SIOUX FALLS, S.D. (KELO.com) -- South Dakota has become the 33rd state to confirm that the emerald ash borer has arrived, leading to an emergency quarantine and a public information session tonight for residents in the western part of the state.
The quarantine is meant to restrict the movement of ash materials in Minnehaha County, because a common way the insect moves to new areas is when infested firewood is transported there.
John Ball, a forestry expert with the South Dakota State University Extension Office, said while the invasive insect has not been found elsewhere in the state, he expects it to reach Pierre in the next five years, and eventually Rapid City.
"We have only confirmed the infestation in the northern part of Sioux Falls, and we have looked," Ball said. "I predicted we'd find it in Sioux Falls somewhere between 2013 and 2018 so, so far, I'm guessing pretty good."
About 250 trees in Sioux Falls have the disease, and the insect already has killed 60 million ash trees nationwide since 2002.
From the 1920s through the 1980s, millions of American elm trees were decimated by Dutch elm disease, which Ball said led homeowners to over-plant ash trees, and also maples. He has some advice for homeowners who want to be proactive in planting new trees.
"Let's get off this kick of just going to the flavor of the month and planting all of one grouping: all maples or all ash or all elm," he said. "Instead, my advice to people that are planting trees now is look what your neighbors have planted, and plant something else."
One way Sioux Falls plans to slow the spread of disease to its 80,000 ash trees is by introducing parasitoid wasps that prey on the borers. Ben Slager manages the Michigan laboratory producing the wasps. He said they're not dangerous, and give trees a better chance of survival.
"They're really only interested in laying their eggs in emerald ash borer," Slager said. "They won't bother humans, they're not going to bother your pet, they're not going to go after anything other than emerald ash borer."
Scientists believe the ash borer arrived in the U.S. in the 1990s, most likely hitching a ride in wooden shipping crates from Russia, China, Japan or Korea.
(Roz Brown, GDNS, contributed this report.)