CAnkerworms conquered

Tree program contact

Erin Oliverio, Tree Canopy Program Manager

Call us 704-432-2925

Email us eoliverio@charlottenc.gov

Visit us 701 Tuckaseegee Road, Charlotte, NC 28208

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​​​Fall Cankerworm in Charlotte

Charlotte has a history of severe cankerworm infestations. But in the last three years, cankerworm populations have plummeted. Local arborists believe an extended frost killed the newly hatched caterpillars. This stopped the insect's life cycle, resulting in fewer moths the next season.  

The city will NOT band trees this fall

We recommend homeowners save money by not banding. City staff will be monitoring willow oaks across the city to be prepared when cankerworms reappear. 

The Great Cankerworm Count: Help Us Conquer the Canker How can you help?

Monitor your trees and report cankerworm activity to help us know when and where they make their return. Join in the Great Cankerworm Count.

Seeing black and orange caterpillars on your oaks?
Caterpillars seen in August/September are Orangestriped Oakworms. These black and orange spiny caterpillars can cause a mess, but they are not a threat to oak trees. Late fall leaf loss is not a problem since the trees are already headed into dormancy. Learn more about the Orangestriped Oakworm 



BECOME A CITIZEN SCIENTIST!

Where did all the cankerworms go? Help us unravel the mystery! Become a citizen scientist and collect data on cankerworms. LEARN HOW.


What is the fall cankerworm?

The fall cankerworm (Alsophila pometraria) is an insect native to North America. It is typically found from Georgia to Nova Scotia and west to Texas. It has a four-stage life cycle: egg, pupa, larva (caterpillar) and adult.

How does the fall cankerworm affect trees?

After mating in December, the female moths crawl up trees to lay their eggs on twigs and small branches. As the trees leaf out in the spring, the eggs hatch, leaving small green caterpillars to feed on the leaves. In most cases, the cankerworm will not kill the trees; however, repeated defoliation can weaken trees and make them more susceptible to other stresses, such as age, drought, other insects and disease.​ ​​​

What effect will tree banding have on the cankerworm?

Tree banding in November and December was an effective way of controlling the cankerworm.  By applying a glue barrier to the tree trunk, the wingless cankerworm moths are trapped as they climb the tree. 
 

For best results, band between the Thanksgiving and Christmas holidays. 

It is important to wait until most leaves have fallen from the trees so they don't get stuck to the tree bands. 

Why did Charlotte have a fall cankerworm problem?

For the past 30 years, the cankerworm population in Charlotte has continued to grow. Natural controls have not been adequate to bring the cankerworms to a level that isn't harmful to our tree canopy. Aerial spraying in 1992, 1998 and 2008, along with other natural factors, reduced the population for several years. The City started a banding program on street trees, while requesting homeowners and businesses to cooperate in 1990.  

The banding efforts continued for over 25 years. Entomologists cannot explain why the cankerworm populations were so high for so long, but the City's large concentration of old willow oaks may have promoted the infestation. ​

​Video: Why band your trees?

​Video: Tree-banding instructions


 
The Fiery Searcher Beetle (Calosoma scrutator) likes to feast on cankerworms and could possibly help control infestations in the future. If you see this beetle around your home, consider it a friend and ally in the fight against cankerworms.

 

 
Banding trees is an effective way to trap the cankerworms.
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