Bah Hum”bug” Of Your Holiday Decorations

It’s easy to get excited about the holiday season.  From presents and food, to holiday decor – we can take it over the top!  While a lot of that is not only enjoyable, some things we do might actually put the state’s ecosystem at risk.

Shahla Werner, Plant Protection Section Manager at the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) has been following the patterns of potential freeloading invasive insects traveling to the state via holiday decorations.  Werner says it’s happening more and more each year.  

Inspectors conducting routine checks have detected the presence of elongate hemlock scale in shipments from eastern states. This pest, not native to North America, poses a significant threat to the state’s ecology and Christmas tree growers. Originally introduced accidentally into New York around 1908, this pest has been identified as a hitchhiker on various holiday greenery.

The elongate hemlock scale, known for infesting and feeding on conifer needles, particularly targets tree species like Fraser fir, balsam fir, and others used widely for Christmas decorations.

“Preventing the spread of this pest is critical for protecting Wisconsin’s northern forests and our local Christmas tree growers,” says Werner. “We have proposed and activated a quarantine for the elongate hemlock scale to safeguard against infested material entering the state. However, public vigilance is essential.”

Identifying the elongate hemlock scale involves inspecting the undersides of tree branches where tiny fish-scale-like formations appear. Males exhibit white scales, while females display brown scales, often with visible yellow eggs underneath their hard waxy coverings. The mobile form of these insects, known as crawlers, poses the greatest threat. They can transfer to nearby coniferous trees, potentially causing an infestation.

Consumers are encouraged to buy locally sourced Christmas trees and greenery to support Wisconsin’s agricultural community and minimize the risk of introducing pests. Purchasing from local growers not only ensures high-quality products but also contributes to a sustainable environment. A list of cut-your-own and retail lots is available from the Wisconsin Christmas Tree Producers Association at

“We understand the joy of the holiday season and the tradition of selecting a perfect tree or festive decorations,” Werner added. “By choosing locally grown products, you’re not only supporting our farmers but also safeguarding Wisconsin’s natural habitat.”