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Japanese Beetle Strategies

Posted by John Zydowicz 
Japanese Beetle Strategies
July 26, 2013 05:52PM
I'm curious about who here is affected by Japanese beetle, your experiences, and what strategies you use to deter them from eating all your plants. In bad Japanese beetle years, I think the phrase "You can't stop them; you can only hope to contain them" seems fitting.

The beetles have been in this area for at least 10 years, and their population has been high for maybe 5-7 years.

Here's my experience:
2011: Average beetle emergence – Fourth of July? It seemed like a particularly big year. I was working at a vineyard at the time, and within a few days of emerging, the beetles had completely covered the border rows. Their numbers were easily in the tens of thousands. We were working a few rows away, and any time we would touch a vine, the beetles would tumble off and fly in every direction. I got used to the feeling of pokey legs on my skin as the beetles fell down my shirt. Not exactly my idea of a fun time, but hey. Anyway, one particular row at the edge of the vineyard bordered a neighbor's hayfield, and that's where the damage was the worst. To me, it seems Japanese beetles tend to do the best in untilled ground (like hayfields) or fertile/irrigated grass (suburban lawns, golf courses). And they have clear preferences. It seems the more wine grape (V. vinifera) in the plant's genetics, the better. These vines were Marechal Foch, a French hybrid, and the beetles loved them. Meanwhile, the leathery-leafed Concords were untouched. The combination of preferred plants in a border row adjacent to perfect beetle ground led to a perfect storm of beetles. At the vineyard, the strategy was simply to blast the orchard with Sevin, which created a rain of Japanese beetle carcasses. Not exactly a satisfactory approach when trying to grow healthy fruit.
Late summer/fall of 2011 was pretty dry in this area, which also happens to be when Japanese beetles are laying eggs, and larvae are feeding in the soil.

2012: Earliest beetle – June 15th, average 1-2 weeks later - the dry weather carried into spring, with below average rainfall, followed by basically no measurable rain from mid-May to mid-July. Japanese beetles were definitely present, but nowhere near previous levels. However, my observations were made about 100 miles south, and on apples, not grapes, so it’s difficult to compare. A combination of neem oil, surround coverage, and a couple sprays of PyGanic on border Honeycrisp seemed satisfactory (following Michael’s recommendations from The Holistic Orchard).

2013: Earliest beetle – June 26th – Average 2-3 weeks later – Low number of beetles, even compared to last year. Very minor damage on Honeycrisp, roses, basil, etc., but I just haven’t seen many beetles. Biweekly neem sprays, heavy surround coverage on Honeycrisp only, and a single spot spray of PyGanic on actively feeding beetles in Honeycrisp rows.

Anecdotal observations:

Drought/weather has major impacts on Japanese beetle population. I’m guessing the beetles have a difficult time emerging through dry, hard soil. During the drought, the ground here was like cement. Another effect could be desiccation of larvae and pupae in the soil, leading to fewer adults.

Border rows have the most feeding. This is especially true adjacent to hayfields, lawns, etc.

Surround is effective, but it needs to be layered and put on heavily. I totally covered the Honeycrisp trees this year (nonbearing, so didn’t need to worry about washing residues off), and I observed Japanese beetles walking sluggishly, not feeding, just sitting there, and reluctant to fly away unless I touched them (this is at all times of the day, so it’s not just their normal morning sluggishness).

Neem may have repellent/deterrent effects, but it’s difficult to measure. Sluggishness could be related to ingesting neem too. PyGanic seems to work fairly well for spot spraying border rows and preferred varieties, but I wouldn’t want to overuse it. I think it’s important to kill “clusters” of feeding beetles, otherwise they will attract more and defoliate individual trees, which can be a big setback.

I’d really like to see how the organic/holistic methods will do in a bad year for Japanese beetles, but for now, I’m counting myself lucky.

Anyone else have experiences with this bug?

