USDA lays traps for leaf-devouring invasive moths found in North Charleston

Asian gypsy moths can lay waste to plants and shrubs. Officials are on the lookout after discovering two of these moths in North Charleston in the past two years.

Authorities are hot on the trail of an invasive species of moth that could lay waste to the Lowcountry’s majestic live oaks and other trees if left unchecked.

The Asian gypsy moth lays fuzz-covered clusters of eggs in the winter on more than 600 species of trees and shrubs, including oaks, poplars and some evergreens. Hundreds of caterpillars hatch in the spring and start devouring foliage around them, often stripping branches bare and leaving trees vulnerable to infections or other pests.

The U.S. Department of Agriculture found a single Asian gypsy moth in North Charleston in June 2014, and another in June 2015. The first was near Rivers Avenue and Piggly Wiggly Drive, the second on S.C. Ports Authority property near the Hanahan border. The USDA’s policy is to conduct three years of surveys following each moth discovery.

This summer marks the agency’s second intensive survey in the area, with 1,645 coated cardboard traps installed from Mount Pleasant to Charleston to Goose Creek. The triangular glue traps, which are often attached to utility poles, contain a slow-release pheromone that attracts the moths.

“It’s hard to say where it came from — maybe a ship, maybe a container,” said Marjorie Bestwick, a plant health safeguarding specialist for the USDA in South Carolina. “So far, we’re knocking on wood, we haven’t found any this year.”

Asian gypsy moths are considered a greater threat than the more common European gypsy moths, which defoliate about 700,000 acres per year in the United States. Unlike their European counterparts, female Asian gypsy moths are capable of flight and have been known to travel 25 miles at a stretch.

Bestwick said a large-scale infestation could present a serious threat to South Carolina’s forestry and tourism industries. If researchers find more specimens, she said, one option would be to spray trees with a naturally occurring bacterium that is toxic to the moths in their caterpillar stage. She said the USDA would coordinate with county authorities and hold public meetings before taking any action.

North Charleston isn’t the only place where Asian gypsy moths have reared their furry heads recently. They have also been found in Washington, Oregon, Oklahoma and Georgia. After identifying a single male specimen near the Port of Savannah in 2015, the Georgia Forestry Commission placed 900 traps in Chatham County earlier this year, according to the Savannah Morning News.

Reach Paul Bowers at (843) 937-5546 or twitter.com/paul_bowers.