May 30

The Emerald Ash Borer: Meet the Beetles

This little shiny green bastard is an emerald ash borer beetle. He’s kind of fancy looking, isn’t he, all sparkly like that. But he’s not fancy. He’s not fancy at all. He is a menace. He and his like have invaded this fine North American continent, and they’re wreaking all kinds of havoc.

The emerald ash borer, small and pretty though it may be, is not supposed to be here in this part of the planet. They’re native to Asia, where they fit quite nicely into the ecosystem. They are part of the natural food cycle. They eat, and they are eaten. Here in North America, they’re an invasive species, which is a nice way of saying that they are eco-thugs with no natural enemy to eat them and keep them under control. Any invasive species is capable of doing serious damage, because their populations quickly explode due to the lack of natural predators. And the emerald ash borers have a massive appetite for something we’ve got plenty of around here: the ash tree.

Now, you know the ash tree. There’s hundreds of millions of them in North America. Look out the window right now, and you’ll probably spot one. Here in Michigan, they’ve become incredibly easy to identify, because they’re all dying. And that’s freaking me out.

I love trees. They provide an awful lot for us animals, and don’t ask for a lot in return. At the most basic level, their massive photosynthesis capabilities provide the oxygen we kind of rely on to remain living. They take in our carbon dioxide waste, and breathe out oxygen. It’s a neat little arrangement.

For me, as a homeowner, I love trees because they boost my home’s value. They shade the house, which means I don’t have to spend as much on air conditioning to keep it cool. They provide a home for birds. They provide food for the squirrels and other critters. Hell, they’re just kind of nice to look at. One of the first things we did when we built our house was to start planting trees. And one of those trees is an ash.

The emerald ash borer first started making itself known in southeast Michigan, near Detroit. In 2002, people started noticing that the ash trees that are so prevalent in the area were starting to die off. It didn’t take much investigating to determine that there was a new menace in town that hadn’t been there before, and that this new menace was destroying ash trees. By the millions. The emerald ash borer was here. But how did it get here?

Like most invasive species, there’s no definite answer to that question. But they’re native to Asia, and as you know we get an awful lot of stuff from that part of the world. It gets here on wooden pallets, and lots of wooden containers. Some of that wood is made from ash. Put 2 and 2 together, and well, there you have it. Invasion of the Ash Tree Killers.

What the emerald ash borer does to these poor ash trees is horrible. The emerald ash borer (let’s call it EAB from here on out, ok? I’m tired of typing it out.) larvae burrow into the trees’ bark, and set up shop just under the bark. These little larvae love, love, love them some ash tree bark. And they’re vociferous eaters. The problem? This part of the tree is the highway that carries water and nutrients from the roots up through the trunk to the branches and leaves. Destroying this highway means the tree starts losing its ability to feed itself, and it obviously starts to die. This photo is an example of an ash tree infested with EAB in the process of dying.

From southeastern Michigan, the little EAB started moving and expanding into more and more areas to the point where today there are EAB outbreaks in many U.S. states and Canada. And it’s not slowing down. In Michigan alone, tens of millions of ash trees have fallen victim. And there’s no way to stop them.

Oh, the scientists and tree experts are working feverishly to find a solution. To date, they haven’t been real successful. For a tree infested with EAB, the only thing to do is cut it down. Here in Michigan, the sight of dying ash trees is everywhere, and it’s incredibly sad to see. Streets once lined with giant, beautiful shade-giving ash trees are now lined with the dead, leafless remnants of these once mighty trees.

Thankfully, the EAB is only affecting ash trees. But what a toll they’re taking. Once you start noticing all the dying ash trees, you start seeing them everywhere. emerald-ash-borer-sizeThere are massive, century old ash trees in town here that are being strangled to death by these insidious little bugs. (They really are small for all the damage they’re doing.) Watching this happen is heartbreaking.

While scientists haven’t found a way to eradicate the EAB on a large scale, they have found treatments that are helping individual ash trees fend off these invasive insects. They won’t help protect large numbers of ash trees on a community-wide level, but for homeowners (like me) with an ash tree or two on their property, they may help the tree survive.

ash-treeThis is my hope; the ash tree in my yard is rather young, and not that big, but I don’t want to see it die. So I’ve been taking the scientists’ advice and several years ago began treating it with one of their suggested products, an insecticide called Imidacloprid. It’s the active ingredient in Bayer Tree & Shrub Insect Control. I follow the products’ instructions, pouring a solution around the base of the tree every spring. Most EAB treatments work systematically; the product is introduced into the soil around the tree, where it’s taken up by the roots and spread throughout the tree. Apparently, the EAB larvae don’t like this stuff very well, and keep away.

There are a couple of problems with trying to treat ash trees. First, the treatments aren’t cheap. Whether you use a do-it-yourself product like I am, or hire a tree contractor to do it for you (which you’ll have to if you’ve got large trees), it’s kind of expensive. The Bayer stuff is about 20 bucks, which gives me two treatments. But as the tree grows, more and more product will be needed.

Secondly, once you start treating an ash tree, you can never stop. If you do, the tree will once again become susceptible to infestation. It’s up to the individual to decide whether it’s worth the expense to keep an ash tree alive or cut it down. And treatment is no guarantee. So far, my little ash seems healthy and is growing nicely. But EAB infestations typically take a couple of years before any damage starts showing. Once it does start showing, the tree is typically dead in 2 or 3 years. I’ll keep treating it and hope for the best. This area is heavily infested with EAB, and almost every other ash tree I see nearby is dying. I’m not optimistic about the long-term prospects for my trees’ survival, but I’m willing to try my best.

How is this terrible little insect spreading? An adult EAB beetle can fly up to half a mile from one ash tree to another. That’s one way. But the main way they’re getting around is the same way they got all the way to North America from Asia: Humans. Once again, our species is the main enemy of the natural world. The transport of fire wood or nursery trees infested with these tiny bugs gets them from one area to another quite easily. Municipalities have established quarantine zones around known EAB infestations since they were first discovered, but they aren’t working. There’s no way to enforce fire wood or tree transport; it’s not exactly a ‘high priority’ issue. So it continues.

I’m not sure where this will all end. Hopefully, researches will discover a way to bring the EAB infestations under control in a way that doesn’t do more damage than the bugs themselves. In the meantime, treat individual trees, plant alternative tree species, and for the love of all that is good, DON’T MOVE FIREWOOD !!

To learn more about Emerald Ash Borer, read my piece at Green Home Source here.

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Posted May 30, 2014 by in category "Environment


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