Q&AZ: What’s Turning The Trees Brown in Oak Creek Canyon?

By Claire Caulfield
Published: Monday, October 1, 2018 - 10:50am
Updated: Thursday, June 6, 2019 - 12:48pm

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Leaf damage from the alder flea beetle in Oak Creek Canyon.
Forest Service photo by Amanda Grady

Oak Creek Canyon is known for its scenic hikes, but this summer thousands of trees turned brown.

Karen Gieske is a KJZZ listener and works in IT, but spends a lot of time outdoors. She often hikes Oak Creek Canyon with her husband and loves the winding drive through the canyon as they travel from Sedona to Flagstaff.

It was on one of those drives this summer that her husband pointed out that most of the deciduous trees had brown leaves that were full of holes.

“All of these trees are turning brown and it gets really worse up at the head of the canyon,” she said.

“I noticed a lot of the trees by the river were brown, so I actually looked into water quality reports because I thought it might be contaminated water,” Gieske said. When that didn’t turn up anything suspicious, she asked KJZZ about the trees via Q&AZ.

The U.S. Forest Service also noticed the high number of brown trees, and sent a team to investigate on August 15. It concluded the alder flea beetle was to blame.

Alder flea beetles on a tree in Oak Creek Canyon.
Forest Service photo by Amanda Grady

Alder flea beetle larvae are known as “skeletonizers,” because they eat the tissue of leaves but leave the veins intact.

This is the second consecutive season the forest has seen an infestation of the leaf-eating bug, and affected trees saw 80 to 100 percent of their leaves chewed away.

While the brown, chewed up leaves are unsightly, they're no cause for panic. The Forest Service says trees in the canyon are already starting to re-foliate and it’s rare for trees to suffer long-term consequences from the beetles.

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