Charlotte homeowners hoping to band trees against cankerworms this fall may be stuck in their tracks because of an international shortage of Tanglefoot.
The gooey material is used to trap the climbing pests before they can damage trees, but the production ended last February after the company that manufactured Tanglefoot went out of business. In Charlotte, supplies are limited to what retailers have available on their shelves.
If you are running low and need to buy more, arborist Patrick George emphatically recommends: “Do it now.”
George will be sharing suggestions for proper tree banding and other aspects of tree care on Nov. 19, at a meeting of Crown, the Charlotte Chapter of the North Carolina Wildlife Federation.
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Cankerworms are only one of the threats facing Charlotte’s urban forest. George worries about trees being stressed and lacking vigor because of last summer’s early heat, and newly arrived insect pests such as lecanium scales.
“The most important thing a person can do for their trees, is to be aware of changes,” George says. “That’s true even if they can’t pinpoint what it is. A big red flag for me is when someone says ‘I see something different about my tree...’ ”
Both George and the city of Charlotte recommend banding trees this year. If Tanglefoot runs out, they suggest an alternative, “Bug Barrier.” Bug Barrier, which uses plastic sheets coated with adhesive, has dropped to second choice locally, due in part to persistent problems from squirrel damage. It also is more expensive. However, experts say Bug Barrier is effective.
Cankerworms are the caterpillars of two different species of moth. Charlotte is mainly afflicted by the “fall cankerworm.” Wingless females climb trees in late autumn, triggered by cold weather and shorter days.
Once high in the treetops, they release pheromones to attract flying males for what George calls “a big party.” The females lay 100-200 eggs, which hatch in the early spring just as fresh new leaves appear.
In a bad year, the tiny “inchworms” can completely strip trees bare and rain down webs and “frass,” or droppings. They attack not only shade trees but fruit crops such as apples as well.
George said cankerworms rarely kill a tree outright, but they can weaken trees and make them more vulnerable to death from other causes. This is particularly true when the caterpillars defoliate trees for two or three years in a row.
Done properly, banding is effective and non-toxic. It works by capturing the females as they climb up the trees. However, George cautions, timing is essential. Although his company is now putting up bands, they will not coat them with Tanglefoot until around the beginning of December.
Like TV zombies, the females mindlessly pursue their climb, and will use leaves or the dead bodies of their stuck sisters as a bridge across the goo. George suggests waiting until after most leaves have fallen before applying Tanglefoot, and being ready to apply a second band if the first gets covered in bug corpses.
With the arrival of a natural predator to our area, the fiery searcher beetle, George now recommends removing bands in the early spring when trees start to leaf out, so the beetles can go up tree trunks in search of prey.
If you are not able to band this year, George said, it is not the end of the world. You can still help maintain control if you band the following year. If damage is severe in the spring, George suggests fertilizing trees to supplement nutrients.
It is also possible to spray caterpillars when they first appear, though reaching high in the treetops is challenging and expensive – the city has used helicopters in the past. The caterpillars are more vulnerable when small, especially to the safest organic control, a beneficial bacterial known as “Bt.”
George recognizes that parts of Charlotte have mature trees, over a century old in some cases, that may now be coming to the end stages of their lives. He sees this as a natural process:
“It is not unusual in nature for a big tree to go away. Think of the rain forest. It is the same thing here, on a different scale.”
Meanwhile, facing the immediate shortage, George and other experts say there is no easy do-it-yourself recipe for a Tanglefoot alternative.
Tanglefoot dates back over 125 years. The Tanglefoot Co., of Grand Rapids, Mich., started selling popular flypaper products in the horse-and-buggy days of the 1870s. Riding a wave of renewed interest in green alternatives to pesticides, it was purchased in late 2009 by Contech, a Canadian firm.
Contech went out of business early this year, after bankruptcy restructuring was blocked by a disgruntled creditor in a dispute over plastic prefab garden kits.
Fortunately, the Tanglefoot shortage should be temporary. Consumer gardening giant Scotts Miracle-Gro has purchased the Tanglefoot formula, and production is slated to resume in the spring of 2016, says Leeann Pfleider, Consumer Service Specialist for Scotts.
Don Boekelheide is a freelance writer: firstname.lastname@example.org
Want to go?
The Crown November program, “Tree Health and cankerworm Control,” with arborist Patrick George of Heartwood Tree Service, will be held 7 p.m. Nov. 19 at McClintock Middle School, 1925 Rama Road in Charlotte. Admission is free. For more information, go to www.crowncharlotte.org.