There is no environmentally sound way to prevent damage to the flowers. I just shake the beetles off into a pan of soapy water and wait for them to go away.

Once the beetles are in full force i have too many roses to hand pick, some are too tall to reach or I wind up stepping on something. Nothing i've tried as a preventative works. I spray them with an insecticide. They are about the only reason i use it. i've tried traps, and BT. They don't seem to work.

The only "trap" that seems to work is to grow a tall light-colored fragrant rose as a decoy , they seem to like them best. i prefer the dark colors, anyway.

I just endure the scourge and don't bother any more, ruined whole summers picking and drowning. I won't spray because of our loss of bees, tried Sevin on things that weren't blooming, and rain washed it all away. Please don't use anything with imidacloprid (it works but at a price to any bees or wasps) as the active ingredient.

It's better to kill them than repel them, but my neighbor got some food grade diatomaceous earth at Lowe's, wore gloves and a mask even though it's pretty safe, dampens the plants, and sprinkles that on his hibiscus. They don't like the gritty, and you can buy a dispenser somewhere, I'd have to look up who told me.

I might pick off buds, but they still go for leaves and certain other plants. Some have covered all their roses with that nylon netting which works.

My yard is too small to site traps effectively, and they just draw more in, had hundreds one year.

I just pretend they aren't out there, if I walk by one, I can't resist squashing it with my fingers though.

I'm always open to some new, safe discovery that will eradicate them completely. Milky Spore is not an option for me, and Grub-Ex one year might have helped but they'll just come in from somewhere else.

I have a friend who has them really bad at the moment and she says she's been spritzing them with a Dawn dish soap and water solution. She said they just rolled over, dropped and died! Could it be that easy?

We've been using Milky Spore on our lawn and I have seen a greatly reduced number of them since we started. I only saw maybe a dozen in the whole garden last year.

We had several years of bad Japanese beetle attacks, each year worse than the one before. The year that the chimney swifts showed up, nesting in our chimney of course :), was the year the beetles all but disappeared. We removed he nest after a few years. (DH had intended to do it sooner but for several years running we heard little bird chirps coming from the fireplace just before he could get around to it). Now the chimney swifts are gone and we have some beetles but not very many.

I also once saw a cardinal eat a Japanese beetle. I do not spray

Cath

Beetle populations vary according to last year's weather. Drouth in late summer and early fall kills the small larvae because they are unable to move around in hard soil. Here we had years of severe drouth which ended last summer. The population in my neighborhood (where people don't irrigate turf) dropped down to negligible and is still down, but will rebuild in time. This year I haven't seen a single JB yet, just a few of the paler asiatic beetles. In bad JB years we have them by now, though July is the peak month.

Well, they poked their nasty bodies out of hiding a couple of days ago here in central Illinois and are about their business of eating ravenously everything in sight.

After reading an earlier post of someone's success of using Dawn, I mixed up a spray bottle using 'Dawn w/Oxy' and went out and sprayed 'South Africa', who was being devoured alive. To be honest, I didn't expect much to happen. Almost immediately, the devils acted like they had been sprayed with a high-powered insecticide and started staggering about, curled up their ugly beetle toes, and died. Am I ever stoked!!! I need to go on a beetle-killing, Dawn rampage now, but with a one-gallon sprayer. That little spray bottle isn't going to do it with over 300 roses.

Quite possibly, I think it is the Oxy that is doing the job. I just know I'm glad it is working so I don't have to beetle pick.

terryjean:

How much of it do you use? I've only seen about 6 jb but it's early yet so I want to be prepared.

Dennisb1, I just added about 1/2" or so in the bottom of an empty floor cleaner squirt bottle and filled the rest up with water. I'm going outside now to see if they're back on the scene of my earlier carnage; will report back soon.

Well, the Dawn spray is NOT a deterrent, but kills when it comes in contact with the beetles. However, the bad news is that it definitely crinkles up all the rose blossoms like old tissue paper...but I guess the JBs would eat 'em all anyway. I hate JBs.

Japanese Beetles are the # 1 enviromental disaster in the state of Maine.. Followed closely now by the asian beetle that bores into trees.

Luckily I have both =P .. What a nightmare.

Nothing will work other than spraying them with a massive insecticide.

