Linden Tree and Japanese Beetles

[ronfitch]

Hey all,

I normally hang out in the northern lawn forum and am venturing out today as most talk there deals with grubs (preventative and curative) and I am looking at this from a different angle.

We have a linden tree which gets hit each year by Japanese Beetles for the five summers we have had it. This typically hits in the first or second week of July, though last year we got a second wave later in July and into August.

Over the five summers, We have hit it with soapy water after infestation (multiple times over several days), my wife has literally shop vac'd them off and drown them, I have used a Bayer product (Imidacloprid, but do not have in my notes if it was sprayed on or watered in, though my notes indicate it was about this time of year that I applied it) and Sevin to hit them once they we on the tree.

Of those, the Bayer application was the best of the worst, but still not great. There have been years where we have lost 90% of the leaves on this tree to the beetles; the year I used the stuff with the Imidacloprid, we kept about 50% of the leaves, maybe a bit more.

Given the time frame for this summer, any advice for this year?

Thanks.

[TimmyG]

Traps, traps, traps. I use a few Tanglefoot plastic reusable traps and dual lures placed at the extremities of my property, away from gardens and susceptible plants.

[andy10917]

Sevin is quite effective when applied once a week. It's murderous of the bee population though.

[ronfitch]

Sevin is quite effective when applied once a week. It's murderous of the bee population though.

You're everywhere, Andy.

Sevin as a preventative once a week - coating the branches and leaves - before they show up and through the "typical" period of attack (usually the first and second weeks of July for us, but we did get a second wave last year).

Aesthetics aside, I worry about the health of a tree that keeps losing the bulk of its leaves halfway through the growing season every year. Aesthetically speaking, it is nice to have a tree that isn't picked clean July through November as well.

[andy10917]

Yup, I have a Contorted Filbert that gets decimated if I don't take action - it's one of their favorites. I've had to resort to Sevin at times.

[TimmyG]

I used Sevin for a couple years long ago to deal with Japanese beetles on their favorite food sources (rose of sharon, plum, etc., etc.). But with a lot of landscaping, that was way too much non-selective pesticide, and I had to stop using it any time the plants were in bloom (rose of sharon in particular, which blooms right when the beetles are in force).

The successful solution for me has been the use of traps. Whereas grub control products deal with the grubs in your own lawn, it does nothing to stop your neighbors grubs from becoming beetles and munching on your plants. I stopped using grub control products at the same time as Sevin and switching to the use of pheromone traps. My landscape is much healthier now through beetle season, I'm much richer from not having applied expensive grub control products, the bees are no longer in danger, and our chickens get sun-roasted beetles as a snack.

As long as only a few key plants are at the mercy of the beetles, and they're not in bloom, Sevin is a good solution...if you keep up with the regular applications.

[Kmartel]

I would try an early foliar app of the bayer imidacloprid to give some extended systemic control then use bifenthrin as a clean up if you have an outbreak.

Here we still have 2-3 weeks before beetles show up. That might be enough time to do a soil drench of imidacloprid and have to get up into the foliage in time.


Sent from my iOS device using the Yard Help App

[TimmyG]

Don't even think about applying imidacloprid until that linden is well done blooming.