A new insect pest known as the elongate hemlock scale is appearing in Christmas greenery sold in South Dakota and surrounding states.
“The insect was detected by our forest health team last Christmas in wreaths,” said Greg Josten, South Dakota State Forester. “The scales were found on wreaths made of fir that were shipped in from the southern U.S.”
The insect has appeared on similar material this year. “Our inspectors were alerted that this might be the case and found infested wreaths last week,” says Brenda Sievers, South Dakota Department of Agriculture. The Department has put a stop order on the sale of this material.
The Asian insect made its way to New York and then the southeastern U.S. where it has infested fir trees sheared to make wreaths. The insect will infest hemlock, fir, and spruce trees and stays alive by sucking the sap from the foliage and causes the foliage to become discolored and drop. The insect is an immobile scale, about 2 mm long, that appears as yellow-brown, parallel-sided spots on the underside of needles. It has not been found on Christmas trees in South Dakota.
Wreath material does not have to be destroyed until after the Holidays. Any fir wreaths bought from out-of-state sources should not be discarded in a brush pile or compost bin as eggs will be hatching from the scales this spring and could move to nearby spruce trees. Instead, wreaths should be disposed through any city or community Christmas tree and greenery program or the material can also be burned.
