• Print
  • Reprint or License
  • Share Share

It's the Queen City vs. the cankerworm

City won't spray this year, and infestation could be ‘significant'

By Steve Lyttle
slyttle@charlotteobserver.com

More Information

  • At this time of year, residents have only one course of action available – spraying caterpillar-infested trees. Arborists say the most effective sprays, which are available in garden stores, are those with Bacillus thuringiensis (Bt).

    In late fall, you can wrap bands with a sticky goo around trees to keep wingless moths from climbing trees to lay eggs. Those supplies are available at many area hardware stores.

    Cankerworms attack deciduous trees and leave evergreens alone. Their favorite target is the willow oak, but they'll dine on other trees and shrubs.


The cankerworms are coming, and this time there'll be no help from above.

The inch-long critters responsible for gobbling the foliage on thousands of trees in the Charlotte area will hatch any day and begin their nefarious misdeeds.

Unlike last year, the city of Charlotte will not conduct an aerial bombardment of the tiny caterpillars, and there's little residents can do to stop them from crawling from their nests near the tops of trees and devouring leaves.

“The best time to deal with them was late last fall,” city arborist Don McSween said Monday. “That was the time to band the trees.”

Cankerworms are the caterpillars of a small native moth, commonly found between Canada and Texas. In the fall, they come out of a resting phase, hatch into wingless moths and head for hardwood trees to lay eggs – which then hatch into cankerworms in the spring.

Applying bands around trees prevents moths from climbing and making nests. But that's old news, and now it's time to deal with the cankerworms' coming-out party.

McSween said city workers have been watching trees in recent days for signs of the caterpillars.

“They'll start hatching any day now,” he says.

Based on surveys taken last fall, he adds, the infestation this spring could be “significant.”

In addition to eating foliage and leaving trees – especially the large, graceful willow oaks – susceptible to tree-killing diseases, the caterpillars have other bad habits. Those little black balls you see under cankerworm-attacked trees? Yes, they're what you think they are.

McSween says residents can battle the caterpillars in small trees, such as dogwoods or Japanese maples.

Last spring, Charlotte paid more than $1.1 million for Al's Aerial Spraying to do battle with the cankerworms. This year, we're on our own – us versus the cankerworms.

Hide Comments

This affects comments on all stories.

Cancel OK

The Charlotte Observer welcomes your comments on news of the day. The more voices engaged in conversation, the better for us all, but do keep it civil. Please refrain from profanity, obscenity, spam, name-calling or attacking others for their views.   Read more

Disclaimer