The spruce beetle invasion’s exhausting toll on Southcentral Alaska property owners

One of the reasons Glen Hemingson bought his home in Anchorage’s Fairview neighborhood was the thick stand of spruce trees in the front yard.

“It has the feeling of a forest,” Hemingson said.

But soon, the number of trees shrank as some were culled due to an infestation of spruce beetles — the insect destroying Southcentral Alaska trees, from beloved backyard timber to tracts of mountainside forest.

For property owners, the beetles present a vexing scenario as some scramble to keep their trees alive with extra water and pesticides. Others mourn the loss of the recently dead and embark on the oftentimes costly removal process to keep the beetles from moving to nearby trees and reducing other hazards posed by dead trees on the property.

During a few dry summers, Hemingson began to see the beetle infestation rear its head. The biggest, oldest tree was the first to go.

“It was dramatic how quickly that happened,” he said.

He noticed the tree’s needles turning brown before fall winds blew them off. A tree service arrived to take down the tree and pointed out another tree that appeared to be on the brink, Hemingson said, so they took them both in a day.

Since then, he’s created an outdoor table by setting a round glass tabletop on one of the remaining stumps nestled among the trees. On a recent overcast Wednesday, he walked beneath hanging lanterns strung between other spruces that were still standing, pointing out three that have started to show the telltale signs of a new infestation.

“It’s just part of the life cycle,” Hemingson said.

Spruce beetles are a native species that go through outbreak cycles, which is what’s happening right now, said Alex Wenninger. She’s an integrated pest management technician at the University of Alaska Fairbanks Cooperative Extension Service who works with the public on controlling pests and caring for trees.

In non-outbreak times, the beetles would only attack fallen or weakened trees.

But spruce beetles can overwhelm live, healthy trees under the right conditions. She said that anything that puts stress on trees, including hot, dry, climatic changes, can make it easier for the beetles to overwhelm a tree’s defenses.

Here’s how that works:

Between May and late July, adult spruce beetles bore into the tree and lay eggs. Then their offspring — spruce beetle larvae — feed on the tree’s phloem tissue, the sometimes green, sappy layer just below that bark. It’s also the layer that takes nutrients around the tree.

“As those larvae underneath the bark are feeding on that phloem tissue, they’re effectively girdling that tree and making it so it can’t transport nutrients anymore,” Wenninger said.

[A creeping mass of insect larvae near a Denali lodge raises the question: ‘Am I hallucinating?’]

There are a few options for tree owners trying to blunt the beetle’s onset.

Wenninger said it’s essential to give spruce trees extra water. Even though it’s not guaranteed, water helps defend against insects and diseases.

Additional water is a preventive measure but not a treatment for already infected trees, said Jen Schmidt, a research professor at the University of Alaska Anchorage’s Institute of Social and Economic Research.

“Once your tree has been infected, it’s kind of too late,” Schmidt said. “So if you are starting to see signs of beetle activity or dust around the trunk, you’re going to eventually have to probably take that tree down.”

For high-value spruce trees, some pesticide options are 100% effective when applied the right way, Wenninger said.

She also recommended cutting and processing trees in fall, winter and early spring — before or after the spruce beetles fly, usually from May to early August.

“Every day, we’re looking at spruce trees that are either dead or heavily infested and will die around Anchorage,” said Mike Post, who owns Tall Trees, a local tree service.

He said that the cost to take down spruce trees varies depending on multiple factors, including size, quantity and location within the property. The least expensive option, having a service cut the tree down and clean it up yourself, costs roughly a few hundred dollars. But if the service removes branches and wood or grinds the stump, or if a tree is particularly tricky, additional costs can pile up.

When Jeff Lathrom moved onto his 10 acres property north of Palmer, it was entirely undeveloped, and filled with spruce trees. But soon, the invasion began, as beetles killed hundreds of trees on his “wilderness farm,” where Lathrom, his wife and three daughters keep sheep, ponies and chickens.

At first, Lathrom said they had 10 trees more than 2 feet in diameter, old trees with well over 150 rings. Lathrom said he didn’t notice any die-off during his first year there. But that didn’t last long.

“The next summer, all of a sudden — I mean, it was craziness, how many were dying off,” Lathrom said. “And it started with the largest trees, the oldest trees, which was really sad because they were the biggest and the most beautiful.”

Within a few years, every tree with more than a 7-inch diameter had died. Now, the Icelandic sheep mosey around a clearing where many of the trees once stood.

“It was covered in spruce,” Lathrom said as he motioned across the flat clearing. “And when they died off, it was like, ‘Well, now what do we do with the land? Well, that’s where we’re gonna build our barn.’ ”

The biggest problem presented by the beetles for Lathrom is wildfire danger. Beetle-killed trees become dry, standing timber.

“All it would take is one little spark, and it would just go right through your property like crazy,” Lathrom said. “You try to cut it down as fast as possible. But if you’ve got hundreds of trees that need to come down, that’s also almost impossible.”

Lathrom cuts the trees down himself every summer and fall, one at a time — a task that can take multiple weeks. Fortunately for him, he and his family burn the dead trees in their wood stove, but even that doesn’t take care of all the trees, he said

He hadn’t noticed any new beetle kills this spring, and the insects appear to have consumed what they wanted to consume, Lathrom said. The population will start to die off — hopefully.