In some places (my yard) they tend to show up and then leave after about a month. I don't have a huge Japanese Beetle problem. This year the few that are here are only on a few plants so I'm not doing much to control them. If you can keep up the knocking them down it will help to diminish their numbers. When they feed on a plant their bodies give off odors that attract more beetles as does the injured plant. So the more dilligent you are the fewer beetles you will have. Some years, in some places they stay all summer long. Other years you barely notice them.

Pick them off and drop them in a soapy water solution, stomping them only releases their pheremones and attracts more of them. I know it feels good to stomp them but.......

I tried to find support that squashing the JB releases pheromones that attracts more JBs but couldn't find it. But over the past couple of days I've become more of a believer. This is my first year to have JBs and I'm amazed at how many there are. When they first got here a week or so ago, they were on my coneflowers, boneset, beauty berry, just about everything. But they were densest on one particular Rose of Sharon. Over the holiday, I cut back everything that had been damaged except the oak leaf hydrangea and the rose of sharon. They've nearly decimated the Rose of Sharon but now I'm not finding them anywhere else, except the rose of sharon and occasionally on the oak leaf hydrangea. And they aren't on all the rose of sharons--just the one they started on that is so badly eaten up (which will be cut down and dug up this coming weekend). Definitely some kind of communication going on through that plant.

There is supposed to be something that you can spread over your yard so their eggs laid in your yard are killed and you should have less of a problem next year. This is what the Nursery Woman told my mother that is have quite a bit of trouble with them on her roses. Hope this helps if you would like the name of it I will get it from my mom. Good luck! Eliz33

They'll be drowned by the end of this rain spell. Don't worry about it. Never seen jap beetles with life jackets.

Milky Spore (a BT product). Sprinkle it in a four foot grid. The first year also use BT spray - a.k.a. "Neem" - right on the JP's and foliage. The next year the Milky Spore will have taken care of the larvae that lives in the soil and will have slowed the population considerably. Gift your neighbors with some too. Takes a while, but well worth the expense. Another immediate course of action is Guinea fowl. These little beasties consume tons of JP's but they are ugly as sin when adults - adorable as babies. Living in a subdivision and having them is tricky but maybe y ou could rent them out?

I finally saw some JBs without having to look this afternoon -- doin' the WILD THING on the leaves of one of my strawberry plants... A few buzzed off as I plucked, by I managed to get half of the six in soapy water, where the currently reside... and now the pitcher of soapy water awaits further inspections :)

Good luck with your own "alien invasions!"
Jeff

We have an onslaught every year. Milky Spore will not do any good unless everyone in your neighborhood applies it, I'm told.

I just keep spraying with Sevin and it keeps them under control, but nothing is perfect. I have a lot to protect, so it does a fairly good job if you are vigilant. The very first sighting of a JB, we first spray our Japanese Maple who can be turned to fine lace by them in no time. Then, I add Sevin to the concoction I used every two weeks on my roses.

I have found that I have had to spray for JBs about every week on certain plants that they are attacking. Climbing hydrangea and New Dawn climbing rose are two cases in point. Even Knock Out roses are not immuned to these buggers.

Traps are worthless b/c they actually attract more beetles unless the wind pattern is exactly right.

Good luck.

Reeldoc, they didn't drown, they have 10 lives unfortunately. I thought of the little suckers while we were having torrential rains but no, they live and are stuffing their fat little guts at my house!!! I hate them so. What's really gross is when like 10 of them get on one rose bud. JB orgy.

Carla

I'd never had JB's to speak of until this year. What happened?? They're eating my canna blooms fast & furious! I've been spraying with Sevin and I think they are down to a 'low roar'. I just don't understand that while I have lived here for over 12 years that this is the first year of JB infestation. Did I dodge the bullet in years past and it's payback time?? YUCK!!!!
Evelyn

Like efine, this is the first in 12 years that I've ever seen more than one or two. Here they seem to really go for dahlias and roses the most. I go through the gardens 2 or 3 times/day and inspect each plant and flower. Pick 'em up between index finger & thumb and squish. More fun when they are plucked up as a pair because there goes the next generation from that pair. I'm not using the sevin because I have too many bees and hummers around here. Don't want to use anything that might hurt either one of them. The finger method even becomes rather pleasurable after the first few times.

