Return to the New to Gardening Forum | Post a Follow-Up

Japanese Beetle Invasion

Posted by souppeggy z8GA (My Page) on
Thu, Jun 30, 05 at 7:22

Again this year I have noticed a bug devouring leaves on plants in my garden. I noticed it last year for the first time but didn't know what it was until I did some investigation on this website. I will consider almost anything other than picking them off as there are so many. Please help me.

Follow-Up Postings:

RE: Japanese Beetle Invasion

  • Posted by tapla z5b-6a MI (My Page) on
    Thu, Jun 30, 05 at 7:28

Picking them off is a temporary solution as more immigrants arrive on the next flight. Neem oil is safe, a powerful anti-feedant, & works well to steer the unwanted visitors to other, untreated plants.


RE: Japanese Beetle Invasion

I'm no bug expert, but I know that before Japanese beetles become adults, they are grubs just lying in the ground (those fat, grayish white C-shaped worms that I always smoosh with my trowel). Has anyone ever treated grubs (gotten rid of them) before they grow to adulthood and take over the garden as adult Jap. beetles and does this work? A pound-of-prevention kind of thing.

RE: Japanese Beetle Invasion

I think Mrs Emily is talking about 'milky spore' which is rather expensive but is apparently the only thing available that controls the grubs (and thus the beetles). While the initial $ outlay will probably make you say ouch, the spores stay effective up to ten years -- I would say, in our area of torrential downpours, you could reasonably expect about about 8 years before needing to re-apply. You won't see much difference the first year, but there will be a considerable reduction the second year, and few beetles the third year. It's best if you can get your neighbors to do their soil as well!

souppeggy, I don't think anyone likes picking off Jbeetles, but wear disposable gloves and carry a small bucket of soapy water [to dump the bods into] to make the chore bearable - and drowned beetles cannot lay eggs to bug you later. Actually, if you've got access to a couple pre-teens, they seem to like the chore - pay off with pizza, and you'll probably have the best beetle-hunters in the neighborhood. BTW, even bad infestations don't really take all that long to clear, thinking about it is far worse than actually doing it.

RE: Japanese Beetle Invasion

Merit is an effective all season grub control. I use liquied sevin in a spray bottle and make my rounds every evening when they are less active. I'd say I kill over 200 a day and every day there are just as many more. At first I thought the sevin wasn't working until I noticed I was accumulating large piles of dead beetles under my roses, crepe myrtles, etc. I use care to only spray the crepe myrtles in the late evening after the bees have knocked off for the day, as I don't want to kill them, just the JB's.

RE: Japanese Beetle Invasion

Link is to some really good info from Ohio State on Jbeetles! Including controls.

Dieter - haven't you used milky spore? Or are you in the area where it doesn't work well? 200 [or about 25 minutes of hand-picking] is about where I figure it's time to re-apply the ms - I used to use 100 as a guideline, but I now have 4 out of 6 adjoining neighbors who don't care about jbs and won't apply ms.

Here is a link that might be useful: japanese beetles info

RE: Japanese Beetle Invasion

Here's some info about JB's from Mike McGrath, former editor of Organic Gardening Magazine:

"Come fall, beetle battlers should plant some (or more) forsythia, peonies, firethorn and tulip poplars to attract the spring tiphia wasp (tiphia vernalis). Deliberately released in the U.S. a few years after the dreaded beetle was accidently introduced (in 1916), the wasp was recently rediscovered alive and well here on the East Coast (from New York down to North Carolina). It's a great beetle enemy - the female wasp goes down into the soil and lays her eggs right on the grubs, so more beetle-battling wasps emerge instead of those armored rose-eating pests! The wasps can kill 85% of the grubs in a lawn. That's better than nasty chemical insecticides achieve!"

Important info: These wasps closely resemble another feared pest - winged black carpenter ants! Luckily, the wasps' attraction to the above-named plants (and not to the wood of your house) should help you ID the good from the bad, so the good can survive to go after the ugly."

And, I might add, milky spore does work! I found only two JB's so far this year in my garden.

RE: Japanese Beetle Invasion


Last year was my first real experience with Japanese Beetles. Fortunately I was forewarned by a neighbor. I've done hours of research on the subject but as for actual experience, I don't have much.

Well, let me rephrase that, I don't have much experience as to what actually works on them. I do, however and unfortunately, have plenty of experiene with the actual bug itself. Boy do we have them around here!

My understanding of Milky Spore is that it will kill grubs in the soil but will have no effect on adult JB flying in from miles around to feast on your plants. Apparently JB can migrate up to 5 miles from place of origin but typically don't fly more than a mile or 2 away.

I hand pick them. I don't really have to touch them. A bowl of soapy water in one hand and knock them off with the other. They fly downwards most times so they tend to fall right into my waiting bowl of water. While I'd rather not have to deal with these little boogers at all, I do get a somewhat twisted satisfaction of watching them fall into the water to drown....never to bother my roses again!

I have poured the drowned bodies on the ground and I'm sad to say they are still there in a pile,so nope, birds don't come along and eat up the dead ones.

I am trying a neem product. I just started using it. I know I was supposed to start using it as soon as I saw a bug but I was so trying not to use anything other than handpicking.

I was fine with this method until the little b@**@*ds decided to pick on my nicest rose bush in my yard. Now I'm at war. I won't use "nuclear weapons" such as sevin on them but garlic and neem oil are definitly on the ready.

I also plan on planting garlic and rue around my roses. Not sure if this plan will work but since I like both of those plants, it certainly can't hurt. I'll enjoy eating the garlic and enjoy looking at the rue:)

I guess I'm on my way to IPM. Integrated Pest Management. I'll use any and all ideas. But I can not/will not resort to using sevin, malathion, etc.

Good luck and know you are not alone.


RE: Japanese Beetle Invasion

I have tulip poplar, forsythia and peonies up the wazoo but the day the Japanese beetles arrive my garden gets out of control. They don't go for my roses - the grape vine is the favorite target, and the ugly corkscrew bush next to the vines.
I pick and I pick and I pick. I squash them with my bare hands. I tried some recommended stuff once - diazinon? Are things like sevin supposed to kill the bugs on target, deter them or coat the leaves and kill them through ingestion? The stuff I used didn't seem to have too much affect on them.
I have a trap for the first time this year - I'm getting 200+ a day and far fewer on my plants. I have a large property so I'm going to place another trap at the other end. The weird thing is the trap doesn't kill them, they are all in there squirming around. It's gross. I have to dump the bag into my detergent bucket.
With acres of lawn I can't afford MS. I hope eventually I can make a dent in the population but these bugs seem bent on procreation!

RE: Japanese Beetle Invasion

  • Posted by vstech z7 Charlotte (My Page) on
    Tue, Jul 12, 05 at 15:47

from what I have read on posts and such, MS is not only good for approx 10 years, it spreads very quickly across HUGE areas, including your neighbors yards. so a large yard would be perfect for the MS. and that wasp sounds like it would take care of the rest@!

RE: Japanese Beetle Invasion

Hi! I wonder if anybody knows where I can find a list of which plants JB don't like in Michigan? I don't want to use chemicals if I don't have to and am hoping to plant some more JB-repellant plants next year. Thanks!

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the New to Gardening Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here