Banding trees in Charlotte appeared to have worked: Cankerworm population is down

It’s an annual tradition in Charlotte. Cooking up a big Thanksgiving dinner, shopping for presents, decorating for Christmas and — banding your trees to battle the cankerworm.

The pesky, lime-green, leaf-eating worm makes itself most annoying in the spring, when millions of them drop from the trees of Charlotte, littering your porch, hitch-hiking on your dog, or even worse, getting caught in your hair.

The good news: after spending decades and millions of dollars battling the insect, it appears the city of Charlotte may actually have conquered the canker.

Update on April 1, 2020: A count just completed recently saw only 117 moths in more than 300 traps around the city. That’s down more than 99.5 percent in four years. This is typically the time of year you or your dog would be covered with the green worms after a five minute walk.

The city tracks the number of cankerworms annually each spring at 163 locations. The numbers show a dramatic decrease:

• 2016: 38,948

• 2017: 32,434

• 2018: 4,963

• 2019: 184

• 2020: 117

For those of you who prefer math, that’s a 99.5% decrease.

“While we don’t know for certain what the cause is, our best guess is that in back-to-back years, we had several consecutive nights of hard freezes in early spring that may have killed the newly hatched caterpillars at the tops of the trees, as well as the foliage in the trees that they need to feed on,” said Laurie Dukes, assistant city arborist.

Besides being a nuisance, the cankerworm is a voracious eater, chowing down on the leaves of the city’s larger trees. The sheer number of worms can severely damage or kill these old and fragile trees.

For not, the dramatic decline in the cankerworm population is munching away at profits for some trees companies. But there’s still a good opportunity for populations to rebuild over the next several years.

Still, the city isn’t going to roll out a “Mission Accomplished” sign at the Government Center.

“The cankerworm is a native insect, so it will never be completely gone,” Dukes said.

Tree experts say it will only be a matter of time until the Joey Chestnuts of leaf eating are back at it.

“We’re getting a short reprieve from the cankerworms, but stop short of saying we’re done with them,” said Heartwood Plant Healthcare Manager Stephen Clough.

The city is asking for help. The first couple of weeks in December is prime time for residents to band their larger, older trees, such as Willow Oaks. Smaller, ornamental trees do not need banding. The gooey bands stop the cankerworm in its tracks before it can make its way up the tree and lay hundreds of eggs.

Several tree companies, such as Heartwood Tree Company, AAA Tree Experts and Silverduck Tree and Yard Service offer this service for a fee if you don’t want to get sticky yourself doing it.

For more information on how to band the trees, visit the city’s website.

This story was originally published December 6, 2019 at 5:45 AM.