MissyWeitzel I tried using geraniums as a trap crop for the Japanese beetles last year but it didn't work.
My understanding is that’s it’s best to avoid anything that attracts them, even as a “trap”.
I’ve also heard recommendations to instead convince your further-away neighbors to plant the trap crops. 
Emily, I am also in zone 5 and have used green lacewings successfully for at least 5 years. I will have to try the pirate bugs as well, but have been delighted with the results of the green lacewings!
Each year I buy 18K lady bugs online and distribute them over my beds. There are online services to buy all sorts of beneficial insects. I was plagued with spider mites and aphids before I did this.
My father grew completely organic and would order lady bugs a couple times a year. He would walk up and down the rows and place one lady bug on each of the plants. I remember he said it was important to already have an insect infestation so the lady bugs would have something to eat. Otherwise, they would fly away soom after they were released. They did a great job of controlling aphids for him.
Lots of good reminders here about not planting things that will become invasive. In the mild climates of western Oregon and we really can't count on winter kill of anything but tropicals. As for Aphids, I find that the lady bugs arrive soon after the aphids do and the problem is short lived. I'm aiming for that goal of encouraging butterflies and birds and I guess if I have them I have to be providing some of the food they like too. I guess I just need to know if there is something I should NOT be patient with if I see it in my garden. What plant or bug should I rip out of get rid of any way possible if I see it show up? SO FAR, at least, we do not have Japanese Beetles here. For which I am most grateful. A warming changing climate means that where the bugs invade and thrive will be changing too.
calico20hill SO FAR, at least, we do not have Japanese Beetles here. For which I am most grateful
I had no idea there were parts of the US that were safe from the JB scourge! Lucky you!
I find that bagging blooms excludes JBs pretty well, and I don’t mind the extra work.
My most difficult pest to deal with is the tarnished plant bug, which can still manage to slip into the organza bags. From what I read, they have no known predator either. Let me know if anybody here has a good organic solution for them - we have quite a lot for most of our blooming season unfortunately.
Juliarugula Yes, I don't think they have reached CA at all. I expect the ag industry here will do what they can to keep it that way.
The beetles are only a few steps away from us now...its been great while it lasted.
I guess they monitor for them constantly here and eradicate any introductions. fingers crossed
If anyone wants to permanently get rid of Japanese beetles... I highly recommend putting this down in the spring / fall called Milky Spore. Then the following year in spring. You get a 15 year barrier. It has cut my JB population down by 95% as well as voles no longer dig in my yard after the grubs because there are none. And rarely in the dahlia area.
They also have a spread broadcast ones like lawn fertilizer but its not as effective
Thanks for that share, NCDahlia! I discovered, quite by accident, that alfalfa pellets work for Japanese Beetles. I had a large order of Bearded Iris to plant and I use alfalfa pellets when planting. I had a plastic tub refilled with the pellets when a surprise torrential rain shower hit, so I grabbed up what I could and ran. I was slow to get back out there, but when I did I discovered Japanese Beetles floating all over the top of that tub!
NCDahlia I’ve always hesitated to spend the money on milky spore because I live in a suburbanish neighborhood where all the lots are no more than a half acre. Seems like even if I take care of the grubs growing in my yard, there will be plenty from the neighbors.
Do you live further from other yards, or do you still feel it helps?
Juliarugula I live like a stones throw from others like 100 yards. I am in an HOA. I will sometimes get them from the neighbors but it's not many. They can not lay the eggs because the spores kill all the grubs thus no new japanese beetles can hatch in the spring. I still get some but its nothing like I had 3 years ago and this is with still planting on the other side of my property runner green beans which the beetles love to decimate the leaves of beans.
I view it as good stuff. I try to do more organic and not a ton of pesticides. Also I am already spending a few 100 $ on new dahlias each year (lol) so I think having the other stuff helps cut down on the problem.
A few of us are all getting together and buying a bunch of green lacewings this year. They're native to AK so I wouldn't be introducing something that's not here. We have to overnight them - which is spendy to AK - but split 4 ways it's not too bad. I'm also rather intrigued by the whole BRIX idea. I know some growers who swear by it. I figure I'd give it a shot. I don't, knock on wood, usually have too many issues with pests (aside from slugs) which is good because it's hard to spray even the pollinator friendly treatments at the height of summer. They say to do it when the critters aren't active - like at night - but when it's light all the time it's hard to find a time they're not active.
AKWindWatcher I can't wait to talk to you about it this summer to see if we notice any difference in pest pressure. I'm looking forward to trying a lot of new things this season. First thing I want to try is making my own compost tea. My husband bought me a fancy backpack sprayer last season and I feel like I could be in Ghostbusters when I use it, so I love any reason to spray my plants! 
Other than beneficial nematodes, releasing beneficials to combat pests is new to me in the garden. I’d always assumed releasing flying insects in an outdoor garden space would be rather futile.
That being said, I was beginning to discover what I believed to be thrips, although I’ve never identified them before. Yesterday I released 500 adult Orius insidiosus and it seems like overnight my pest trouble disappeared! I’m shocked and feeling relieved at how quickly they went to work!
Minute Pirate bugs are the best! Although they occasionally give me a nip here and there, they are so good at getting rid of the bad guys, that I don't mind.
