The twisted lines beneath the bark of an ash tree are caused by an infestation of emerald ash borer (EAB). Researchers at Michigan Tech have been studying the invasive species for the past four years. Now the beetles have made their way from Calumet to Houghton.
"It's not unexpected that ultimately emerald ash borer would get to that part of the town, too. We were hoping that it wasn't there quite yet, but obviously it's established in that area now," said Andrew Storer, PhD and Professor of Forestry at Michigan Tech.
Foresters, like Megan Petras, are peeling ash trees and looking for larvae.
"Once we get the logs inside the building, first we'll flick off the bark to look for any eggs that have been parasitized and we'll collect all of those eggs and then we'll start to peel the tree and look for larva, and we collect one larva from each life stage," said Petras.
Once the egg hatches, larva bore their way into the tree. Then the tree can no longer receive the necessary nutrients and it dies.
Once the larvae are collected, they're counted so the researchers have a better understanding of how infested the trees are.
"We do collect some discs out of some of the logs so that we can get ideas of how long a tree had been infested. If we find an old gallery on a tree, we'll cut a disc out of that to do some analysis of growth rings, but the remainder of the material, once it's finished with, will be disposed of," Storer said.
Peeling of the ash trees is a six week project, and Michigan Tech professor Andrew Storer says based upon the research his team is collecting, they will soon be able to see if the EAB population is increasing or developing at a slower rate based on what researchers have done to slow the progression of the beetles.