CHARLOTTE, N.C. — It’s almost that time of year for spring cankerworms to appear. However, we could see fewer of the insects this year.
There are two theories on why the cankerworm population is trending down.
- The weather, such as a cold snap, could have an impact.
- Preventative measures like wrapping trees with sticky material could have an impact.
Once upon a time, thousands of the tiny green insects took over the tree canopy in Charlotte.
"When they are up in the tree, they drop down these little spindles of silk and they get stuck in your hair and clothes when we have really high population," Laurie Reid said. "It was just a nightmare."
City Arborist Laurie Reid said the worm population has not fully recovered from a previous spring frost and ongoing tree banding efforts.
“Back in 2017, we had five nights of below-freezing temperatures when the caterpillars were first hatching out of their eggs," Reid said. "It kind of adds up that what we saw was after those five nights are population decreased and kept going on the down low."
Reid says the insect loves a very popular tree in Charlotte: willow oaks.
“And those caterpillars can eat every single leaf off that tree, and the tree has to tap into its stored sugars to put brand new leaves on for the whole entire summer," Reid said. "So, over years and years of being defoliated, the tree has to go its bank of sugars and it can cause a decline and health of the tree."
The city has a plan to control the native cankerworm population: Wrapping select trees with a sticky, plastic wrap stops the female cankerworm in its tracks.
A good rule of thumb is to start banding in late fall and remove the bands by mid-April.
Contact KJ Jacobs at kjacobs3@wcnc.com and follow him on Facebook, Twitter and Instagram.