Japanese beetle control

Hey all!

My bines were hit hard by Japanese beetles last year. I ended up spraying them with insecticide which killed most of the beetles (for a few days) and then I got a spider mite attack since I'd also killed the beneficial insects. This year I'd like to not spray chemicals on the hops if at all possible. What is everyone doing to control Japanese beetles this year?

I put milkey spore down last year, but that won't help for a while, even then it only kills the grubs on my property, the beetles will still fly in. I may get a bait bag to put in the front yard.

The bait bags seem to attract more .

Clonefarmer said:

The bait bags seem to attract more .

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That's sort of why I wanted to put it in the front yard, far away from my hops. I have also thought of giving bags to my neighbors

conpewter said:

That's sort of why I wanted to put it in the front yard, far away from my hops. I have also thought of giving bags to my neighbors

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The neighbor idea sounds good.

I heard the same thing about the bags, although i may try them this year anyway. I have a good deal of open space behind my yard and it wouldn't be that hard to hang a few.

Safer Soap worked well for me. I had to spray repeatedly - every 4-7 days - throughout the worst of the infestation, but they were gone by the time they started to flower and the plants didn't suffer much from the bastards.

The adults are a brilliant metallic green, generally oval in outline, 3/8 inch (8 to 11 mm) long and 1/4 inch (5 to 7 mm) wide. The wing covers are a coppery color and the abdomen has a row of five tufts of white hairs on each side that are diagnostic.

The larvae are typical white grubs that are C-shaped when disturbed. First instar larvae are about 1/16 inch (1.5 mm) long while the mature third instars are about 1-1/4 inch (32 mm) long.

Ryan099 said:

The adults are a brilliant metallic green, generally oval in outline, 3/8 inch (8 to 11 mm) long and 1/4 inch (5 to 7 mm) wide. The wing covers are a coppery color and the abdomen has a row of five tufts of white hairs on each side that are diagnostic.

The larvae are typical white grubs that are C-shaped when disturbed. First instar larvae are about 1/16 inch (1.5 mm) long while the mature third instars are about 1-1/4 inch (32 mm) long.

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Yeah ... any suggestions on controlling their devastation of the hops?

Granpa used a cup of motor oil set near his grapevines...They seem to love to take a dip in it, and never get out..

wow awesome, used or fresh motor oil? I'm going to try it.

svengoat said:

Granpa used a cup of motor oil set near his grapevines...They seem to love to take a dip in it, and never get out..

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That sounds simple enough to work!

Hmmmm japanese beetles....Which oil do Toyota recommend?

Clonefarmer said:

The bait bags seem to attract more .

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That's the point of the bait bag. You place it AWAY from where you don't want them to be and they are all attracted to the bag instead of your plants. My parents had some bushes that were getting ate up so they asked the neighbor to place one in his yard roughly 500 feet from the bushes. Neverhad a problem with beetles again. The bag always filled up by the end of the year though!

SOB said:

That's the point of the bait bag. You place it AWAY from where you don't want them to be and they are all attracted to the bag instead of your plants. My parents had some bushes that were getting ate up so they asked the neighbor to place one in his yard roughly 500 feet from the bushes. Neverhad a problem with beetles again. The bag always filled up by the end of the year though!

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My yard is pretty small and I probably had it too close. 500 feet is like two streets away . The weird part is I had a problem before the bag, it got worse while i had it, than after I got rid of it I haven't had a problem since.

Well...I think 500 feet was an over statement but they do live in the country and things are more open. I would try putting it in the front yard if the hops are in the back or on the opposite side of the house from the hops.

Also, I think the beetle "infestation" varies from year to year. Not sure what effects them but I know some years are usually better than others. On the bad years there's almost nothing my parents can do to completely get rid of them.

Motor oil must smell sweet to them, take a shallow container and place one or two near them.. When the critters get too high scoop out the dead ones and reuse the oil..

Milky spore seems to be the best longterm solution. However, you have to treat your whole lawn with it, it's expensive, a PITA to put down (buy the applicator or make one), and starts to work best after a couple years. If you have neighbors, it helps to get them to treat their lawns as well. We had a terrible J-beetle problem last year for our garden, so I treated my lawn in late summer, as did my neighbors. We'll see how it works this year.

