States trying to stop invasive evergreen-eating bug's spread

MILWAUKEE — Wisconsin and Minnesota agriculture officials are trying to block the spread of an invasive evergreen tree-eating insect after it was found in holiday decorations sold at retailers in both states.

Wisconsin inspectors found the critter called elongate hemlock scale on decorations including wreaths and evergreen boughs sold at Menards, Home Depot and other stores, Minnesota Public Radio News reported. It wasn't found on Christmas trees.

After consulting with Wisconsin, inspectors in Minnesota on Thursday found the insect on decorations at Menards and Home Depot stores in the Twin Cities region. The infested materials came from North Carolina suppliers.

Officials are worried the bug could escape and infest forests and neighborhoods if evergreen decorations are composted, put out for collection or left in the woods. Officials suggest burning evergreen decorations or bagging them for the landfill.

The insect doesn't kill trees outright, but saps nutrients and weakens them — leaving them vulnerable to other diseases and pests. The bug, also known as EHS, eats the undersides of needles of over 40 conifer tree species.

It has spread to 16 states after being introduced to the U.S. from Asia.

"EHS has survived in the northeastern U.S., so winter weather will not kill it," said Brian Kuhn, director of the Plant Industry Bureau in the Wisconsin Department of Agriculture, Trade and Consumer Protection. "As a result, if you compost this material, the insects may well attack conifers in your yard or neighborhood and spread from there."

Wisconsin inspectors have discovered isolated cases of the bug at Christmas tree lots and other tree and wreath sellers in the past five years.

"This year, because we found it at so many different outlets, we really were very concerned that it could get out into the environment and become established here if we didn't move quickly," said Donna Gilson, a spokeswoman for the Wisconsin Department of Agriculture, Trade and Consumer Protection.

Minnesota Agriculture Department officials are looking into where the infested evergreen materials may have been sold outside of the Twin Cities area.