What is killing the trees? Battling the Wooly adelgid the Smokies

Why the National Parks latest action may lead to Kaiju in the Smokies

They say you have to fight fire with fire. Honestly, I’m not sure that’s true but the say it. But now that I think about it, sometimes you can use fire – and fire breaks – to help use up the fuel faster. That allows the fire to burn itself out. That said, by and large, you battle fire with water or maybe a chemical agent of some kind. 

I don’t have statistics right in front of me. But if I’m guessing, fire is probably the fourth or fifth best method used to battle fire, right before peeing on it. 

Nevertheless, the NPS service is going with the fighting fire with fire method in a battle that has been raging – quietly raging – in the park for nearly 25 years. In order to battle the Hemlock Wooly Adelgid, an invasive insect from Asia that has been killing the park’s Eastern Hemlock Trees since 2002, the Park Service has begun importing and unleashing … another invasive insect from Asia. 

Hemlock trees are … good

Per the National Park Service Eastern Hemlocks are a foundational species in the Smokies forests. They are a key part of the ecosystem. The tree’s dense canopies protect streams, keeping them cool as they are ideal habitats for trout and salamanders and aquatic bugs. 

“Their roots stabilize soil, reduce erosion, and help maintain clean waterways throughout the park.”

And for nearly 25 years they have been under attack by a little bug from Japan. One that likes to eat the Hemlock sap, creating needle loss, reduced growth and eventually death. 

About the Hemlock Wooly Adelgid

The HWA likely arrived in the Eastern United States in the 1950s, imported on Japanese Hemlock trees for landscaping in the Richmond, Virginia area.

They were first spotted in the Smokies in 2002. Since that time, they have caused a significant decline in the Eastern Hemlock population in the mountains. 

Their cousin (?), the Balsam Woolly Adelgid, is an invasive species from Europe that has been attacking the Fraser Fir population in the Smokies since the 1960s. The Fir population has rebounded somewhat. Monitoring in 2024 showed lower densities as the ecosystem is building resilience. This is thanks in part to quality, cleaner soil from reduced acid rain contaminants and genetic resistance.

Meet the rescue beetles

Per the park service Laricobius osakensis beetles, tiny beetles native to Japan, feed exclusively on HWA. The park service says that after years of research and careful approval, they’re now being released at select sites in the park. The introduction is part of a multi-pronged approach eradicate the HWA from the park. 

Over the years, the park has implemented both systemic treatments – individual trees are treated with a systemic pesticide on a 5–7-year rotation – and spray treatments. Trees are sprayed annually in high-traffic areas like campgrounds and picnic spots during the off-season. However, park officials and scientists believe this newer biocontrol method is the most promising tool to fight the HWA.

“Unlike chemical treatments, biocontrol offers a long-term, sustainable solution to the HWA problem. These beetles lay their eggs near HWA colonies, and when the larvae hatch, they feed on the adelgids,” the NPS said in a release. “This biocontrol effort has the potential to preserve an iconic species and protect the ecological integrity of the park for generations to come.”

It’s a bold and interesting course of action. Thousands of tiny beetles hatching in the mountains and going after HWAs is something like Jason goes after teens at the lake. Tiny, unstoppable killing machine beetles.

But is it really a good idea?

Now that I think about it, are we sure we want these things that close to the radiation at ORNL? That’s how Kaiju are made after all? Speaking of Kaiju, why would this lead to monsters like Godzilla or Mothra in the parks? You mean aside from accidentally irradiating tiny killing machine beetles who feast only upon the living corpses of their enemy? 

Well, I was kidding about that. We all know Godzilla couldn’t live in one of our lakes, not deep enough. Except maybe Fontana, but I don’t think it’s a practical location for the giant radiation and fire spewing monster. Not a lot for a Kaiju to do up that way unless he likes scenic train rides. 

However, allow me to tell you about the little old lady – she swallowed a fly. I don’t know she swallowed the fly. But she then swallowed a spider to catch the fly, swallowed a bird to catch the spider and on and on and on. Eventually, she had to swallow a cow to catch a goat. 

You see where I’m going with this. We import a beetle to catch the HWA, then import a spider to catch the beetle and so on and so on and so on. Eventually we’ve got Japanese cows chasing Japanese goats chasing Japanese dogs chasing Japanese cats and on down the food chain.  

Should we be worried about introducing an invasive species to devour an invasive species?

Technically speaking, the beetles being introduced are not invasive, at least not yet. They are simply non-native. To be an invasive species they have to be doing “harm to the environment, economy, or human health.” 

I’m sure there has been extensive testing to make sure that it isn’t possible – or at least not likely – for the beetles to become invasive. I suppose because the beetles feed exclusively on the HWA. So, once the HWA are gone the beetles will die of starvation? I am curious if they will feed on the BWA as well. 

Look, the NPS scientists are incredibly smart. And I’m 100% sure this has been carefully thought out and the reward outweighs the risk. 

However, I retain some small level of skepticism for three reasons: 

• I’m not a scientist and I don’t have all the data. Even if I did, I might not understand it. And I think it was Yoda that said, ignorance leads to fear and fear leads to skepticism. 
• I watched “Jurassic Park” and heard eminent scientist Ian Malcolm explain that “life finds a way.” Could these beetles lead to Velociraptors in the Great Smoky Mountains? If so, the scientists at the NPS can certainly expect a firmly worded letter. 
• I grew up in the shadow of a mighty Kudzu big enough to block out the sun in the summer. Marketed as a way to stop soil erosion in the Dust Bowl, Kudzu is now the second most dominant species in the American South. Now, if we could get these tiny, hungry Adelgid eating beetles to turn there attention to Kudzu after they’re done with the HWA’s we might have something. 

What do you think? Is introducing the beetle a good idea? Let us know in the comments and on the socials!