Colored leaves crackle underfoot with every step, while chilly air guides hands to the warmth of pockets. For some, there is no better time to be outdoors than the Fall, especially with the added glow of a campfire

But even a seemingly innocuous activity like building a fire can have a seriously negative impact, beyond the risk of causing a wildfire, if done with no forethought.

The Indiana Department of Natural Resources warns Hoosiers that transporting firewood for campfires could inadvertently introduce invasive pests that are deadly to the state’s native tree population.

State entomologist Megan Hughes said that bringing in firewood from other locations could introduce species of pests that prove devastating to trees in the Midwest, including one of the most invasive species in the country.

The emerald ash borer is a bright metallic green beetle that is smaller than a dime, but has been responsible for the destruction of tens of millions of ash trees in at least 30 states.

The insect is native to Asia and was first discovered in the U.S. in 2002. Since that discovery in southeastern Michigan, the beetle has spread as far as Colorado and Maine.

“We already know that emerald ash borer was moved around quite a bit through firewood movement, actually. That’s primarily how it got into northern Indiana,” said Hughes. “People would go camping up in Michigan where the pest was, and then bring leftover firewood home with them. So, a lot of the entry points that we found for emerald ash borer was actually attributed directly to firewood.”

In the years since, the beetle has been detected in all 92 counties in Indiana.

The state of Indiana imposed county-level quarantines that prohibited the transfer of wood from infested counties, but soon dropped them after the beetles’ spread was too quick to allow effective enforcement. The U.S. Department of Agriculture imposed a state quarantine on interstate firewood movement that was lifted in 2016.

“We know that a lot of these pests can’t move long distances by themselves. Many of them aren’t good fliers, or they just don’t fly very far from where they were hatched. But humans moving firewood can take these things thousands of miles in very short periods of time,” said Hughes.

State entomologists are also concerned that transporting infested firewood could introduce a species of invasive pest that the state has so far been lucky to avoid: the Asian longhorn beetle.

According to the Indiana DNR, the beetle is native to China and attacks a range of hardwood trees, including ash, elm, birch, poplar and willow, but has a strong preference for maple trees.

The black beetle has random white markings on its body and antennae. It can be up to an inch and a half long.

“Asian longhorn beetle has been found in several places in the country, but it’s important to us that it’s been found in the Chicagoland area and in the Cincinnati area,” said Hughes. “In the Chicagoland area they think they’ve eradicated that population, but, in Cincinnati, they’re still working on eradication down there. Over 100,000 trees so far have been destroyed in infested neighborhoods.”

So far, the state has avoided Asian longhorn beetle infestations. Hughes said proper firewood management could help keep the beetle, and other invasive pests, out of Indiana.

“We encourage folks to either buy local or buy firewood that has been either under a federal shield or compliance agreement of some type,” said Hughes.

Buying firewood from local sources minimizes the risk of transporting the invasive pests that may be found in other parts of the country. It can also keep pests contained to an already infested area, instead of letting them expand their reach. Any unused firewood should be left at the campsite and not transported to other areas.

In the state of Indiana, you can bring firewood into a state park, reservoir, state forest or fish and wildlife area only if it’s sourced within the state and has had all bark removed, if it’s kiln-dried scrap lumber with no bark or is packaged firewood with a USDA or state of Indiana compliance stamp.

Hughes also recommends buying dry, or seasoned, firewood.

“If you buy firewood that’s well seasoned, there’s less chance of it being infested with any of these insects, because the seasoning period dries it out long enough for the pests that were underneath the bark or that are in the hardwood to no longer live in it,” said Hughes.

Hughes said she and other state officials recognize that the spread of invasive pests is often inadvertent, but a little bit of knowledge could prevent a lot of trouble for the state’s precious natural resources.

“I think we just need to be very conscious of what we’re moving around in our everyday lives. I think there’s a lot of folks out there that aren’t aware of what they’re doing,” said Hughes. “We enjoy being outdoors, and we’d like to be able to ensure that we can continue to do so. The only way to do that is to help protect it. So, we have to learn about our environment and what’s supposed to be there and what’s not.”

You can report a suspected invasive pest infestation by calling the Indiana DNR at 1-866-NO-EXOTIC. You can also contact them by email. Be sure to include your name, address, contact number and what species you have seen.

You can also find more information about firewood and invasive species at this site.