EDIT: Sorry conpewter... I just re-read your post about how you already put down milky spore. I'm an idiot.

Hey no problem, I've already got some useful hints here. I will try the motor oil, if that works then I'll be golden. Otherwise it'll be a bait bag in the front yard I think.

We'll see if the milky spore helps any, I didn't buy any for the neighbors (expensive as you said).

We had a huge problem with Japanese beetles when we moved into our house 3 years ago. The house was empty for a year or two before we bought it, so the beetles were using the backyard bushes for their orgies.

We treated with grub-X last two years, and last year, I don't remember seeing more than a passing beetle. I think it helped that all our neighbors were treating their grubs too. I also used Sevin on the bushes to mass kill the live ones, but I didn't have hops then.

Everything I've read about the bait bags, is that you don't want them near your property. Even in the front yard, the bags will attract way more beetles to your home, than you'll kill with the bag. YMMV

Good luck!

OK so here's another thought I had. What about one of those bug-zapper lights out in the yard, will Japanese beetles attract to those? I could even get the scent stuff from the bait bag and put that in there. I know the bait bags don't always work because they won't trap them all, but a bug zapper gets them even if they get nearby.

conpewter said:

OK so here's another thought I had. What about one of those bug-zapper lights out in the yard, will Japanese beetles attract to those? I could even get the scent stuff from the bait bag and put that in there. I know the bait bags don't always work because they won't trap them all, but a bug zapper gets them even if they get nearby.

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I don't know, but I do know that Jap Beetles are active during the day and much less active at night. I think those bug zapper lights are more effective for nocturnal insects.

I haven't had any issues with the beetles themselves but, we do have the larvae (grubs). For those, I opted to go with benificial nematodes. Supposedly good for 10 years and self regulating according to food source.

I might have to try the motor oil myself as an additional insurance.

SOB said:

The bag always filled up by the end of the year though!

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End of the year???? Man, I put one out in the schoolyard behind my house and I had to empty it about every 3rd day at it's peak.

I put milky spore down last fall, and a year before that some nematodes. The nematodes really helped with other beetles in the garden, but still had problems with the Japanese beetles. Like milky spore, it takes a while for the populations to become effective. I put both down in my yard, one neighbors, and a halo out into the schoolyard. Two other neighbors have a lawn service. Grub control must be done in late summer or fall (around here). By this time of year, the grub control products available to the home user don't work on the more mature grubs.

A bug zapper won't work on them. They "roost" at night, which actually makes it the best time to spray for them. During the day, if you spray, a bunch will take off and not get sprayed. At night however, the little buggers stay put, making them an easy target.

Bug zappers do work for them...if you have one with both a day and night bulb in it. The base of my parent's bug zapper is full of carcasses every summer as proof of that. The problem with bug zappers is that they kill anything attracted to them, both the good and bad bugs.

Maybe try some companion plantings:
Plants That Repel Pests - The Green House

Looks like garlic, rue, geraniums, catnip, tansy, larkspur, chives.

I always put marigolds into my vegetable gardens for insect deterrence, should work for hops too.

Daddymem said:

Maybe try some companion plantings:
Plants That Repel Pests - The Green House

Looks like garlic, rue, geraniums, catnip, tansy, larkspur, chives.

I always put marigolds into my vegetable gardens for insect deterrence, should work for hops too.

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I had garlic planted around the hops last year, didn't make a difference at all (garlic gets to what... 12" high? the hops are at 18'). The garlic is tasty though

My Tansy never came up, the geranium that works is not a perennial up here. You have to get Zonal Geraniums, I may still buy some of these and hang them near the hops.

Japanese Beetles are attracted to YELLOW, so any can / container with yellow and a viscous liquid works , motor oil is just another viscous liquid , liquid soap also works.

Paint inside of can yellow and they will try to get in, as they are not qualified pilots they usually crash land each time and the liquid gets and holds them.

Bug bags with bait work the same way , yellow plus scent, small opening and they are stuck

I've never seen a Japanese Beetle here in Oregon.

*knock on wood*

IXVolt said:

I've never seen a Japanese Beetle here in Oregon.

