To answer in reverse, the park tried sprays and foam with th Balsm Wooly Adelgid but it was way too ineffective and way to expensive. So after short trials they just did nothing.
Originally Posted by Dead Drifter
The park continues to fog areas like Cades Cove and other significant areas which is working but far too impractical for widespread use. They have released natural predator insects but this is also just a mitigation not a solution. I believe before it's all said and done there will be many dead hemlocks.
One good defense is that hemlocks grow near water so that aids in their ability to defend themselves. It's like the southern pine beetle from 2000-2004 east Tennessee lost ~75% of all yellow pine. Insects are a hard beast to fight.
In the end trees are our greatest renewable resource. If they die the insects will leave and the trees will grow back.
Remember......I'm and idiot