Webworms invade Wilton

Susan Shultz video
Late last month, Wilton resident Jean Tompkins found a webby nest in a weigela shrub at her Skunk Lane home. After informing neighbors about her discovery, Tompkins said, a few of them reported finding similar nests in their trees as well. These nests belong to webworms.

Webworms, also known as “fall webworms,” are native North American insects that spin sticky webs on plants in their caterpillar stage.

In northern North America, webworm caterpillars tend to have hairy yellow bodies with black dots and black heads. In their moth form, webworms can be white or white with brown patches, and have hairy thoraxes and legs that are either white or orange with brown.

After hatching, webworm caterpillars “immediately begin eating and building a tent web” on twigs, branches and trees to protect themselves from predators as they feed on the leaves of the host plant,” according to insectidentification.org.

One to four generations of webworms can be produced each year, and the insects are most active in the fall — consuming leaves before foliage dries up and fall off. They feed on a large variety of leaves, including those of hickory, alder, elm, willow, mulberry, oak, popular, sweetgum, birch, cherry, apple and pecan trees.

On Aug. 27, the Wilton Garden Club posted on Facebook about the “alarming infestation” of webworms on Skunk Lane and advised residents to be “on the lookout for these super destructive pests.”

The infestation, however, is not restricted to Skunk Lane. A Wilton resident found a webworm nest on a hydrangea on her Briardale Place property, and a Cherry Lane resident found one on her apple tree. A nest was also found on Pimpewaug Road.

According to the garden club, webworms can “destroy a large tree in a single season if they’re not controlled.”

“If you catch them early, you can simply cut off and burn the infested branches,” according to the club. Burning branches, however, require a burning permit from the Wilton Fire Department.

Tompkins said she cut off the infested branches on her property and threw them away, but one of her neighbors did obtain a burn permit.

“The fireman who came on the property said he’s been seeing a lot of these nests,” said Tompkins.

If a webworm problem has “gotten out of control,” according to the Wilton Garden Club, “it’s best to bring in an arborist to deal with it.”

While light infestations of webworms can be controlled by “pruning the nests and destroying them,” according to the Connecticut Agricultural Experiment Station (CAES), larger infestations can be controlled with foliar sprays of carbaryl or phosmet. Carbaryl and phosmet are “among the compounds registered for use against this pest in Connecticut,” according to the CAES.