japanese beetles everywhere

I want a japanese garden...not bugs!
I am finding japanese beetles underneath my pots but so far no damage is noticed on my potted trees. But out in the growing field...thats a whole other story. The red oaks, siberian elms, a couple of the native elms are being attacked by jap beetles. The damage in the siberian elm is what i want to say severe. The damage looks like spotty holes all over each leaf.
What i am looking for is advice and or suggestions on how to control or eradicate these pest by getting rid of them....not attracting and then trapping them.

To the best of my knowledge, Japanese beetle damage to trees is not fatal. You might consider it a form of defoliation. They are very difficult to control (best done at the larval stage while they're in the soil in fall or winter), and control on your property is usually overridden by "visitors" from neighboring properties anyway.

From everything I've read/heard, the only truly effective approach is to treat the ground with milky spore. However, unless you own and can treat several acres surrounding your garden, it probably won't be all that effective. In a typical urban/suburban area, you'd need to get the neighbors to treat their properties as well.

On a smaller scale, you might try planting some "sacrificial" plants to lure them away from your trees. For example, I've found they absolutely swarm to porcelain berry vine and tend to leave my nearby bonsai pretty much alone.

Japanese Beetles meet, fall in love, eat your plants, then basically deposit their eggs right at the base of whatever plant was host for their first date. The cycle repeats next spring. I cannot stress how wonderfully effective Milky spore is at controlling, and breaking, the reproductive cycle.

I have a pussy willow that has been a particular favorite of the beetle, even with just a ground treatment underneath and around the tree, the beetles are gone! And have not returned, thats because their life cycle is pretty close to home as it were.

Good stuff.
-Jay

Hmm, that's interesting - but goes against pretty much everything I've read about milky spore (i.e. needing to treat large surrounding area). Then again, maybe most of that is advertising hype? Maybe I'll give it a try.

Did it take a couple of years to work, or was it pretty effective the first season?

coh wrote:Hmm, that's interesting - but goes against pretty much everything I've read about milky spore (i.e. needing to treat large surrounding area). Then again, maybe most of that is advertising hype? Maybe I'll give it a try.

Did it take a couple of years to work, or was it pretty effective the first season?

To be honest Chris I'm very suspect of the "extensive range" of treatment recommended for controlling these bugs that I keep hearing. Just watch them (try to) fly and how clumsy and limited they are. No, these guys are seasonal, repeat feeders with each generation emerging from underneath the host tree of their parents. That has been my experience and my successful spot treatments of certain trees has confirmed it for me.

I have had it work in one season, application in spring and no Beetles on the pussy willow come June. l re-apply every two or 3 years just for the sake of overkill. When I first moved to this property I was overrun with Japanese Beetles now I'm surprised when I actually see one they have become that rare and I guarantee none of my neighbors have treated their property with spore.

Even in a worst case scenario where japanese Beetles from other properties manage to infiltrate your property, if your ground is inoculated with spore, their offspring will not survive to bother you next spring. So its a win-win.
-Jay

Hello everyone,

I to have had much trouble with these beetles over the past few years. I found the best method that I have been using for the last couple years is to hang two beetle lure bags at the opposite ends of my property, this has cut down the beetle down by about 75%, I eliminate the others by filling a wide mouth plastic container with a solution of water and dish soap. Hold the container under the leaves with beetle and tap the leaf with your hand, they fill fall into the solution and drown. I do this once every three days or so.

Hope this helps,
Abe

When I lived in MA, japanese beetles were a summer scourge and nothing really worked to prevent their damage. My FAVORITE method of control was to hand pick the buggers off of my trees/veggie plants and toss them into the webs of the numerous weaver spiders that routinely took up residence in my gardens...very cathartic .

For some reason, I found myself looking for the Like button, Dave. Wish I could implement one on this board ;-)

I love those spiders -- except when they weave their webs across my entryway overnight and i walk through them in the bleary early morning.

Eastern Bonsai wrote:Hello everyone,

I to have had much trouble with these beetles over the past few years. I found the best method that I have been using for the last couple years is to hang two beetle lure bags at the opposite ends of my property, this has cut down the beetle down by about 75%, I eliminate the others by filling a wide mouth plastic container with a solution of water and dish soap. Hold the container under the leaves with beetle and tap the leaf with your hand, they fill fall into the solution and drown. I do this once every three days or so.

Hope this helps,
Abe

Yeah, I'd suggest the same with the beetle traps; they don't eliminate them all, but will take care of a large portion of them.

And again....I'm back!

I knew it was coming, after an inglorious summer last year of running around with containers of detergent/water from bonsai to bonsai. But the little devils got up in the morning before I did and had eaten their fill so I was going to be ready this year!

I researched Milky Spore and discovered that Minnesota is too cold to host the spores. The one bonsai the Japanese beetle seemed to love is my little-leaf linden which I hope to show soon. It has an outstanding trunk taper and I have started removing leaves for reduction. Therefore, I have moved the tree to my patio away from the beetles breeding ground and I bring it into the garage every night.

