Emerald Ash Borer

Emerald Ash Borer

Part of Ep. 1303 Plant Communities

The Emerald Ash Borer, an invasive species originally from Asia that attacks ash trees, is making its way to Wisconsin. UW-Extension Entomologist Phil Pellitteri tells viewers how to identify trees affected by Emerald Ash Borer and what they can do about it.

Premiere date: Oct 05, 2005

TRANSCRIPT+
Wisc Gardener Transcript: 

Shelley:
This is what you want your ash tree to look like healthy, green and lush. However, you don't want it to look like the one next to me. I would call this one mostly dead. I'm with UW-Extension Entomologist Phil Pellitteri. We have a bug alert. What are we alerting people to?

Phil Pellitteri:
There's an insect in Michigan called the emerald ash borer It is probably an equivalent to Dutch Elm disease.

Shelley:
Wow, it's serious! Is that what killed this ash tree?

Phil:
We haven't found the insect in the state yet. The ash looks the same no matter what kills it. We've had problems with verticillium disease. This has a native ash wood boring insect in it. And one of the things that we look at in figuring out who killed the tree is the size and shape of the trails and the size of the hole that's left behind. A flat headed apple tree borer killed this tree. We're looking for the emerald ash borer. It has "S" shaped type of trail about a 1/4 of an inch in diameter. I often talk about a worm trail on a sidewalk. It's that random "S" shaped pattern. They they leave behind "D" shaped holes. They're about an 1/8 of an inch in diameter. The insect is flat on the back and round on the tummy, so they have a "D" shaped hole. If people see those symptoms on a tree they need to get a hold of somebody and make them aware of it.

Shelley:
What does this insect look like?

Phil:
"Emerald ash borer" describes an incredibly bright green metallic beetle, about 12 millimeters in length. We have many other borers in that same genus. They're really rather difficult to tell apart. If it's dying, and has "S" shaped trails and "D" shaped holes that's when we think we've got the insect.

Shelley:
As you're saying, it's not here yet. We really want people to be on the alert.

Phil:
Right, it was probably in Michigan for about 10 years before it was discovered. They've got 20 million dead trees 17 counties are quarantined. In Wisconsin, about a third of our city trees are ash. If we talk about the trees out in wood lots we're talking 680 million ash so it would be devastating if this insect established. It attacks trees whether they're stressed or not which is quite unusual for borers. It is really a big deal.

Shelley:
And it results in death.

Phil:
Right.

Shelley:
Should I be looking at not planting ash trees any more? I mean, that's one of my favorites.

Phil:
I think the option is one of the trees that have shown some resistance is the autumn purple white ash, which is a beautiful tree.

Shelley:
That is my favorite.

Phil:
It turns out, that if this insect establishes, you could still treat the tree. You would spray the trunk or use a systemic but it becomes a high-maintenance tree. I think that's something you've got to factor in. That if the insect does get here you're going to have to fight to keep the tree.

Shelley:
How is it coming, if it's not here yet?

Phil:
The most likely source is firewood. The DNR has gone back, last year and this year and looked at campground registrations. If anybody came from an infested zip code they have inspected the individual site to make sure the insect has not established yet. So far, we've not seen it. It's possible somebody could move here from those areas. It's not legal to carry firewood But they could be introducing the cities, also.

Shelley:
If somebody sees "S" shaped trails or the green bug what should they do?

Phil:
Get a hold of the city forester, Department of Natural Resources or the Department of Agriculture so an inspector can come out and really verify that that's what's going on. If that's the case, the tree will be destroyed very quickly and we'll inspect the trees around it to make sure that the insect has not spread.

Shelley:
Thanks, Phil, this is very good information. We have an 800 number to call if you do think you see this. Be on the alert.

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