Could you post a picture with a close view of them?
Olga

In my zone, the worst of the Japanese Beetle infestation usually lasts about 30 days. They seem to appear in irregular cycles . . . For the last two years, we've had very few JBs, other years they've invaded my garden in numbers that make one's head spin. Here's a link that provides some good info . . .

Here is a link that might be useful: What Can I Do About JBs?

JBs season length depends on severity of infestation. The more JBs you have, the longerv they last. It is a bell curve. In my area heavy infestation last for 7-9 weeks, depending on year. Heavy wave usually starts here in second half of June and lasts until 4th week of August. After and before this period you will have some JBs but nothing comparable to this 2 month infestation period. You can still see few even in October.
I asked you to post a picture, because I think it is important to verify that these are Jap.Bs. You said you never saw them before, so it is better if somebody with experience verify it.This is how they look.
{{gwi:228689}}

Olga

OOOHH!!! I hade never ever seen something like that!! That's incredible!!
I often have read on this forum people talking about JB. But how did they come to the US? Why/what did the "invasion" start? And is it true they cannot be exterminated? (birds do not eat them?)

They first appeared in New Jersey, I believe in the 1930's. It is believed they came in on some imported nursery stock. The USDA has tried to import the beetle's predators (it is not a common beetle in Japan), but the predators have never established themselves very well in the USA. No, the birds don't eat them, or at least they don't eat anywhere near enough of them. The immature beetles (grubs) live underground eating the roots of grasses.

I have not heard that Japanese Beetle is anywhere in Europe. daisyincrete, can you post some pictures of what you're seeing? If you are correct your information may be of some interest to more than just the rose enthusiasts who post on this forum.

Evidently they got into an eastern US port in about 1917 or so in a shipment of iris. They have fanned out west, north and south; nothing has been able to stop the spread.

Imidacloprid kills bees, saw it with my own eyes, because it has residual action even after moderate rainfall. I won't use it again. If it gets as bad as that one photo, I might use it and cut the bloom off after spraying. That is sickening. I had some swarm but not quite that bad.

So if I'm going to cut the blooms off anyway, I'm cutting all my buds during that time, will try to cover with nylon net, a shame, but I can't deal with it and almost developed an obsession trying to pick them all off.

You are right. They attack some and tend to leave others alone but I have other plants in my yard they like, cherry, white paper birch, afraid to try to grow grapes or raspberries.

They especially are drawn to yellow ones or any that have any shade of yellow in brighter sunshine.

There is an ongoing experiment at the U of Michigan whereby they have infected some with a virus that spreads among the adults. Infected beetles were given to home gardeners to test the effectiveness. If it works, it will be a long time before it will be any help to the rest of us.

Our main hope is that a better method can be found. You can be sure when they finally hit California, and they will, something will be done.

A lot of people use traps effectively. anntn6b is an expert about that, puts them around the perimeter of her property. I tried them but no good place to put them, and they just attract hundreds more in, will try to avoid that this year but may have to.

If a community gets together and applies Milky Spore uniformly, that has helped, also Grub X applied a certain time in July to kill the larvae. The best that might do is avoid brown spots in your grasss; they will come in from neighbors and parks who don't think they have a problem.

I am sorry for you.

There are many other beetles that have a resemblance to Japanese beetles. I am skeptical that daisyincrete is contending with Japanese beetles. I expect it's another beetle in the same family (the Scarab beetles). It's an enormous family with thousands of species, many of which are pests.

I believe I've seen a thread recently on the forum that chickens love Japanese beetles and will completely rid a garden of them. If they do make it to California some time in the future, I would dry to bring in chickens or guinea hens to see if that solves the probem.

Ingrid

No, chickens help only a little. It is just too many JBs. Chickens usually pick them up from the ground, but before this you have to collect them from plants and give to chickens. At least that is what I saw in my friends garden. They can't make a dent if the JBs pressure is high.
This is the main problem, nothing really helps. Some methods help to reduce the numbers, but not eliminate the problem. I tried probably everything available. Last year was not so bad in many eastern states. Probably dry summer of 2007 helped. 2004, 2005 and 2006 were awful summers. I collected them in gallons every day. Hope this summer will be not so bad again. By good summer I mean thousands of JBs, not millions :)
Olga

One year, I think 2006, I put traps up and had 10X as many beetles as before. I had to spray, they were not only eating my roses, but my crepe myrtle and cheery trees were being denuded. I actually enjoyed spraying them and seeing them fall to the ground. We had piles of them. I haven't had many since. I don't know if it's because of the drought or if I killed off so many, they couldn't breed and lay eggs in the lawn. But it's been heaven without them.

