Cankerworms — What They Are and How to Get Rid of Them
If you’ve ever driven through town and noticed the tree trunks are wrapped, it’s specifically to prevent cankerworm infestations. Once all the leaves have fallen from the trees in late November or early December, the wrapping process begins!
To understand why Charlotte works so hard every year to prevent cankerworms, it’s important to give you some background on these pests.
For more than 30 years, the state of North Carolina has seen severe infestations of cankerworms, also known as inchworms. Back in the 1970s, Concord recorded its first minor infestation of these small pests. After that, numbers remained somewhat low. But in 2009, a major infestation was reported south of Harrisburg. The following year, it was confirmed to have spread to parts of Concord and Kannapolis. Since that infestation, Cankerworm populations have continued to increase rapidly each year.
If cankerworms are threatening your lawn and you’re wondering how to band trees for cankerworms, you’ve come to the right place. Let’s kick things off by first discussing what these tiny pests are.
What Are Cankerworms?
Cankerworms are actually a caterpillar, not a worm.
They get their nickname, inchworm, from the unique way they “inch” about with their short fleshy feet. They’re roughly an inch long, and only have feet at the front and back portion of their bodies. This is what causes their unique loop-forming method of walking.
Their color can range from neon green to dark brown with stripes, depending on their age and the season they hatched. Unlike other species of caterpillars, they’re hairless with a smooth appearance.
Related: What Pest Is Killing My Trees?
Why Are Cankerworms A Problem?
The problem starts in the fall, during the cankerworms’ mating season. After mating, the flightless female moths proceed to crawl up the trees to lay their eggs in the highest branches. In early spring, the eggs hatch and the new generation of worms chew on every bit of foliage they can.
Well-known species like elm, oak, maple, beech, cherry, ash, and hickory, are just a handful of the tree species they love to eat. Cankerworms create small irregular holes in the emerging leaves, avoiding only the veins. This weakens the trees and makes them more susceptible to stress (which is already present in urban areas due to pollution), drought, and several types of disease. Not only that, but they also leave behind unsightly foliage. Together, these factors can ultimately lead to borer damage, branch dieback, and root decline.
Fortunately, a mature and vigorous tree will remain healthy if it endures just a single season of cankerworms (sometimes even two). All that will result is a slowing of growth. However, three or more generations of cankerworms attacking the tree can cause major limb dieback. Young or weakened trees likely won’t stand a chance after just one season!
As if hurting our trees isn’t bad enough, these pests are also a nuisance to our general outdoor experience, which is why Charlotteans need to know how to band trees for cankerworms!
How to Band Trees for Cankerworms
Tree banding is the most common method for controlling cankerworms. To band a tree, you first apply a glue product around the tree’s trunk. Next, use a wrapping material to cover the trunk. This will catch the females and prevent them from laying eggs higher up.
For best results, band your trees in late November through early December to ensure all leaves have already fallen. Waiting until the leaves are gone is imperative! Leaves can stick to the band and create somewhat of a bridge, allowing the worms to climb over the glue and continue up the tree. Afterward, you can fully remove the banding come spring.
Still wondering how to band trees for cankerworms? Here are four simple, DIY steps.
1. Choose a banding method.
Bug Barrier, Catchmaster, Stik-N-Stop, and Tanglefoot are all local brands that we recommend.
2. Position your band about four and a half feet up the trunk.
Avoid using staples on small, young, or thin-barked trees. Instead, use electrical tape. Staples on larger trees are fine to use, but never use nails.
A note: Cankerworms prefer to feed on most types of hardwood trees with the exception of evergreen trees like pines, magnolias, and hollies. While smaller trees can be banded, focus your banding efforts on large trees (taller than a two-story house).
3. Maintain your band throughout the winter.
Keep an eye on your band to make sure leaves aren’t clogging the trap or that squirrels haven’t caused damage.
4. Be sure to remove the bands by the end of April
If bands are left on, moisture behind the bands may weaken the trunk, allowing insects easier access to the tree.
Overall, the banding process is non-toxic and safe for any surrounding plants in your yard, and especially the trees. If you’re not up to the task, a professional lawn service company (such as ourselves) can band your trees for you. Allowing experts to complete the job will prevent unnecessary stress to your trees with precise banding.
We all know Charlotte is the city of trees, so our community must proactively protect them from one of the most destructive pests in the area.
More Pests, More Problems
Here at Killingsworth, we think it’s important for all homeowners throughout the Carolinas to understand what pests are out there. Cankerworms aren’t the only destructive pest you should keep an eye out for. To protect your yard and home, you should know the other common pests and the damage they can cause. This way, you’re never caught off guard against a pest!
Protect your yard and schedule an appointment for our lawn care services.
This blog post was originally published in 2015 but was refreshed in 2020.