Japanese Beetle

Japanese Beetle

Part of Ep. 1102 Root of the Problem

UW-Extension entomologist Phil Pellitteri discusses the invasive Japanese Beetle.

Premiere date: Jun 25, 2003

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
We are in my old stomping grounds, Pheasant Branch Nature Preserve in Middleton. This is where I grew up. Of course when I grew up it wasn't quite so lush and green and when I grew up here we also didn't have the problem of Japanese Beetle. I'm with UW-Extension Entomologist Phil Pellitteri. Phil, show me these dreaded, cursed monsters.

Phil Pellitteri:
Well the first thing I think you notice Shelley is the feeding. And here we have wild grape which is one of its preferred things to feed on. And you get this real lacy affair type of feeding and eventually this whole thing will turn brown because of it.

Shelley:
Well, I don't like wild grapes, that's fine with me. But is that the critter then on there too?

Phil:
Yeah, the beetle itself is a little metallic and coppery shaped beetle. It has these little white spots on the side.

Shelley:
They're really pretty.

Phil:
Yeah they almost could be a piece of jewelery.

Shelley:
Earrings. And their favorite food is grapes?

Phil:
Well unfortunately their favorite food is almost 300 different species of plants and we find that grapes, raspberries and roses are high in the general plant group. And then in trees we find Lindens, Crab Apples, Redbuds, Birches all get fed on.

Shelley:
Uh oh. So Japanese Beetles love a lot of our popular home landscape plants.

Phil:
Right, and unfortunately they're flying from the 1st of July to the 1st of September so you have two months worth of these coming in and then there's another whammy to them is that they lay their eggs in your lawn and their grubs are a turf pest.

Shelley:
So are they killing? I mean I don't mind if they kill a grape but are they killing our trees and shrubs too?

Phil:
Mostly this is cosmetic. I mean if you have a rose bush they'll eat the buds before the flowers come up so it will have an effect there.

Shelley:
So real cosmetic.

Phil:
In the lawn, though, they can get serious enough to kill a lawn.

Shelley:
Wow. Okay, so what do we do about it?

Phil:
Well, here's where it gets frustrating. We have an option of spraying but that only lasts for three or four days.

Shelley:
Sure. And they're here two months.

Phil:
Right. You can physically protect the plant by using some kind of floating row cover, but again, you know to have your whole backyard covered with this is going to be rather difficult.

Shelley:
And then you can't see the roses either, so.

Phil:
For trees there are systemic insecticides that can be put on, but those have to go on in June before the beetles show up, so that's an option. But I think what we're probably looking at, if you don't like a high maintenance kind of plantscape then you're going to look at growing varieties that are less susceptible.

Shelley:
So are there some out there? I mean are there trees?

Phil:
Oh yeah, definitely. In the tree group you could talk about Ashes and Maples, they don't get fed on. And so that's an option. Where it's going to get tough is people that like the roses, because there's really very little that can be done with those.

Shelley:
But that's where we go to our local nursery person and say hey, what don't they like to eat?

Phil:
Right, get some recommendations, right.

Shelley:
Okay, you're holding one of these traps, the Japanese Beetle traps. I see these for sale everywhere. Is this not a solution?

Phil:
Well, the traps work quite well in the sense they lots of beetles. And they work without chemicals, they use a floral attractant and a sex attractant and the beetles literally come bopping into here and they fall in and they can't get out. And you can catch a tremendous number of beetles in a very short period of time.

Shelley:
Whoa!

Phil:
Now this makes you feel good because you're getting a lot of beetles, but unfortunately the ones that you don't catch lay their eggs in your lawn and you find out you get more problems in your lawn when you use traps than when you don't, and also the beetles you don't catch will also feed on your plants and so you literally are kind of aggravating the problem over time.

Shelley:
So literally when you use a lure, you are really luring them into your yard.

Phil:
Right.

Shelley:
You're not necessarily getting rid of them.

Phil:
They're a great monitoring tool to tell us when they first get into an area, but after that they really do cause some problems.

Shelley:
But you said actually you can use grapes to monitor too.

Phil:
Yeah, grapes are probably the most sensitive plant that I know and so if you want to know if they're in an area you look for that kind of feeding.

Shelley:
Okay. And what parts of Wisconsin do we need to worry about?

Phil:
Well, the southern counties in particular. You know, Rock and Walworth, all the way up into Milwaukee we have problems in the Madison area. Up in Waupun, and we also see them up in Wisconsin Rapids. There are problems as far north as Eau Claire, and we're even starting to get beetles in Green Bay now.

Shelley:
Okay. Now and you said that because they're killing the lawns that is something we may want to deal with a little bit more.

Phil:
Right. They'll eat the roots off and so the lawns, especially in August and September we see the biggest amount of damage. It gets a little complicated for treatment. There is both a rescue treatment if you catch it late, there is also a preventative treatment. But you can look at our website and we can give you some information as far as how to decipher what to use and when.

Shelley:
Okay, great.

Well, we've covered some serious plant problems today, but we've also given you some solutions. And weren't those Alliums beautiful? I won't tell you how many I ran home and planted in my own backyard, but it was a lot. I think the deer are going to be very angry with me next Spring. I'm Shelley Ryan. Thanks for joining me, and I'll see you next time on the Wisconsin Gardener.

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