Thank-you all for your responses. I will take a photograph when I go to the garden later to-day.
Because the house is not yet built, we are renting in a nearby village.
I am pretty sure they are Japanese Beetles. They look very like the photograph Olga has posted. (Thank-you Olga)
My specimens have slightly darker wing carapaces perhaps.
Otherwise they are the same, down to the white tufts of hair around the base of the body.

After sending this post yesterday, I went back to the garden and found they were also attacking my perennial cosmos!

If the rose is open, they go straight to the centre, and eat the pollen and stamens. then work out from there.
If the rose is still in bud. they bore through the rose to the centre.
Babis in the garden shop, knew exactly what they were, when I explained what they were doing.
Thank goodness he speaks good English! I couldn't manage explaining that in my limited Greek.
Daisy

I had to spray, they were not only eating my roses, but my crepe myrtle and cheery trees were being denuded

buford, What did you spray with? We've had another damp spring which bodes ill for another bad season. Roses are one thing but if they attack my new cherry trees, I want to spray with something that makes them fall off like that. I am willing to forego my roses, but if they start ruining other plants, that's enough.

Imidacloprid sprayed directly on them (low concentration) some fly away, you know you've gotten them, but you don't know if they will die. I won't use that again, but I think there are other products that work.

daisyincrete, I will be very interested to see the pictures. This may be the first report of Japanese beetles being present in Europe (except for one island of the Azores).

I keep hoping that what you saw was just some cetonia
From crete to italy it's not so far. JBs would destroy my happy garden.

Here is a link that might be useful: {{gwi:275491}}

We sprayed them with Sevin. This was before I was trying to be organic, but honestly, the swarms were so bad, I had to do something.

I also had a small spray bottle of Imidacloprid and I spot used that it. As you said, they die eventually, but not that fast. With the Sevin, they drop almost immediately. I'm sure it killed everything else that happened to be on my roses at that time as well, even though I tried hard to spray the JBs, not the plant.

buford, thanks a lot. I've put up with enough without using some pesticides. Sometimes compomises are necessary. If it was just my small yard, it might not be so bad, but so little is being done about them in my locale, they are going to get out of control from people not fighting them. Some people don't even know they are here yet because they don't grow roses. I did see two homes not far from me with beetle traps. One house less than 2 blocks from me had one hanging right by the mass of roses in their front yard, don't know how often they emptied it. I walked by there after the beetles were gone, and saw no damage to the roses there. BUT all I remember of those roses, they are pink, think Carefree Beauty. Yellow and orange ones are THE worst at attracting them. My favorites, of course.

I didn't see it myself, but someone told me that in the park on the mulberry trees down the by creek along a lengthy bike path, they were so bad, they were hanging from the trees in chains. I don't know what the city will do about those, if anything. The only thing I know being done was traps in the city park rose garden. Some garden centers don't seem to get too bothered by them. I figure it's partly due to all that asphalt surrounding them because there is no place left to lay eggs, but as they get worse, the beetles will find it all if it's outside. One mailman last year went to work, came home that evening to a completely defoliated elm tree he had just planted.

I will also try to do something about the grubs, but as before, with so few people fighting them, it will do little good. It takes community awareness, effort and dedicated cooperation in the worst heat of the year with high humidity which makes it even more difficult to make any significant inroads toward reducing their numbers.

I think you're ok with your imidacloprid if you cut the bloom off after you spray it because of its residual effects, small price to pay for saving a few bees.

At the point I sprayed, I had no rose blooms left and my crepe myrtles hadn't bloomed yet. I also sprayed my neighbors cherry trees because they were on vacation. It was horrible. I felt responsible because I put up the traps.I have also put milky spore on my lawn, maybe that's helping. Roses will bloom again, but when the JBs swarm a tree, they can kill it. I don't like to spray, but I think it's necessary to take out as many as these guys as possible before they can breed and lay eggs. Last two years, I've been able to use the pick and drown or stomp method. I also sp'ed a yellow rose that was their favorite (not because of that, I suspected it had RRD) so maybe that's another factor. Who knows?

but when the JBs swarm a tree, they can kill it.

Yes, they got into my birch tree clump, no way can I spray that high, but there are bare twigs way up, and I blame the beetles last year for some of it. So that does worry me. If worse comes to worse, I can put netting over my two cherry trees, but as they get larger, that won't be very feasible.

