A Very, Very Expensive Beetle (Only YOU Can Stop 'em)

You may not have heard of the emerald ash borer (EAB), a glittery green beetle with a copper-red belly, but it's notorious among biologists, conservationists, and others who care about America’s forests.

Since landing on U.S. shores in the 1990s, the EAB has killed more than 50 million North American ash trees. Cities and homeowners have spent loads of money on pesticides and tree removal, but until invasive-pest expert Juliann Aukema (and some others) published a study, nobody was sure how much financial damage the beetles were doing. The team’s estimate is baffling: $850 million in local government costs. And $380 million in residential costs. Each year.

EABs drill into ash trees and lay eggs, allowing their larvae to cozy up to the tree’s phloem and xylem and start feeding, effectively starving the host. In a mature infestation, you can see a barkless bit of trunk laced with the EAB’s looping tunnels of destruction. RIP, ash tree.

And it could be your fault. If you build fires, you could unknowingly be an EAB conduit. According to Aukema, tree-killing bugs and pathogens hitch rides to virgin territory on firewood. The chain of events is easy enough to imagine, especially if you saw Contagion: A healthy-looking tree is felled in northern Michigan, logs are trucked down to Chicago, where a peacoated couple buys wood for their new fireplace. Next thing they know, it looks like a beaver’s been chomping around in the backyard. Where'd all the bark go? Your cozy fire suddenly costs a lot more than you thought.

What to do? A website called Don’t Move Firewood encourages people to use only locally grown logs in hearths and campfires. It says the best way to prevent the spread of EABs — and the similarly destructive chestnut blight and Dutch elm disease — is to buy wood that was cut as close as possible to where you'll be burning it.

Meanwhile, Dr. Aukema is trying to tighten up customs policies: “We are pushing for not having them get here in the first place,” she says. “We want to see stronger regulations on wood products to reduce the number of insects that come from overseas. In five years, we could have another EAB on our hands.”

As for you (yes, you): Keep your wood local, and beware of little green hitchhikers.

--Jake Abrahamson