Japanese beetle defense for green beans

It is very early for this, of course, but I'm trying to plan how to defend my pole beans from the Japanese beetles. Last year, they largely converted the leaves to lace, and were present for many weeks. No matter what I did, they were always there feeding on my green bean leaves in force. Now the moles have been digging up the soil near the garden like crazy all winter, so I presume that all those beetles laid eggs in the grass which have now grown into grubs that will emerge to feast on my green beans again. I'm sure that the moles have eaten some, but many will emerge hungry this summer.

Picking all the beetles off by hand is not a good option. I can only do that once a day, at best, and those buggers are there all day in numbers feasting while I'm at work. Has anyone ever tried barriers to protect pole beans? If so, how do the bees pollinate the flowers? Are there any other suggestions?

We really love fresh green beans, and I hope to have more this year than we had last year.

I like companion planting for insect repelling. Catnip is good for Japanese beetles, and you don't have to actually grow it in the same square, just sprinkle the leaves around on the soil. Chives will grow in the same square as your beans and repel them, so will garlic.

You can make kelp "tea" (health food stores carry kelp powder and leaves) to spray on the leaves once a week, too. Or, you could grow a pot of larkspur and set it right next to the plants. The beetles are attracted to the larkspur but it is poisonous to them.

I'm going to have to try a few of those. They are infesting my roses every year and I am tired of going out there with my jar of soapy water several times a day to keep a check on their damage. They discovered my peas and beans as well last year and I'd rather keep my harvest to myself than share with them.

Thank you.

It's expensive, but highly worth it. It's available as a powder or as a pellet. Runs $40-$45, kills beetle grubs in the ground, and lasts for years. Safe, organic, etc.

Tom

Tom - what pellets and powder are you talking about? Bt?

1airdoc wrote:Tom - what pellets and powder are you talking about? Bt?

http://www.stgl.us/gstore/productcart/pc/viewCategories.asp?idCategory=44

While the above site shows only the powder, I have a 20lb bag in pellet form purchased from Agway

http://www.agway.com/catalog/home_and_garden/pest_control/grub_control/10202105_milky_spore_20lb.html

I have used Milky Spore for forty years or so. Works good. It used to be hard to get, but not now.

Tom

Mamachibi wrote:I like companion planting for insect repelling. Catnip is good for Japanese beetles, and you don't have to actually grow it in the same square, just sprinkle the leaves around on the soil. Chives will grow in the same square as your beans and repel them, so will garlic.

You can make kelp "tea" (health food stores carry kelp powder and leaves) to spray on the leaves once a week, too. Or, you could grow a pot of larkspur and set it right next to the plants. The beetles are attracted to the larkspur but it is poisonous to them.

These are great idea!

I wondered why catnip was recommended so much as a plant. Insect defense!

Thanks for the heads up.

Tom, I'll definitely look into milky spore. Since the beetles fly in from a large area (>300yd), how large an area do you need to treat in order to be effective? We have several acres, and I don't think I could afford to treat it all.

1airdoc wrote:Tom, I'll definitely look into milky spore. Since the beetles fly in from a large area (>300yd), how large an area do you need to treat in order to be effective? We have several acres, and I don't think I could afford to treat it all.

I think the pellets are the most practical application. 20lbs of pellets treats 7000 sq ft. The bag says to do 6 applications over two years.

In order to spread the cost out, I would do first a perimeter of the garden, as far out as you can afford. Also in the immediate vicinity of any plants you want to protect. The following year, expand the circle. This stuff really works - you will see a marked decrease if applied now, while the grubs are still in the ground.

As an aside, I have two bug zappers, one on each side of the pool house. Last year we had very few bug problems, in the pool area or in the garden except in the evening. We don't use insecticides at all, as we have a large bird population providing daily concerts (cardinals, mostly). I suspect that our zappers got the really nasty bugs, or at least kept them from getting out of hand.

The alternative to the pellets is to use the powder. I've used this in the past (it was all we could get) and it's difficult to spread on the ground evenly. But if you have roses, you will not mind spending a small fortune on the stuff.

I'll be spreading my milky spore in pellet form sometime this week, hopefully.

Tom

Someone mentioned last year using the beetle traps, I believe she got them at Lowes, I'll have to check the archives. I need to get those this year because my beans got laced last year too. The good thing about the traps is if you have chickens, they like Japanese beetles like I like cheesecake - yum. The down side I've heard to using the traps is that it attracts the Japanese beetles to your property, but as long as the traps catch them, that's okay with me. I tried some home-made traps last year using a milk jug and I forget what liquid, but it didn't work.

NHGardener -

This is the post I remember:
https://squarefoot.forumotion.com/t8126p15-happiness-is-hunting-for-japanese-beetles

Was very interested because we live in an older neighborhood with lots of Rose of Sharon all over and they flock to it...

I have read about the Japanese beetle traps from several sources. They are effective in attracting and trapping huge numbers of the beetles, but they only capture about 75% of the ones they attract. If the traps are not far away from your garden (or other tasty landscaping plants), then they say you end up attracting even more beetles then the plants attract on their own, and your beetle problem can be worse than it would have been without the traps. I've even read the tongue-in-cheek suggestion that you should give the traps away as gifts to all your neighbors if you want to keep the beetles out of your yard!

