By LEE HINNANT

A federal scientist based in Columbus County has organized a regional network to detect and track a new pest that decimates native cactus plants and could pose serious threats if it were to spread to the West.

The South American cactus moth first appeared in this country at Big Pine Key, Fla., in 1989, said Randy Westbrooks, a plant scientist for the U.S. Geological Survey. Traditionally limited to areas south of the Amazon River basin, the moth was imported to Nevis and St. Thomas islands four generations ago to eliminate cactus plants in cattle pastures. Scientists believe that hurricanes might have blown the moth to the Keys.

The cactus moth has no natural enemies in the United States and has made its way as far north as Folly Beach, S.C., near Charleston. The moths fly in hoards and lay thousands of eggs on cactus plants. When the larvae hatch, they eat away the inside of the cactus leaves, then mature into flying moths and move on. If the larvae don’t kill the cactus outright, the plant dies from secondary mildew and mold infestations.

It takes many years for some ornamental and native cactus plants to reach a respectable size. The cactus moth will destroy these plants in only three months.

The moth eats only “flat-pad” cactuses, not the barrel-shaped varieties common to the Southwest. There are, however, 63 U.S. cactus species at risk, Westbrooks said.

The loss of native and ornamental cactuses in the South would be unfortunate but might not have dramatic environmental consequences, Westbrooks said. Should the moth spread to the West, Southwest or Mexico, however, the situation would be dire, he said.

Cactus is an important agricultural crop in Mexico, where it is grown for cattle feed and for the leaves and fruits that people eat, Westbrooks said. In the American Southwest, cactuses are a keystone species for entire natural habitats.

“If we don’t find a way to stop it, it could cause an ecosystem collapse,” Westbrooks said. “It’s not a big story yet, but it’s going to be a big story.”

Westbrooks has helped set up a network of monitoring sites in the South where volunteers are keeping watch for the moth. The network includes 41 sites in North Carolina, including Lake Waccamaw State Park and Whiteville. So far, the moth has not been detected in inland areas.

The U.S. Department of Agriculture is asking gardeners, homeowners and residents to be on the lookout for the moth. Because there is no known pesticide to kill the pest, the government effort is focused on finding the cactus moth and tracking its spread.

The most reliable way to spot the moth is to look for its larvae, which are unlike any other species found on the East Coast. Cactus moth larvae are reddish-orange with black spots that form transverse bands across the body. The larvae – also called caterpillars – are about one-half inch long and the black bands break up into spots near the tail.

Other signs of the moth are oozing, brownish splotches on the pads of cactus plants.

Anyone who spots a cactus moth larvae on a cactus plant is asked to contact Westbrooks at (910) 648-6762.

Efforts to control the moth include studies on whether the adult moths could be sterilized and released into the wild, reducing the chance for successful breeding.

For more information on the pest, point your browser to aphis.usda.gov/ppq/ Using the drag-down menu, access the pages called “emerging pests.”