Orchard Ridge Farms
Zone 5a in northern Illinois
Re: Japanese Beetle Strategies
July 28, 2013 10:15AM
Yes, we have them here as well. Neem applications seem to be helping, although this year populations do seem to be much lower, I suspect the same thing, two dry years in a row. Does this mean next year will be a bad year ? The main thing I did in my small orchard is to cut down my plums and my one sweet cherry. The beetles would defoliate them twice a year, and then molest my apples and peaches. So I figured they were the big draw and got rid of them. So this year, the only tree that has much problem is Honeycrisp, and also my Lodi, once the Lodi's were ripe the beetles ate a third of them before I had a chance to pick. Never used Pyganic, maybe I should try that.
Re: Japanese Beetle Strategies
July 30, 2013 10:20PM
We have had significant Japanese beetle problems here in Eastern Iowa since 2010; I think they arrived in this part of Iowa around 2007 or s0. Last year was terrible: peaches were a month early, beetles right on time (about July 1) so they coincided, and I discovered just how much they love ripe peaches, dozens swarming on a single peach, probably 2 or 3 hundred beetles per tree, for about a 2 week period. It was also a terrible drought. And this year I didn't see any in the orchard till July 10, a few on 2 apricot trees and our one sweet cherry, and they were gone in about 5 days. Since then, a few on raspberries and arronia berries. I might have seen 60 or 70 total the whole month of July.

Last year I started by knocking them off the branches into a pail of soapy water in the morning or evening, but that quickly became infeasible. They were too numerous, and knocking one branch shook more onto the ground than into the pail. So I resorted to Pyganic, spraying with a little hand sprayer right onto clusters of beetles. Seemed to kill them pretty quickly.

They clearly didn't like the leaves with Surround on them, but I don't like covering ripening peaches with clay. It does not come off. And I used summer sprays of neem oil, but that didn't seem to affect them. But since they overwinter in the ground in my orchard and nearby fields, I assume that what I really want to do is kill them, not just send them somewhere else to reproduce. Hence the Pyganic strategy. They tend to congregate in clusters, so it doesn't seem like you end up using that much if you can spray right on the beetles, and anything you spray on the foliage is just wasted, so covering a tree doesn't seem to be the way to go. I am hoping that this approach minimizes harm to beneficial insects.

Turkey Creek Orchard
Solon, Iowa (zone 5A)
Re: Japanese Beetle Strategies
July 23, 2014 06:41AM
After a teasing delay, the stinkers are back. We did drop a load of milky spore out there this spring, and are about to set out traps as well. I have toggled about the trap thing, but I really think now, that a dead beetle is a dead beetle. Maybe this is a place where there should be funding to have a mass trapping county wide.

Some ideas- We really let things grow this year, only now mowing areas after a long break. The beetles are being found and feeding on a large number of species, including plum, wild and domestic black and rasp berry, grapes, roses evening primrose, etc, etc. Damage really is spread out, and generally unnoticeable despite having encountered thousands of them. Reflecting on my travels to customer's homes, I remember leafless fruit trees and bushes, in a landscape nearly naked except for these plantings. This may be often repeated, but in a desert with a single well, many mouths will soon make it dry.

Second, entomologists use light to attract many species of beetle, particularly mercury vapor or uv light. Many are active in the evening. Trapping at the light periphery apparently works well. This may be worthy of experiment for borers, jap. beetles and chafers.

Walden Heights Nursery & Orchard
Zone 3 in Vermont
Re: Japanese Beetle Strategies
July 25, 2014 11:23AM
July is almost gone and I have yet to see the beetles in any numbers; one beetle on a grape, another on a raspberry, none in the orchard, even the one remaining sweet cherry (they defoliated and killed 3 young sweet cherries in previous years). We had a dry fall followed by a very long and very cold winter, followed by a very wet spring.

Turkey Creek Orchard
Solon, Iowa (zone 5A)
Re: Japanese Beetle Strategies
May 09, 2015 05:53AM
Good news folks! There is now available a new Bacillus thuringiensis (Bt) galleriae, with activity against turf grubs (mostly scarab beetles of which Japanese beetle is a member), some weevils (pecan, chestnut?, trialed on plum curculio at MSU with no demonstrated effect), and some beetle borers (emerald ash borer, for one). It is available for ground use as boreGONE. Even better it can be used for adult feeding of Japanese beetles foliarly; in the beetleGONE formulation. The ground form could be used on "turfed" areas for first season knockdown of population, but it has little carry over action. if any. to the next year, and is probably cost prohibitive as well. Meanwhile milky spore could be applied as it takes time (a few years) for the population to build and control long term; with only one application. Parasitic nemas can be used as well for immediate knockdown of grubs.

Bt g, is produced by www.Phyllom BioProducts.com in CA; contact person is Kurt Schwartau@Phyllom.com It is available from www.GreenearthAgandTurf .com of Branford, CT; a very nice mom and pop wholesale company with lots of effective nonchemical products, for landscape industry, and some very useful for orcharding also, including Mycotrol O, insecticide labeled for plum curculio.

other management techniques, trapping, etc. to follow with an edit. Had previously composed it all prior to knowing about Bt g; but lost it before posting due to a mis-keyed entry.

