are calling out to all the JBs in the world "come visit my yard".
The best way to keep these wee critters from you garden is to work on your soil and make it into a good, healthy soil that will grow strong and healthy plants that are less atractive to the insect pests of the world.

kimmsr, you are so right. Maureen

Well I bought a Bag a Bug today at Home Depot which I will promptly return tomorrow!

I wondered why the instructions stated that you should place it downwind from the plants that you are trying to protect and the wonderful advice here explains just that. I certainly don't want to continue to attract them, much less in larger nubmers than I already have.

I'll try the soapy water directly on the plants that are severly affected and then try catching the little pests early in the mornings.

Thank you all so much for your input - I certainly appreciate it!

Happy gardening to all,
Diana

Sorry to hear about your JB problem ollierose. I had the same problems with the JB's and three years ago bought bag a bug. It did no good and probably called them all to my yard, as my infestation was crazy! I pitched the bag and resorted to hand picking, which at the time seemed like trying to bail water out of the lake! there were so many! They are especially attracted to my roses which have been ruined in past years, and my ornamental plum. As well as the daisies. I have also worked on my lawn trying to make it healthy like kimmsr says and it has really helped. I don't know if the JB's are late this year or the roses were early, but I got through the whole first blooming with no JB's in sight. In fact, I just caught my first one three days ago and have picked off about a dozen. I'm still hoping they are not just late, but fewer! keeping my fingers crossed. Has anyone else found the JB's to be late this year or could I really be winning the battle?

I still use the old fashioned companion planting of 4 o'clocks in and around the plants that attract the japanese beetles.

The leaves of the 4 o'clock are poisonous to the JP, yet they are not smart enough to stay away from them, they actually prefer the leaves of the 4 o'clock and will readily chew on the and proceed to die.

It seems that once enough of the JP have tasted the 4 o'clock leaves and die, the message is sent to the remaining JP that this is not a good place to stay and they leave your gardens.

It has never failed for me, never failed for my grandmother in 50 years of growing them and those that I know personally that have used the 4 o'clocks have praised how it works and have been doing it since.

I start my 4 oclocks from seed every year, put some seedlings directly in the garden beds and others in pots to move around as needed.

My roses have barely a munch on them and the malva's and other JP loving plants have barely a hole on them. The leaves of the 4 o'clocks get chewed some and I find tons of dead JP on the ground underneath them in the pots. The 4 oclocks just sprout more leaves, keep growing and growing and their blooms are as delightful to look at and their scent through the beds is as delightful as seeing the dead JP around and nothing damaged by them

Fran

Thank you for posting about the 4 o'clocks. I had not heard of this, if you are finding dead JB's around them, there must be something to it! Today I went out to hand pick the JB's like I have been doing every morning, only getting a few. Well! today is a different story. JB's everywhere, I managed to get dozens, but I saw many escape! Apparently, they were just not here yet. I will be planting 4 o'clocks around my roses and other areas next year, probably too late this year to do any good.
Cathy

Thanks Littleone,

I have only seen maybe half a dozen beetles this year and this is the first year I planted about 8 four o'clock plants, so there must be something to this, hmmm. Many years ago I bought bag a bug and had so many jb's in my yard that I never used it again.
Cathy four o'clock seed sprout very easily. Try some, it might not be too late.

Barbara

The product called Garlic Barrier spray is supposed to leave a strong garlic scent (to a bug's or animal's nose but not ours!) that will foul up the lure of the insect pheromones and send them away. A novel approach! Rather than luring them in with a pheromone-scented bag, we send them packing with essence of garlic! Has anyone tried this product and how successful was it in deterring Japanese Beetles and other unwelcome insects? Supposedly it does not leave a scent or taste to human senses.

I have lots of zinnias in the backyard and have a "bag a bug" in the front. Every day the bag is totally full and there are very few JB's on my zinnias (a total of 5-6 bugs each day after checking at about 30 zinnia plants). Seems to work in my opinion. Kind of scary seeing a bag of them all in one day (1000 bugs!)