Mark Ware, left, and Bob Dolan, of Rainbow Ecology, demonstrated how people could deter the invasive hemlock woolly adelgid from infesting their hemlock trees at a workshop Wednesday with the Butler City Shade Tree Commission. SUBMITTED PHOTO

Pennsylvania’s state tree is the hemlock, a native species found all over the state. Since the 1950s, the hemlock woolly adelgid has been spreading throughout the state as well, but the insect is an invasive species that can kill a hemlock tree in a matter of years.

On Wednesday, the Butler City Shade Tree Commission hosted a workshop where arborists and pesticide applicators showed people how they could protect their hemlock trees from the adelgid.

Mark Ware, northeast technical adviser for Rainbow Ecoscience, said that because the adelgid is invasive, it has no natural predators and nothing to keep it from multiplying, aside from human intervention.

“The trees have had no reason to evolve and adapt to develop resistance to these pests because they have never had to deal with them before,” Ware said. “One of the treatment strategies we showed Wednesday is we put pesticides directly into the tree, so there is no pesticide exposure to the air; it goes right into the tree.”

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