Hemlocks - Beatles Working
From Crossroads Chronicle
Rosy future for the hemlocks? - Naturalists say their discovery means the adelgid predator beetles are working.
Recently, a specialized predator beetle from Japan, Sasajiscymnus tsugae (known as “Sassie”), was introduced to eat the adelgid, thereby creating a natural balance of prey-predator. The poppy seed-sized “sassie beetle” was tested for three years in a laboratory in Connecticut to make sure the beetle would eat only the adelgid (which it did). Then, beginning in 1995, the U.S. Forest Service began releasing the beetles into the wild, trying to see if they would be able to eat the adelgid quickly enough to save the hemlocks.
The Horans said that recently, the beetles became available to private landowners, so they bought 3,000 of them, and Patrick Horan systematically released them on their 142 acres above Whitewater Falls.
“We didn’t bother taking pictures of the ‘before,’” Noel Horan said. “But before you knew it, all our hemlocks were coming back. The beetles were not only on release trees but flying to other trees.”
But while they were happy to see their trees thriving again, the Horans were saddened because of the increasing number of “gray ghosts” - a dying hemlock takes on a gray color - throughout the Cashiers area.
Their spirits were lifted the week before last, when a chance visit to Cashiers beekeeper Marshall Rice brought an unexpected discovery. Rice’s property, on Hwy. 107 South, is at least a mile from any of the known forest service beetle release sites, according to the Horans. Rice’s hemlocks were already starting to die; he had cut several of them down last year, and he had several more slated to cut down, but he hadn’t gotten around to doing so.
But Patrick Horan noticed two weeks ago that Rice’s previously dying hemlocks were starting to sprout new growth, and the beekeeper had not chemically treated the trees nor released any beetles. Several of the trees were awash in light green needles that signify new growth, from the spring, he said, and were starting to fill in where once they had been sparse. A few boasted darker green foliage and were quite lush, from growth the previous fall.
And when Patrick Horan was able to collect a Sassie beetle from Marshall’s hemlocks, the mystery was solved.
“These beetles are really working,” Noel Horan said.
Patrick said the trees are not completely healthy; they still have a lot of open spaces on the branches.
“But if a tree can produce new growth, it has a chance to survive,” he said. “And because the beetles are here to control the adelgid population, the trees will be protected for the long-term.”
Rice said he is thrilled to see his beloved hemlocks return from a certain death. He relies on the trees to assist with his beekeeping. When the bees swarm, they go to the nearest tree, and they like the dark hemlocks, particularly.
“Last year, there were just sticks sticking up on top,” Rice said. “Now it’s coming back more all the time. I can’t believe it. I was going to cut it down last year.”
Jeff Owenby, forester with the forest service’s Highlands Ranger District, said the Horans’ discovery is “encouraging.” But he wants to wait until Clemson’s entomology department is able to complete its studies on the beetles’ effectiveness before he gets as excited as the Horans.
“I’m still relatively cautious because of the extent of the infestation, and I don’t know how all the studies will come out, so without that knowledge, I’m hesitant [to say this is proof],” Owenby said. “I’m eagerly anticipating the results of those studies.”
David Bates, executive director of the Jackson-Macon Conservation Alliance, said he, too, prefers to wait until the Clemson studies are complete before he considers the beetles release a success. While he agrees that many of the once-infested trees are showing far fewer adelgids, he isn’t sure whether this is because of the beetles or some other reason, including the weather.
But Bates said he is happy the hemlocks seem to be improving.
“Personally, I’ve observed the lookout platform at Whitewater Falls, where a release was done three years ago, and it - and those are Carolina hemlocks - appeared to be much healthier than trees, say, across the vista,” Bates said. “I think the beetles or something has been positively improving the outlook for those trees. I am really pleased, it’s probably a mild word, to hear others have observed that the hemlocks seem to be holding their own or reviving as a result of beetle releases.
“We continue to believe that the combination of the predator beetles and the chemical controls, where needed, will preserve selected areas of hemlocks.” The Horans hope that other people and environmental organizations in the community will consider buying and releasing the beetles in as many places as possible. They say their discoveries prove the beetles are working.
“We’re seeing that they’re spreading, and working not only in the lab,” Patrick Horan said. “It’s so neat to come across this. These trees were dying; now they’re not. It’s a kind of natural experiment. The beetles came in [from one of the forest service release sites] and saved the trees by establishing a natural balance between predator and prey.”