Terribuck - I think you are taking the wrong approach. By removing the one plant they flock to you are setting the stage for them to move over to the next plant. In my yard they are mostly eating up this one banana tree so I am leaving it there to keep them concentrated in that one spot - in fact I may plant more of that type just to keep them off the other plants. In my yard their numbers are already dropping off. When they are gone I will trim up the damaged plants which will recover and look fine in a month or so.

i unintentionally killed a bunch of jap beetles last year. i sliced up an orange and placed the slices in a ceramic dish (with 1-inch-high sides) and placed the dish next to a buddleia so the butterflies could have an extra snack. (this dish had no holes in the bottom.) well, the next night it rained and i went to pour the water out of the dish. to my surprise there were oodles of dead jap beetles (but no butterflies or bees). apparently, they were attracted by the fruit but were too stupid to leave when it started raining and thus drowned. i'll think i'll try that again this year!

patskywriter

I think the numbers are starting to drop off here -- my Double Delight rose is growing some new shoots on top of the chewed ones (that was their favorite plant of all), and some of my Rugosa alba blooms are whole. They really liked the blooms on my pickerelweed too, but no problem there as pickerelweed usually blooms all summer.

I'm a brand new gardener this year. I made lasagna beds on top of the subsoil that our home builder left us. There really WAS no lawn to speak of, so I don't see how putting down the Milky Way stuff to kill grubs would get me very far ahead. For those of you with lots of unhappy experience with these $$##**^% bugs: do most of the plants that they've snacked upon live throught this? Looking bedraggled, but alive? I can live with plants that look raggedy-a$$ed for a while - heck, I look raggedy-a$$ed sometimes my ownself! But will my new plant friends live through this?

When I finally got frustrated by the sheer volumes last week, I cut off the blooms of roses and cone flowers they were devouring. I didn't cut back the rose of sharon assuming that it was serving as primary bait. But....since planting the rose of sharon I've learned that it is invasive and since it also appears to be a JB attractor, I don't think cutting it down (after the JBs depart) is a bad decision. I didn't have any JBs until this year--the first year I've had a rose of sharon. I can't be sure there is a cause and effect relationship but I'm not going to take the chance since the "cause" is also an invasive. I don't plan to dig out the roses or the oak leaf hydrangea, the JBs other favorite orgy sites in my yard. I will be laying down milky spore (milky way! :)) this fall. I'll do anything to prevent this invasion from occurring again.

I purchased a systemic product - I think it is called Bayer Tree and Shrub. They had it at Lowes right in front of the check out in the garden center (it's in a blue bottle). Just mix it with some water in a bucket and pour it around the base of trees and shrubs that you have problems with. Last year those darn JBs totally defoliated a tree in my yard in a matter of days, and it was too late to act by the time I realized it was happening. I bought the systemic stuff to be prepared, and even set a reminder in my Outlook calendar to be sure to put the stuff out around the beginning of May. Of course, I never did it. I thought (mistakenly) that I was going to be fortunate enough to be bypassed by them this year. But no such luck. I think they were just late this year. At the first sign, I put the systemic product out, and although I still see some JBs near the tree and on some of my flowering plants near it, the leaves are still hanging in there, and mostly looking okay. The product is supposed to provide a year's worth of protection against a variety of insect pests. I don't know what the negative affects might be, but seems to me that something systemic will only harm those insects that are trying to eat my plants.

However, my Lord Baltimore Hibiscus in the back looks horrible. I tried spraying Liquid Sevin, but didn't really do much good. I'm just waiting until the JBs are gone then I'll cut it back. Does anyone know if it will put out new growth this year if I cut it back? Haven't seen one single bloom because of those nasty bugs.

~Angie

Well I am here to tell you....I've been in this area 4 years.All of a sudden the last week I have been invaded!!!! They have devoured several small trees, all the flowers from my cannas, and now they are working on some fruit trees by my veggie garden... I am afraid the corn is next!!!!!!!!We bought this house 2years ago and there are rose of sharons next to my back door they were never bothered. I remember gpa having a tin can with gasoline he would brush everyone he saw into it.... there are soo many....

I really believe in the Milky Spore solution but its kind of expensive especially if you have a few acres(3) like I do. Is there a way to use the traps and Milky Spore in conjunction to speed the eradication of the beetles?

The thing to remember about milky spore is that it takes time to work. As some have noted, it doesn't work as well if others are doing nothing. I am using milky spore and the number of beetles in my yard have been going down when others are going up. I didn't lose a single plant last year. My neighbor put some traps out last year and had to empty them every day. I only did my garden beds with it the first year. The next year I did near the azealas and part of the yard. I am going to do another part of the yard and the roses this year. I have an acre of land so it may take me a little bit of time. That is why I have been doing it a little bit at a time. I think the combo of the traps, spraying with sevin (only a little) and the milky spore is a winning combo. At least until they get under control. Then I would cut out the sevin all together. Remember that sevin will kill all bugs. Good and bad.

I did take some time to catch a few and toss them in the pond. I think that it was more for my enjoyment then anything else.

Good luck all with this pest.