Im a organic gardner, that doesnt spray anthing for mostly anything.. nor do I use chemical fertilizers.. I use a mixture of horse manure and compost for the most part every year to top dress my gardens. Im not a huge fan of doing this.. but, if you do not you are just promoting thier population even more.. I figure If I can kill 50,000 in a year, thats 50,000 less to populate my immediate area. I think one year when I lived in my old home, I probably killed over a million as I had a massive rasberry patch, like 300 feet long. I no longer grow rasberries as its pointless to try without a spray program.

Im not going to condemn you for spraying them. I guess this is up to the individual, can it kill bees? yes, it sure can, but the other flip side is allowing the population to grow in your immiediate area, that is also having a massive negative impact to the enviroment. Not sure there is a win for anyone here. Its a loss to everyone.

However, Ive broken down and sprayed the JBs in the past. You cant hand pick them when there are maybe 10,000 in your yard at once. The traps are worthless, they capture some, and bring more in to eat around your yard.

The nemotodes that work to maintain the grub population has show ineffective with temps below 0 to -10 where they will not grow in population enough.

So again northerners are stuck.. with no clear answer on what to do to control them.

Silverkelt

When I went out the looked at the bush I sprayed with Dawn, it was clear that the soap spray was very harsh on the leaves, so I'm going to discontinue the use of the spray. It also fried the blossoms.

I even saw the JBs chowing down on the neighboring coneflowers...new introductions that just bloomed this year that I was really looking forward to enjoying.

And you're right, Silverkelt, if we spray, we impact the bees, the good insects, butterflies, etc., but to do nothing is to let the JB population go unchecked. It's frustrating.

You can't really check the population of JBs, since they fly around the neighborhood looking for roses and sexual partners.

Thanks for the update on the soap spray terryjean. You answered the question I had, was going to pick up some Dawn w/oxy whatever that is.

For some odd reason, haven't seen any yet and it's so nice to enjoy my roses while I can even though I neglected them.

They're worst on hot sunny days and in the sun but when they're swarming, you can find them anywhere.

The person in Maine, I thought that's where they let loose that parasitic fly a couple years back, actually think it's waspish. They lay eggs in the female which, when hatched, feed on her inside until she's dead. That's the kind of long-term program I'd like to see so long as there aren't unintended consequences.

I used to have a bad JB problem. One year I tried the traps and the problem became a disaster. Not only were my roses infested with thousands of JBs, but my cherry trees, crepe myrtles and my neighbors cherry trees were being decimated by the horde. The traps attracted more JBs but didn't really help to capture them. I had no choice. On morning I went out and sprayed with Sevin. I sprayed the bugs, not the plants. There weren't many bees out because there were no flowers left and the cherry and crepe myrtle trees hadn't bloomed yet. I had piles of dead JBs on the ground all over. It was satisfying to see them squirm and die.

Since that summer, I have had less and less JBs. I have not seen one JB this year (knock on wood). I've also put down milky spore years ago, I'm not sure if that's done anything.

You can't just leave the JBs to breed more JBs. You have to take action. If you are careful when and what you spray, you can limit the damage to bees and other good insects. My yard is now filled with bees, wasps and other insects. JBs are not natural to our country, they don't have any right to survive. Just MHO.

Terry, why did you add the OXY? That's a bleach. No, not a chlorine bleach but a bleach none the less. I have used dish soap solutions on my roses for years and never had them burn as a result. I think it was the OXY and not the soap that caused the burn on your roses. I checked with my friend, Mary, and she had no burn what so ever on her roses using just the dish soap and water solution. She used an old Windex spray bottle with about a half inch of Dawn in the bottom and then filled it with water. She is continuing to soap all her roses and although it has not eradicated all the beetles, it has helped her save some of her blooms and her newly planted cherry tree's leaves that the beetles seemed to love!

If you do like using the soap, once it's done it's job of killing the JB's you could rinse the plant clean with plain water.

Saw the first ones today in my Crown Princess Margareta blooms. Squashed them. I'll try the dish soap and see what happens. It was wet all day yesterday; they don't like that, so they must have been in the area at least a week. Hope I don't have to put up with them into September.

So far I have only seen a few in Central NY. I know there are more because rose leaves are being chomped. My yard has lots of birds of many different species, from the dove I keep seeing walking around the vegetable plantings to the small songbirds on the bird feeder, to the robin nesting over my door. I am using another door for the duration of nesting season, I even saw gold finches this afternoon, and some more birds I can't identify. So far, I think the feathered visitors are dining on JB, also the garter snakes in the compost and the frog hiding in shrubery might be eating some. Where I am, the mosquitoes are a far worse pest.

