Pine disease moving west in Kansas

? A disease that has killed thousands of pine trees in eastern Kansas is migrating west and beginning to take hold in central parts of the state, plant experts say.

Pine wilt has primarily afflicted Scots pines, often used as Christmas trees, but the disease could potentially hurt any type of pine tree, said plant pathologist Megan Kennelly, an assistant professor at Kansas State University.

So far, the disease has killed thousands of trees in eastern sections of the state, she said. Officials urge land owners to combat the disease’s spread by cutting down afflicted trees and leaving no stumps, and burning the wood.

The disease causes trees to wilt and die over a period of several weeks to a few months. New pine wilt infections are most visible in Kansas from August to December, Kennelly told The Topeka Capital-Journal.

Pine wilt is caused by microscopic pinewood worms, or nematodes, that fill up the water pores of the trees. The parasitic nematodes are carried between trees by the yellow-and-black pine sawyer beetle.

The disease was first discovered in the U.S. in 1979 in Columbia, Mo., but authorities confirmed it later that year in southeast Kansas. Pine wilt has since spread west at a rate of about 10 miles per year.

Lindy Gallaher, who runs a Christmas tree farm in Manhattan, about 60 miles west of Topeka, said pine wilt has killed about 40 or 50 of his Scots pines, also known as Scotch pines, over the past five or six years. He has since stopped planting new trees.

“Eventually it’s going to wipe out just about all the Scotch pines, which was once the No. 1 selling Christmas tree,” Gallaher said. “It’s hard to imagine an entire species of trees over a period of years almost becoming extinct.”