My question comes after seeing a spot on the news last night about our new pest. The reporter had done his research but of course it was mainly about large trees and how it won't hurt them in the long run. He did suggest covering potted plants with cheese cloth...!! Has anyone on the forum attempted this for bonsai? or perhaps netting?

Thanks for any thoughts....

Norma

I have a young linden (tilia cordata) and have noticed that the beetles have a definite taste for it compared to the other potted trees. However, we've got enough other, large stuff around that they prefer (in particular, they flock to a large porcelain berry vine not too far away) so they've done very little damage. Have never tried covering trees with cloth but it might be worth a try.

Have you ever posted a photo of your linden? Would love to see it.

I used to be overrun and still have them show just in significantly lower numbers.

I put a lawn insecticide down in spring that kills the larval stage of the beetle each spring. And I sprinkle a little powdered insecticide on my trees when I see the first one show up as well. Basically looks like powdered sugar. And you don't have to put much of it on the trees either. Just the littlest bit kills them.

Just a follow-up about my battle with the beetle and efforts to protect my Tilia cordata which some call little-leaf linden or lime. My tree which I've had for 15+ years is, I suppose, not favored by many bonsai growers because of the tree's large leaves. I've read that the new spring leaves are used in salads by some cultures.

Last year the beetles ate every linden leaf, but this year .....none! I moved the tree to my patio under the umbrella until I could purchase netting to cover the canopy where it still waits. The table is near a Virginia creeper vine that provides shade to a work area and the beetles have been feasting on these. They also have worked on the cherry tree and birch. The question is why has the linden gone untouched?
My first reaction was could the umbrella be protecting the linden? or are they completely sated by the vines which cover a large area of redwood fence?

Chris asked for a photo of the tree which is in a 12in.(31cm)x 10in.(25cm) Sara Rayner pot. The tree stands 17in.(43cm) tall and the base of the trunk is 4-5 in.(13cm) wide.



Best regards,
Norma

Three cheers for the vine! Distraction is always an appropriate approach to pest control.

Nice looking tree! The leaves are definitely a little large, but they have such a nice shape...and the opening buds in the spring are a wonderful sight. Is this a species that can tolerate defoliation? On mine I've noticed (so far) there appears to be one growth spurt per season, so maybe not.

Thanks Chris,

The tree had been defoliated in early July but because I've kept it virtually out of the full sun, the leaves are a bit larger and the color lighter.
The trunk is getting a nice aged look but I must admit to using a experimental technique on the trunk bark about ten years ago.
Short vertical cuts with a sharp knife seem to produce more flare. The one problem I've experienced is the need to keep the branches trimmed regularly or get long branch internodes and you can't depend on back budding. Also I haven't done any wiring lately because the tree doesn't respond well.
I'm thinking of tie-downs for some of the lower branches.

I'd love to see your tree! It seems there are few linden's shown in bonsai so I have had few for comparison.

Norma

Norma wrote:
I'd love to see your tree! It seems there are few linden's shown in bonsai so I have had few for comparison.

I wish I had something to show! I've got 2 of them, but both are in the very early stages of "growing out" for trunk size (which is only about an inch at this point). No branch training at all yet, just being allowed to grow. One is in the ground as of last spring, the other is in a pot but probably destined for the ground next year. The one in the ground has produced at least twice as much growth (measured in terms of number of leaves and length of each shoot) so I think that's the best option.

I've had a problem with chlorosis especially with the potted one...by this point in the summer the leaves tend to get rather yellowish (while maintaining greenish veins). It's being grown in a bark-based mix and I alternate fertilizers, most of which have pretty good trace element coverage. Have you had any issues with this on your tree? The one in the ground looks better.

Chris

Smart move, Chris, putting your tree in the ground! I did this with several small ginkgo and am pleased with the way they have shot up.

About the chlorosis, I started seeing this in one of my large Japanese maples. The difference this year is the extreme heat we've been having and the number of times I water in a day. So I ordered Biogold pellets(pricey but worth it) which do not dissolve as rapidly and the large shallow pots are now using some of my flat stones under one side to slightly tip the pot. I still use a liquid fertilizer and a dry sprinkling of 2/1 cottonseed/bone meal at least once a month. Another factor is the hardness of your water supply, mine is city water and very hard so I've been gathering rainwater to at least use with the Miracle-Gro and I don't use fish emulsion anymore after reading about the amount of salts that come with them.

Good luck ... I think we need it, if this unpredictable weather continues or becomes the norm!
Norma

I've got them too. I'll have to try that milky spore stuff.

If you do, try to get your neighbors (all 4 sides) to do it too. Otherwise, you're wasting money.

Gary Swiech wrote:I've got them too. I'll have to try that milky spore stuff.

Try and get it applied the day before a good rainstorm so it gets watered in deeply. It is the only thing that has saved my 16 tree fruit orchard and my grape vines.

The American Elm I spot treated earlier this year still has all its leaves intact and uneaten, which compared to last year at this time, is nearly a miracle..the stuff works..

Good luck
-Jay

Well I doubt very much I'll get my neighbors to do it unless we have a "Let's all get rid of the Japanese beetle party with a grill present".