Seil, the Dawn dish soap had the OXY already in it; it's a fairly new Dawn and it's what I have on-hand. I need to hit the grocery store and grab some plain old Dawn and try it without the OXY additive, I suppose.

We're having so much rain here that I can't even make it out to spray. I've noticed those darn cucumber beetles are also making an appearance in great numbers also....along with an insane amount of mosquitoes and gnats. Must be all the monumental rain we've had all summer.

Per the USDA and my own experience, ingesting geraniums (Pelargonium zonale) paralyzes the beetles and sometimes causes their guts to die. If they don't die, the paralysis makes them vulnerable to predators, who clean up. (A gardener on the rampage can kill the beetles with terrific abandon and total success for 24 hours after paralysis starts).

Interplanting geraniums with roses has done the trick for me.

I have the pelargoniums growing everywhere amongst my rose beds and they haven't deterred the darn JBs at all...glad it works for you, though.

In my experience, geraniums (pelargonium) made a few beetles sick, but did not reduce the assault on the roses in any noticeable way.

Thanks, I will have to experiment with the soap. Just saw my first one today (chicago area). Typically they are fourth of july through labor day. What is the optimum time frame for applying the milky spore (zone 5)? In spring or fall?

The ext ofc told me milky spore doesn't work well in our zone. Well, I suppose it could if it survives our winters. I suppose there are always differences of opinion.

I'd read that 4 o'clocks kill the beetles if they eat them. So I got a bunch of yellow seeds, haven't planted them yet because I'm not sure I want the big tubers they make in the ground and don't really have a clue if they work.

aliska, chances are the agent's office isn't just giving an opinion, but referring to research done in your area. Besides, most of the beetles in your yard probably weren't bred in your yard.

Hi aliska, my grandmother planted 4 o'clocks in her gardens and showed me JBs dying after eating them. I've never forgotten the sight.

Reading since then confirmed that 4 o'clocks are poisonous to the beetles. They are also poisonous to humans, so be very careful if you plant them. I've never had the courage to include poisonous plants in my garden, so I have no experience of my own. But I will always remember my grandmother's garden and those JBs dropping dead.

michaelg, anita22, all, exactly, most are coming from the park where they can't keep the populations under control.

The 4 o'clocks don't bother me as poisonous plants because I grew a couple varieties of Foxgloves, but I suppose I'd have to worry about some kid putting stuff in their mouth (some will). We were fascinated with 4 o'clocks when I was a kid, waited until they set seed, they're interesting black, and picked them out of plants; nobody would have dreamed of eating any. I don't think our parents knew they were poisonous.

My father, however, grew some fine castor plants. He made sure we knew those were poisonous. I don't like them anyway as plants.

Just got back from the store with the Dawn original. We'll see how that soap spray works. It's tricky digging 4 or 5 out of a bloom which shatters and gets a bunch of petals in my soapy water.

If it seems to work well (I don't know how they can fly after getting a lot of soap film on them), I can make up a batch in my sprayer, and hit areas I'm not bothering with now. They've got too many lucious roses to feast on now, maybe it's good not to snap buds off like I did one year, let them ruin blooms, at least I know where they're most likely to be congregating. They are obscene what else they do. It gives me great pleasure to catch them in the act and ruin it for them.

Found this informative USDA publication on the web, fyi. It was last revised in 2004 however. It mentions two parasites that are natural enemies of the Japanese Beetle--a wasp, Tiphia vernalis (attacks grubs); and a fly, Istocheta aldrichi (attacks adults). There are also lists of plants that are either resistant or not to beetle feeding (thereby making your yard more or less inviting!).

Here is a link that might be useful: Managing the Japanese Beetle: A Homeowner's Handbook

I heard the fly typical symptoms showing up in Maine, nothing here in the midwest. Saved a photo on my other computer and the eggs were white spots near where the head connects to the body, then when they hatch, they eat the female beetle from the inside.

I got a bottle of original Dawn and probably made it too thick because the only spray bottle available is opaque and I couldn't see if I had two inches.

Well, it certainly seems to work, got tons of them this evening when they're lethargic, would have taken me a lot longer to pick them plus more would have gotten away. Some were definitely dead when I checked back. Some dropped off after a couple of good squirts. And they're in full active stage now, up to six on a bloom, some on leaves; they've totally decimated all the roses that were blooming.