That was nice of you to spray your neighbor's tree(s). Some people wouldn't take it kindly but I'd appreciate it since you know what you are doing.

I did some searching, and to really zap them with Sevin, some people had to make a stronger solution. If the recommended 1-1/2 ounces/gal doesn't work (some say it doesn't), I will go 2, then if that doesn't work, go 3, then quit. I read you have to spray every 3 or 4 days.

I sure don't like to spray either, but even without the beetles, my roses just don't look good except for but a few. In time I'll cull the bad ones, but I'm not going to do it until I know what will work better.

I think it's Evelyn that has brown on the buds this year. I don't know what you spray for that. She was fairly pretty last year. Some the leaves are eaten or scabby or something else wrong. The ones that look the cleanest are Charlotte, Summer Dream, Awakening, Hettie, Wisley, Dark Lady, Pat Austin, CPM's aren't too bad. Even my once bloomers that I won't spray the leaves don't look nice already, but they're tough and it shouldn't hurt the plant(s).

It's OT for beetles, but one side in front my roses are doing the worst, did feed them, but the way the water flows off the sidewalk and flows into one area, 3 roses are just languishing. Are there any class of roses where I'd have several to choose from that can tolerate more damp soil? Dry doesn't seem to bother them so much. I've got a nice crop of monarda in the dampest spot. Was new last year and didn't mildew, might this year.

Sevin works, but if you use it you must remember that Sevin does nothing to spider mites except kill off their predators. Thus, if you also have a spider mite problem you probably should look for another insecticide for the JB's.

I wouldn't use Sevin regularly, just once or twice on the JBs. I don't use any insecticide regularly.

aliska, brown buds could be thrips. They are little worm like insects that you can see inside the blooms. I had them this year, not as bad as the past two, but a few of my roses get affected badly by them. You can spray for them, but it's difficult to get rid of them or prevent them. I try to wait it out.

For the roses in damp soil, I'd try mounding them up a bit so they aren't sitting in water. That might help.

For the roses that are in

I am serving a landscaping internship at a local golf course, and they are gearing up even now to hammer the JB's when they get here. I guess last year their linden trees were hit very hard. They sprayed something, and I know it worked because as I was weeding under them I was crawling around in a mulch of beetle carcasses. *shudder*

Chances are whatever they use is only available commercially, but I would be happy to share info as the summer goes on. I don't plan to spray in my own garden unless it gets out of control. I don't have the time for hours of hand-picking. Last year I hand-picked in combination with covering their favorites with tulle netting like another poster here does. (Sorry, can't remember name right offhand!)

Well! Perhaps I need glasses. Now that I see them on a photograph, I can see they are not the same.
However the damage they do is devastating.
Sorry the pictures are a bit blurry. It was windy.
Can anybody identify them?
Daisy

{{gwi:275494}}

{{gwi:275495}}

Is that green or black? Common rose beetle of southern Europe is Cetonia aurata.

Crete apparently has many species edemic to the island, it may be something not found anywhere but there.

Here is a link that might be useful: Cetonia aurata

buford, thanks, I'll bet it is thrips and will either cut open a bud (lots now) or check when it opens. They are on Enfant de France (don't think last year), Geoff Hamilton, Rosemoor (don't like that rose), and possibly Miss Alice, my namesake, don't like her yet as to blooms either, flat and washed out peach. One Enfant opened and was a nice bloom in spite of it. It's getting dark, will check more tomorrow. Looks like Evelyn is going to be nice. Dark Lady is gorgeous, guy stepped on a cane and lost the whole thing with lots of buds on it.

There's not much there to mound soil around they're so short and stunted (Rosemoor and Miss Alice - they're closest to the french drain). The one on the other side of it does great. I'll try to mound. I didn't plant these, they are grafted and were supposed to bury the graft at least 2" down. We've had tons of rain which is not helping.

I'll get some Sevin but doubt I'll want to mess with it much.

That post about the golf course was interesting, am wondering what they plan to use. I think most lindens might not get too tall, unlike my birch trees.

It's definitely a scarab beetle of some sort (as is Japanese Beetle), but it's definitely not Japanese Beetle. I don't know which Scarab it is, unfortunately. It's not one I'm familiar with, and there are thousands of species (although they don't all eat roses by any means). The scarab beetle family ("Scarabaeidae") is one of the biggest of the beetle families, with over thirty thousand species worldwide.

(As a group they feed on a wide variety of foods, although most feed on plants in some manner or other.)