Beetles released on Signal Mountain in attempt to save hemlocks

photo Signal Mountain resident Rob Richie, left, holds a jar with 200 predator beetles set for release Friday at Rainbow Lake. Dr. Jukie Kajita, right, research assistant professor in the University of Tennessee at Chattanooga's Department of Biological and Environmental Sciences, looks at the jar with Sofia O'Neill, 2. Members of the Signal Mountain Hemlock Conservation Task Force were in attendance for the release.

A thousand beetles were flown all the way from Washington state in hopes that they'll be able to save hemlock trees in Tennessee.

A different bug -- the hemlock woolly adelgid -- has been devouring those trees into nonexistence. The battle against the bugs has raged for nearly a decade, says Barbara Womack, vice chairman of the Signal Mountain Tree Board.

On Friday afternoon, members of the tree board and the Signal Mountain Hemlock Conservation Task Force released the last 200 laricobius nigrinus, or LN, beetles into the wild, in hopes that these natural enemies of the woolly adelgid will eat the adelgids that are eating the trees.

The LN beetles were tiny and barely visible in their release jar, stuffed with bristles of needlelike hemlock leaves, but their appetite for woolly adelgids is large; it's the only food they'll eat.

Womack said the hemlock protectors had been trying to contain the woolly adelgids with chemical treatments, but those weren't sustainable and needed to be repeated every five to seven years. With the introduction of the beetles -- and even more beetles are planned to come -- they hope to create a definitive end to the tree-eating bugs.

"It's a big deal," she said of the beetles. "It really is."

Yukie Kajita, a research assistant professor in biology at the University of Tennessee at Chattanooga, headed the project. She said the LN beetles are native to the eastern portion of the United States.

"We needed a native enemy to fight them," she said of the woolly adelgids. "We are lucky to get these beetles."

Kajita said a scientist had to go into the forest in Washington and collect the 1,000 beetles by hand, over a period of about two days. Including travel and lodging costs for him, the price of the beetles came out to a hefty $3 per bug.

We saw this east of our office in north Springdale.

Posted by NWADG on Wednesday, March 25, 2015

Not only that, but the beetle release is the first privately funded initiative of its kind in the state, Womack said. The tree rescuers relied solely on donations, which came out to $3,000 for this release, and they'll need more funds for releases in the future. They hope to release more beetles until there is an established population.

In three years or so, Womack said, they'll be able to definitively see if a difference has been made.

"It's an evolving science," she said.

As for whether the beetles could become invasive themselves, Kajita and Rob Richie, a volunteer for the task force, said it's unlikely based on use of this method in other Appalachian regions.

"The only thing they do eat is the woolly adelgids," Richie said. "When the woolly adelgids die off, the beetles will be gone."

Contact staff writer Hannah Smith at hsmith@timesfreepress.com or at 423-757-6731.

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