Now if it just doesn't damage around the plants and rose leaves I sprayed, won't know for a few days; I'm hoping it will dry overnight before sun hits tomorrow then eventually rain wash it away. I'm not too concerned about bees (they were done for the day) and residual but wouldn't want to squirt one.

Thanks terryjean for such a simple solution.

I am a broken record on this - comes up every year, and every year my answer is FREE RANGE CHICKENS! Yep, they cleaned them out of my yard completely. Last year due to raccoon predation I kept the two old girls and the six babies in their run all summer, and I am curious to see if I'll have any this year - but as of July 7 - none!

I've killed Japanese Beetles immediately with a direct spray of Castile soap, mixed with 1/3 "Rose Pharm" and another product that contains organic peppermint oil. So far the soap mix seems to discourage them from congregating on my clematis vine in large numbers. Japanese beetles form groups and if you keep killing the "first few beetles", the larger group doesn't congregate. They are eating crab trees 50 feet away that are too large to spray but not bothering Knockout roses or Carefree Spirit rose much. They love my clematis!!

I make Castile soap mixture buy grating a half bar of pure Castile soap into 1/2 or 1 gal of water and either let it dissolve slowly or use an electric beater, [you can make it thick and dilute it as needed so it will spray ok]. I added "Rose Pharm" because it's too expensive to use alone and contains peppermint oil and also added a shot of "Biocontrol Network" Pure-Castile Soap mixture that has peppermint oil and rosemary extract in it. The peppermint oil is supposed to repel insects. I added the two last products to the Castile soap mixture because I already had them and they're fairly expensive to use on tons of beetles. It' safer to spray early or late in the day before the temps reach the 90s but I had to spray the beetles in direct sun yesterday, so far clematis leaves haven't wilted and mature rose leaves aren't bothered by the soap mix. So far its a test, I might put netting over the clematis next year.

Aliska, we do have the parasitic wasp here in Maine that attacks the adults. It was not released by Maine, but some other state in the NE and migrated here. You can tell when a bettle has had the egg laid on it (of which the larva later bores into the beetle's body and kills it) by a little white dot on its thorax. We had the parastic wasp show up nearly ten years ago and were very excited about the prospects. It seemed like every other beetle had a little white dot early in the season. But unfortunately they really haven't done much to the population. I have heard that the wasp only feeds on the beetles early in JB season for about two weeks, and after that the "wasp season" is over for them and billions of JBs go around uninfected.

Regardless of whether they are poisonous to beetles, I don't see how four o'clocks or geraniums would work. I have grown both and actually never saw a JB on either. Both are not in their list of favorites foods.

The jury is still out on milky spore and nematodes due to coldness factor. I used milky spore several years ago and it didn't seem to do anything. It doesn't matter anyways what you treat your lawn with if your neighbors do nothing--the grubs will just come from there to feed on your roses.

I have been spot-spraying the beetles themselves with Bayer Rose & Flower insect killer. It is the only pesticide I use. Spraying entire bushes with the pesticide doesn't work. It doesn't seem to have much of an affect, is certainly not a deterrant, and besides, as new flowers unfurl every day they are untreated unless you spray constantly. So I use the spray as a weapon vs. hand-picking, which I did futilely for many years. I have to go out and hunt beetles/squirt them at least once a day, but it really keeps their numbers down in my garden because there aren't any big buildups of beetles attracting more beetles. I have to be vigilant about it every day so the numbers don't get up there--nothing attracts JBs more than other JBs. If you can keep the numbers down, you will have less beetles flying into your yard. I have been doing this for several years, still have the same small bottle of Bayer concentrate, and our lawn is pretty much grub-free as very few of the beetles that make it into my yard lay eggs because I kill them all. However, I can literally see them fly over the hedge from the neighbor's lawn into my roses.

Here in Italy I have a similar problem with the Oxythyrea funesta beetle. I was wondering about putting up netting to form a physical barrier.For example, Veilchen says (he or she?)can literally see them fly over the neighbour's hedge. Now, would it be possible to erect some tall posts on your side of the hedge and stretch netting along it? How high off the ground can beetles fly? If their preferred height of flight is, say, 6feet above ground level,would a net screen that is ,say, 7 feet high be any help? What do you all think? Because I've sort of identified from which direction O.funesta is entering my garden,and was wondering if constructing a high screen on that side might be of some help. regards, bart

I've seen Japanese beetles in the tops of plum trees that were over 12 feet tall. Hope this helps.