*knock on wood*

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Japanese beetle range

Like pjj2ba, I was emptying the bag at least once a week the year I put one up. It's the same year the buggers were covering some of my trees so much that you could barely see the leaves. I ended up just spraying sevin on everything or I wouldn't have had trees left. Luckily, I live on a lake and everytime the bag filled up I would go shake it out into the lake and the fish a turtles would get a meal. How about using Neem oil? It's supposed to make plants unappetizing to pest insects without hurting the beneficial bugs and is non-toxic so it's safe to use on plants that will be consumed.

I put down $400 worth of milky spore in our yard two years ago. I couldn't tell any difference last year, but maybe it will help this year. I've already given up on the hops, though. Maybe I'll come around to it again later on.

I have a friend who put out dozens of bait bags and collected beetles by the bucketfull every day. They started to smell so bad that he had to dig trenches in his yard to bury them all. Yuck.

I just make up some soapy water. Fill up the pump spray and go to town. They fall off the plant and die rather quickly. Had a horrible infestation a few years ago on the apple and pear trees and that worked well. It doesn't last so you'll have to keep spraying. The farmer planted beans on the rotation this year so I'm sure I'll be making lots of soapy water. Just a thought for ya.

Hit those Beatles up with a good dose of Yoko.



*sigh I do this every year.
https://www.homebrewtalk.com/forum/showpost.php?p=321588&postcount=8

My wife has been looking into organic everything and the one interesting tidbit she through my way was that you can use white vinegar in a spray bottle as an organic insecticide. Also it deters cats in the plant beds so maybe a dual purpose.

Anyone ever tried it ?

I am going to do some looking and post if I find anything.

Lucky Dog Brewing said:

My wife has been looking into organic everything and the one interesting tidbit she through my way was that you can use white vinegar in a spray bottle as an organic insecticide. Also it deters cats in the plant beds so maybe a dual purpose.

Anyone ever tried it ?

I am going to do some looking and post if I find anything.

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Have heard it kills weeds, but I am trying it right now on some of mine. (weeds)

Straight distilled vinegar didn't do crap to my weeds grr. I've heard salt is great if you never want something to grow there again.

JarrodH said:

Have heard it kills weeds, but I am trying it right now on some of mine. (weeds)

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Yes she said that straight should kill weeds, but a diluted solution is meant to keep bugs away. I haven't found where ever she saw this, but I did find that it say putting straight vinegar will repel 4 legged animals rabbits, cats, deer...

i have used onion spray to get rid of pesky bugs ...

juice a onion and put the juice in a spray bottle with water and spray the leaves of your plants.

i have used that for many plants and it seems to work. (might want to keep it off the cones) and discontinue spraying them before harvest or your hops might smell kinda onion-e.

not sure if it'll work with Asian beetles , i have never seen one , but it helps with mites and aphids and such.

(i read somewhere that tobacco is a natural pesticide but i haven't tried that yet)

hopsoda said:

(i read somewhere that tobacco is a natural pesticide but i haven't tried that yet)

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It's actually Nicotine but nothing substantial confirms or denies any potentially plant fatal interaction with hops. I have tried and had success fighting back a mite infestation using a light, home cooked solution. Basically, I dumped cigarette butts into a used milk jug and soaked them in water. I added some of the butt spray to a dish soap solution and sprayed only the affected plants.

the mites went away but, the plants suffered. the infestation was ciught late so it's impossible to say if it was the damage or the nictine that made the plants sick.

I'd use it again but, only as a last resort.

Any verdict from those who've tried the motor oil method yet?

I've got an organic pesticide that I use on all of my vegetables. It kills pretty much everything, including japanese beetles. When I get off work, I'll check the brand name and post it.

cactusgarrett said:

Any verdict from those who've tried the motor oil method yet?

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I just tried the motor oil method... doesn't work. We've got some Jap beetles eating our garden... they particularly like broccoli leaves. I put a little left-over oil from a recent change in an open plastic container under the broccoli. No beetles in it at all after 5 days.

So far (knock wood), the beetles aren't near as bad as they were last year... they were everywhere last year. I'm hoping the milky spore I put down last fall is working. It seems like it is, unless a major emergence is yet to come.