I don't know if repellents can have any effect, since the beetles will attack the flowers and these unfold fresh petals every day. It would be interesting to spray half the white roses, half the yellows, etc. with a fair mixture of colors and fragrant/not fragrant (factors in JB preference). Then see if there is enough difference to justify handling this unpleasant and somewhat hazardous spray material. Do at least wear safety goggles; I'm sure it is a significant eye hazard as well as skin irritant.

Yeah, that's why they tell you not to wipe your eyes after cutting hot peppers. Capsaicin is what makes hot peppers hot. I'm just thinking that it will just be seasoning, like Tabasco.

well, I spray with a vengeance against thrips but sloppy impatient me just wears a thin vinyl glove and will often skip even that! but have never had any problems...though plenty times I catch a backwind of pepper that makes me cough slightly, doofus me! I just have my good 'ole eyeglasses, no goggles whatsoever..I just always wash my hands afterwards...But absentminded me never thought about washing out my eyeglasses right afterwards, LOL! so hmmm, no more sloppy ways I suppose...

I suspect that JBs are far more nasty (they look like they've got some sizeable jaws and very thick impenetrable armor so I bet the hot pepper spray won't work as well as an "irritant", but then I wouldn't know because I don't have JBs yet...I read on a few threads in which people will tap JPs into a bucket of soapy water which does! kill them. Karl uses tulle netting to protect the blossoms.... Maybe you can do this until you have cleansed out the majority of the JPs. Canola oil or PAM will also clog up their digestive system so maybe you can spray that on the leaves --that way you can hit them with the DOUBLE Whammy! canola to mess them up internally and the soapy water drowning! Then when they are under control you can release your blossoms from the tulle. Let me know if you decide to try any of these possibilities... I would love to learn an effective strategy especially if this unwelcome bug were to intrude on my roses.

No.

(I have tried it.)

I was told Japanese Beetles prefer their blossoms seasoned.

I don't think capsaicin (which is what makes hot peppers "hot") has any effect at all on JB's.

What I'm seeing in my South NJ garden..

Beetles are horrible.
Take my purple cone flowers, the heads & undersides are filled with JB's. They also love yellow primrose & one variety of my Loosestrife - the common purple - they don't appear to go on the pinker one.

Roses - my rugosa Polar Ice is loaded - they are eating the foliage as there are no blooms. My Roseraie de l'Haÿ' not so much. They are also on Leda eating foliage. Ballerina is so-so with JB's.

My Gene Boerner is blooming, they are not touching it.

They are on the wild blueberries, maple & oak trees. They aren't on the Laurels so much.

As far as sprays - the best I've used out of Seven, Orthene, Ortho Max (red bottle) and Ortho rose pride - the Ortho max & Ortho rose pride are the best. Rose pride kills them the fastest.

It will stop deer and rabbits but not JBs. The best thing for JBs I think is milky spore. You put it on your lawn and it kills the grubs in the sod. It's organic and does not kill other bugs or birds. Of course, JBs can come in from other yards so it's not 100%. and it can take a year or two to be effective. I did it about 5 years ago and am noticing many less beetles the past few years than I had in the beginning.

And yes, be careful on getting pepper spray on your hands and rubbing onto face/eyes. Wear gloves and eye protection. Wash your hands well and then wash your face afterwards.

It will make no difference what you spray, dust, or apply to your roses to prevent JBs, because it won't deter them in the least. As far as I know, they have no natural predators except Milky Spore, and an application of that in your garden or on your and the neighbors property could be very expensive. Of course, one application replicates itself in the ground and lasts for over ten years, but then...

There have predators in the Orient, and some of those have been introduced here in the USA, but none of them have provided meaningful control over here. Unfortunately the predators (other insects that only go after JB, establishing that fact is a prerequisite to introducing such insects into the environment here) don't seem to prosper in the environment over here the way JB does.

rroselvr, this is off-topic, but felt it worth mentioning anyway: Purple Loosestrife is a very aggressive invasive non-native that is wreaking havoc on waterways all around the country. Why it is even permitted to be sold is beyond me.

Would you consider replacing it with another plant, even a loosestrife, that is not so damaging?

Some biological controls have been developed for Purple Loosestrife, but it is not a solution, as such. the solution lies with the growers and buyers.

Here is a link that might be useful: More info on Purple Loosestrife

Why it is even permitted to be sold is beyond me.

If I remember correctly in Massachusetts it no longer is legal for nurseries to sell it.

Greenhaven, I bought them years ago before they stopped selling them. I usually don't keep many of the purple as I like the pinker one better. When we moved, I dug plants, trying to remember what was what, I don't doubt the purple seeded and came with me. I pull the seedlings out and discard. I know it is invasive if I let it be. Right now I have 3 purple, one is going. I actually thought it was pink when I planted it where I did.

Does anyone know if garden snakes eat JB's? This was in my garden yesterday. I saw him eat a white worm from the bee balm - wasn't sure if he ate JB's too. I also have toads. {{gwi:308183}}From Snakes

WAY cool snakes!!!

Good to know you are aware of the loosestrife issue. Is it possible to cut and destroy seedheads rather than risk animamls taking them away? I don't know if their anatomy or bloom habits would allow this.

yorkrose, good to know it's not available at least there, any more! I have seen it offered in catalogs pretty recently. Made me MAD!!!!

I actually do cut the heads off too.
I try to anyway. Same for cleomi here as that can be invasive too.

Not the greatest pic (didn't edit) but this was the JB's today
{{gwi:295015}}From Wildlife - bugs etc