Cankerworm moth puts Ashe oaks at risk

Wil Petty Staff Writer

October 31, 2013

The annual cankerworm moth infestation has arrived, and the local Agriculture Extention office is offering tips on how to fight the problem.

The moths, which appear during the fall season in the High Country can destroy trees if the right procedures are not followed.

“The best way to protect against (cankerworms) is tree-banding,” said Travis Birdsell, an agriculture extension agent in Ashe County. “The female moths do not have wings, so they have to crawl up trees to lay their eggs on the twigs and smaller branches.”

Birdsell said that when spring arrives, the eggs hatch and the baby caterpillars feed on the leaves.

“In most cases, the cankerworm does not kill the trees,” he said. “The tree defoliates and causes a thinner canopy. Over time, that will weaken the trees.”

Tree bands are layered with a sticky residue which prevents female moths from being able to climb up the tree. It is important to wait until most leaves are off trees to band in order to prevent the leaves from getting stuck.

A tree that is deprived of leaves lacks the nutrients it needs to survive.

“Repeated defoliation of the tree deprives the trees of nutrients they need to make,” Birdsell said. “Over time, the defoliation can lead to a decline in the tree and lead to secondary problems.”

Birdsell said the cankerworms are a problem in the county and he saw the moths were on his oak trees.

“More than likely they have been there for a couple of years, bur one particular tree was defoliating at the top,” he said. “I was able to confirm it was from cankerworms.”

With the lack of nutrients that the tree receives when it is infested with caterpillars, there are several risks the tree can face. For example, if there is a drought combined with the defoliation, the tree can start to rot and face a decline.

“Secondary problems can open a tree,” Birdsell said. “Once a tree is stressed, it can be open to other insects and disease problems, like how the flu can open a person up to pneumonia.”