I may get a few traps this year and place them at least 50 yd or more away from my garden (and crepe myrtles), just to see what happens. I think that the suggestion I read in another thread to put the traps 10 yards away is not far enough.

I'm going today to get some of the pelletized milky spore to try. I know that is a partial long term management solution, but it is better to start now and then have ongoing benefits for several years.

I've also read about using Bt for this problem and would love to use it in conjuction with the milky spore, but it requires a specific Bt variety (Bt japonicum) that I haven't been able to locate. That is also a long-term residual agent that is safe for people and animals.

I've heard pro and con about the traps. But I'm going to try them out this summer and see what happens. Maybe I'll place them far from the garden, or maybe near, not sure. I'll report the results. Anything has to be better than last year when they tore apart my bean leaves.

Last year was my first time planting LATE beans. I planted on Aug 15th. I normally have problems with those beetles and also a bean beetle in the spring. No problems. Beautiful beans. It worked because the beetles "had run their course" before my beans sprouted at the middle of August.

Great idea! You're only located 100 miles from me (in Clarksville, TN), so that timing would probably work for me, too. Did you plant on 8/15, or did they bloom on 8/15?

If you use catnip as a repellent, won't they also be an attractor for cats to come and roll in your squares???

I suppose they could be. The plastic fork trick works for that, as does having a territorial cat that isn't affected by catnip (about 15% of cats aren't.)

I planted a late garden on Aug 15th. I had particularly good luck with bush beans, and broccoli/cauliflower (they were under row covers).

Started my own germ warfare: got the milky spore (pellets) spread before we had a nice rain, so hopefully those spores are doing their job infecting the grubs.

I know that will take some time (a couple of years) to be greatly effective, however, so I'm still wondering about how to handle the beetles that will come this year.

Gotta admit that I can't imagine why any companion plants will work to keep the JB's away from pole beans which are many feet above the ground and far away from the "companions." Those beetles don't have any problem bypassing their less favorite treats in order to chomp down on the beans (or roses, or crepe myrtles, or....). I have put tulle over much of my garden this year, but I don't know if that will work on the trellis.

Tom or Airdoc, in the same way, how does milky spore keep them off a pole bean?

I do love the point that MS takes care of the grubs in the dirt!

AvaDGardner wrote:Tom or Airdoc, in the same way, how does milky spore keep them off a pole bean?

I do love the point that MS takes care of the grubs in the dirt!

Milky spore kills Japanese Beetles in the larva stage. After they have emerged and become flying bugs, its too late. But the MS lasts for years, and will eventually kill all those suckers before they become adult bugs.

Tom

Are these JB grubs the same thing referred to as chinch bugs on the packaging of lawn insecticides?

givvmistamps wrote:Are these JB grubs the same thing referred to as chinch bugs on the packaging of lawn insecticides?

Don't know. I don't use lawn insecticides. The nice thing about Milky Spore is that is all organic. It only affects grubs in the ground.


"Milky Spore is a bacterium, Bacillus popillae, which is lethal primarily for Japanese beetle grubs. Once applied, it can remain in the soil for many years. In warm climates, good control of the Japanese beetle can occur in one to three years; in cooler climates, three to five years.
The life cycle of the Japanese beetle includes the immature beetle, called a grub. It stays in the soil of your yard and garden, feeding on the roots of your grass and other vegetation. Once Milky Spore is applied, the grubs ingest it as a normal part of their feeding. The more spores are in the area, the greater the chance of infection. Each infected grub dies within approximately 3 weeks and releases new spores.
Milky Spore is not affected by freezing or other adverse environmental conditions. Milky Spore is not generally affected by most fertilizers, pesticides, herbicides and other lawn chemicals.
Milky Spore Powder is considered harmless to food crops. It may be used in gardens, around pools and near wells. Milky Spore is not known to affect pets, beneficial insects, fish, bees, birds, other animals, plants, or man......."
http://www.arbico-organics.com/product/milky-spore-powder


Tom

givvmistamps wrote:Are these JB grubs the same thing referred to as chinch bugs on the packaging of lawn insecticides?

Michelle- I don't think so.

Here is a chinch bug and here is a Japanese beetle.

Last year I saw several Japanese beetles and a milkweed bug (apparently a type of chinch bug) on my beans so I do think they can coexist in the same area at least in my neck of the woods.

UnderTheBlackWalnut wrote:

givvmistamps wrote:Are these JB grubs the same thing referred to as chinch bugs on the packaging of lawn insecticides?

Michelle- I don't think so.

Here is a chinch bug and here is a Japanese beetle.

Last year I saw several Japanese beetles and a milkweed bug (apparently a type of chinch bug) on my beans so I do think they can coexist in the same area at least in my neck of the woods.

Thanks; I recognize the chinch bug as something my son thinks is pretty...but not sure I've seen Japanese beetles around here.