Edited 2 time(s). Last edit at 05/14/2015 05:32AM by Dan Lefever.
Re: Japanese Beetle Strategies
May 09, 2015 07:54AM
Interesting! Mycotrol O is also effective against Brown Marmorated Stink Bug. And with the emergence of our new pest - blackstem borer (an ambrosia beetle) - the need for effective organic controls is rising.Even conventional controls don't work all that well against these two. Do you have a web address for PhyllumBio - Google couldn't give me one (imagine that!). Thanks.

Mike Biltonen, Know Your Roots
Zone 5b in New York
Re: Japanese Beetle Strategies
May 14, 2015 05:45AM
See edit corrected post for proper name and website for Phyllom BioProducts. Sorry about that, trying to do it by memory is not always accurate.
Grandevo by Marrone Bio a chromobacteria and ferment product has some activity against plant bugs (labeled) and BMSB (which is not labeled) for it specifically; because it was not effective enough to warrant it I guess. I was told this about BMSB by one of Marrone's product development researchers.
Re: Japanese Beetle Strategies
July 09, 2017 09:59AM
Up until this year my strategy was to go through the orchard as many times a week as I could find time, and tree by tree shake and swat them off branches and into a bucket of water held below. Well, the trees are starting to get too tall for that so something had to change. Enter nematodes.

I bought the triple threat pack from Arbico and sprayed in May. I have yet to see a single beetle to date. Hopefully I have not just jinxed myself. Usually they are out and about by now. Perhaps they are sleeping late due to the extra rainy spring and summer to date? Anyone else trying nematodes on them? In general what is your beetle load this year?

If I am seeing results, it is stupendous, as I was easily collecting hundreds of beetles each session this time last year. Right now, I am being lulled into a sense of security….

Lakes Region NH @ 1200' or so

393 planted towards a 440 goal mixed apple, pear, plum and apricot...
Re: Japanese Beetle Strategies
July 09, 2017 12:13PM
The beetles arrived here in Iowa on schedule, July 1, in substantially larger numbers than last year, but last year we had very few. Glad to hear about other solutions. I am also past the point where I can knock them into a pail. I spray the beetles themselves every evening with Pyganic. They are on Aronia berries, hazelnuts, cherries and certain varieties of peaches, none on pears, only a few on apples. Numbers are diminishing, but there could be a resurgence, or two, if past experience is a guide.

Turkey Creek Orchard
Solon, Iowa (zone 5A)
Re: Japanese Beetle Strategies
July 18, 2017 06:37PM
Inspection of the orchard last Thursday showed no signs of beetles. Yesterday and today were a different story. They are numerous enough that I can not claim to have managed them through nematodes. It may be that my application was doomed to begin with. They arrived on May 2nd, and the weather for the next two weeks proved to be colder and wetter than normal. Instructions on temperature limits for applications were not being met, so I held off until the last couple of days recommended for storage after delivery. Forecast said that overnight it would hold above 45 F. So I sprayed. I woke up the following morning to find a coating of snow on the ground. Not optimal.

I am going to try milky spore next this fall….

Lakes Region NH @ 1200' or so

393 planted towards a 440 goal mixed apple, pear, plum and apricot...
Re: Japanese Beetle Strategies
May 25, 2018 03:35PM
Hello, all -

Has anyone had success controlling Japanese Beetle by increasing their resident population of the wasp, Tiphia vernalis? We have issues with beetles on Honeycrisp and Lodi (just like Jeff mentioned above a while back in 2013). However my biggest frustration has been managing them in our small table-grape vineyard.

This spring I planted peonies in the center of each grape row. Hoping to make some difference starting next spring. But I'm wondering if anyone else has tried this?


Door Creek Orchard
Zone 5a in Wisconsin
Re: Japanese Beetle Strategies
July 05, 2018 04:45PM
Never heard of these wasps before, I looked on line and could not find a way to order them.

The beetle population in my orchard has exploded over the past few years. They usually only have a taste for my cherry trees, grapes and one variety of apple but this year they are on every apple tree.

I've coated my smaller, younger trees with Surround as a deterrent and that works okay unless they really like the tree, neem oil seems to have little or no effect on their eating.

I'm building a mass trap to try and cut down the population for next year.
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