Native bug takes a toll on Black Hills pines

A pine looper is an insect native to the Black Hills. They consume pine needles in their...
A pine looper is an insect native to the Black Hills. They consume pine needles in their caterpillar stage of life before turning into a moth later in the spring.(Aleah Burggraff)
Published: Aug. 24, 2022 at 5:46 PM MDT
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The Black Hills, S.D. (KEVN) - Ponderosa pines are usually covered in 4- to 8-inch long evergreen needles.

So, as more and more bare trees continue to pop up in the southern Black Hills, concern grows.

“So, we discovered this defoliation event a couple of weeks ago,” explained Rob Hoelscher, district ranger for the Hell Canyon Ranger District in the Black Hills National Forest.

“Now, defoliation means that the insect is consuming the foliage or the needles of the tree,” said U.S. Forest Service entomologist Kendra Schotzcko.

The culprit guilty of chowing down on pine tree needles is a species of pine looper native to the Black Hills.

“That means it is always present in the hills, but normally it is persisting at a low level and folks aren’t noticing its presence because there isn’t significant or severe defoliation like we are currently seeing in this area,” explained Schotzcko.

Currently, there are about 7,000 acres of trees that have some sort of defoliation.

“It ranges from nearly 100 percent defoliation to less than 25 percent defoliation,” said Hoelscher.

However, this isn’t yet a cause for concern. Although the defoliation can be a stressor for the tree, it won’t necessarily kill it.

“If the tree was in good, healthy condition prior to defoliation, the tree can actually re-foliate, so produce new needles, in next year’s growing season,” said Schotzcko.

Luckily, the pine looper’s infestation period is relatively short.

“Feeding is beginning to wrap up already, so most of the defoliation we’ve seen this year has already occurred,” stated Schotzcko.

As far as officials know, the defoliation is restricted to the southern hills and the next step is assessing and documenting the extent of that damage.