Japanese Beetles

Every year I am in shock of just how bad these pests are. Last week I was filling 2 beetle bags per day. Each bag holds about 1,000 beetles. All of my neighbors did the same. It is unreal.

I have just about given up on finding a rose flower that is not devoured, however, does anyone know of any roses with resistant foliage?

Someone told me that JBs avoid Rosa Rugosa foliage (not the flowers). Is there any truth to that?

Thanks for your help.

Gee, Shane…why so many? Have you set up those JB traps with the bags under them? If so, that’s probably why you have so many. Stop trapping them, and you’ll probably have fewer bothering you. The key word is “fewer”–but you’ll probably still have plenty.

However, if you can keep them from mating and laying eggs, you’ll see fewer next year. It’s a war of attrition. I had a lot of them for 3 or 4 years, but I kept after them and have had very few in the past 5 years. I have caught and killed probably a dozen this year.

And even persistence isn’t fully successful. I have read somewhere that the larvae develop at different speeds and that JBs are a bit like cicadas. Some cicadas are on a 7-year cycle, some, on a 9-year cycle, and so on to 17 years. I don’t know what the corresponding lengths are in the JB cycles, but chances are good that some long-termers and some shorter-termers will all emerge at the same time some year and I’ll have a lot of them once again in spite of my tactics.

But you were asking about JB-repelling rose varieties. I don’t know of any. My rugosas were equal-opportunity meals when I had a lot of JBs. I think some varieties probably attract fewer at some times because of their color or maybe because they aren’t growing actively and don’t smell as good or look as good to the JBs. Some that I thought were JB-free one year got hit later in the year when they were growing more, and got hit hard the next year too when they were growing. Those that are not putting on new growth seem to attract fewer.

Anyway, that’s what I don’t know about it. Persevere, and–good luck! I don’t know where you iive, but I’ve heard from several people who have had a lot of the devils this year.

Peter

Hi Peter,

Wow, only a dozen…dare to dream!

I really wish I was exaggerating about the number of beetles here. I would not believe it if I did not witness it.

OK, so Rosa Rugosa is a bust.

Anyone else? What about the scented foliage roses?

See:

http://desertratrose.com/roseforum/viewtopic.php?t=3003&highlight=

Link: desertratrose.com/roseforum/viewtopic.php?t=3003&highlight=

I’ve been told by Pat Henry at RU that JB’s seems to be particularly attracted to ‘Callista’. I suppose this makes sense now that I read they are attracted to highly perfumed light colored roses and this one was bred from Abraham Darby.

It all adds up. What a shame.

I am not surprised about Callista. Abraham Darby is a lost cause when it comes to beetles.

While beetles are certainly attracted to light colored and fragrant roses, there is something in the leaves that attracts beetles just as strongly as the flowers. Rosa Multiflora, Rosa Glauca and Carmenetta are especially attractive to beetles, despite not having any flowers. Rosa Multiflora seems to be their favorite.

Shane,

Your beetles are not just from your property, but I’d expect you’ll find some seriously skeletonized trees within a mile or so. In my area, Pussy Willow shrubs and either Black Locust or Honey Locust trees are the worst victims. If I had either of these (or could find them on neighbors’ property), I’d buy Milky Spore to put under the victim plants. Those plants are going to keep on harboring JBs, and each female JB makes about 40 eggs per year. It might take some time, but killing the sources for your problem is a necessity.

We use the beetle bags and are surrounded by hay fields, so there’s no way we can afford Milky Spore to cover several hundred acres. But drought in spring and fall cam be good. At certain times of spring and fall, the larvae need to be able to move through the soils- and if you have clay soil, the beetles are trapped in droughty clay coffins of their own excavation.

The link below goes to a page of ours with our version of Japanese Beetle traps with reusable “bags”.

Link: home.att.net/~rocky-top/id159_more_about_japanese_beetle_traps.htm

Ann,

It sounds like you have similar numbers to me. There are streets in my area where huge trees have been completely stripped down to the very last leaf. I have been trying to figure out what kind of trees they are and I think they are Locust trees…thank you!

Whether I use traps or not, I have about the same number of beetles on my roses, however, it is very gratifying to kill those little boogers.=)

Thanks for the link.

Shane,

Once upon a time I was content to kill them when I felt like it, or I could let them be.

Then I read the number of eggs a female could lay in one lifetime, and I did the math.

That knocked me out of complacency. Now I kill them as soon as I can. Full stop.

Do the math of leaving the bugs on just one rose bush and see the numbers ten years later without intervention.

Ann