Cath

I observed many times JB completely destroying all leaves on linden trees, cherry trees, plums, etc. Some of these trees were much taller than than 30'. I don't think fence will help :)
olga

They get worse every year, have been swarming but I noticed they pick certain spots on certain plants and blooms. I see by all the holes that I've missed a bunch, didn't go out for awhile.

I tried the 2 inches of Dawn in a spray bottle, shook to mix it, and it worked. BUT I oversprayed a lot of places and damaged several plants, both roses and perennials. So no more of that but will try it on weeds, almost works like RU.

So I had part of a bottle left of Bayer Advanced Rose and Garden Insect killer. I had four but swore I wouldn't use them any more on roses. But my cat got fleas bad and I couldn't afford much then and it has the same active ingredient in Advantage you put on the cat, just less strength. I sprayed the carpet and bad places with the Bayer and Adv on the cat, $10 a pop, vet asst told me it take four apps for the cat to mop up the fleas, she was right. Just have to get away and not let the cat near it til it dries, then it's ok although some spots I had to do 3 times. Darn cat knew where the fleas were and wouldn't walk through there and made sure to jump up on something high lol.

The active ingredient is imidacloprid which kills bees. So I put on latex gloves, pruners in one hand and spray bottle in the other. Zaps them. If I spray a flower or get some on a nearby flower, I prune it right off and deadhead a little at the same time. I don't have to worry about the dormant roses they swarm on or rose leaves because bees usually only stop at blooms. I go out between 5 and 6, there are a few bees, but I haven't accidentally killed any.

I like it because I can cover more territory faster, clip other stuff at the same time, aim further than I can reach, far fewer get away than they do from the soapy water drowning, and it's working better for me even though I know there are tons more up in my birch trees I can't reach.

If you're still doing the soapy water, 3 swarms together won't work, but if they are swarmed in a rose blossom, I cup my hand over the blossom which keeps them from flying up, get the water underneath and tease them out of the bloom, most just drop right into the soapy water but I get petals in it and pick them out.

terryjean, I don't know where you are in IL, but they must really be bad in Peoria County. I read in my Illinois Farm Bureau Farm News that the crops were showing signs of heat stress and no rain and that crop dusting planes were spraying for Japanese Beetles and also fungicide. I think with the wet spring, many farmers got their crops in late, the corn was at the silk stage, and too many beetles will get an ear with no corn. I was told the soybeans could take it. I shudder to think what they are spraying, probably something commercial grade, but it will kill all insects along with the beetles.

Here they're doing all these hideous transgenic experiments with animals, saw a picture of a beagle puppy; it's white nose and light body parts glow red in the dark, for real, photo was on ABC news site, makes me sick. But if they could do something with the beetles like that where they wouldn't cross into the other insect population, I'd be all for terminating them.

Sorry it's so long, spend a lot of time learning about different things. Too hot and humid this summer to enjoy much out there, then drought. Finally got some badly needed rain and now with the Bix weekend and RAGBRAI, we are having our 3rd flood of the Mississippi this year.

Yesterday, I was reading an older gardening magazine ... 1989 ... and one of the items mentioned to deter japanese beetles was to plant WHITE geraniums to ward off JBs.

I don't have JBs in my garden ... I battle with rose curculios ... but I have often found that the advice in old garden books and magazines does work, but as chemical solutions to insect problems arrived, these old ways fell out of use.

I am just sharing something I found.

Smiles,
Lyn

I agree with the poster that the traps attract more beetles. My worst years were when I used the traps. My best year is NOW: only 4 beetles on my Knockout rose, and NONE on my 10 English roses (mulched with horse manure and watered abundantly).

The worst years were when I used Bayer chemical fertilizer and insect repellent on my roses, ending with hundreds of beetles on roses. Last year I didn't use any chemical fertilizer, and zero beetle. This year, no chemical fertilizer, only horse manure, and very little beetles.

I wonder if anyone have similar experience? Horse manure also helps with blackspot on roses, there are a few articles on using composted manure tea for blackspot, and tree bark contributing to blackspots on roses.

I also start a compost pile in my garden: melons rinds, veges scraps, and banana peels. I think the Beetles have a feast on my compost pile and ignore my roses.