Imprelis(aminocyclopyrachlor), a powerful herbicide made by DuPont Professional Products, is used to kill pesky weeds but experts believe it may also be killing trees.

Imprelis was just introduced in April and it has been used by several lawn services when spraying for weeds.

A South Bend expert said that he has received several calls in the past two weeks about damaged or dying trees -- all of those callers had one thing in common.

Ralph Komasinski and his wife have lived in their South Bend home for ten years.

“It was one of the reasons we bought the house was the lot and the trees that are on the property,” said Komasinski.

One of those trees is a nearly century-old Norwegian Pine. Through the decades, it’s survived snow storms and tornadoes, and provided shade from the sun. Those days are not over, something that’s not a sign of the tree’s age.

“We've been getting several calls a day now and they started picking up about a week ago,” said certified arborist David Duncan. “All of them that have dead spruce trees and damaged other plants, the only common denominator I could find was they were all using the same herbicide .”

Duncan believes that Imprelis is killing off trees around Michiana but believes this could only be the beginning.

“One of the first sites I visited a couple weeks ago, four evergreens were damaged and yesterday I visited and I'm seeing the curling on pin oaks and pear trees and red buds and on into the deciduous trees,” said Duncan.

DuPont said it’s investigating the issue.

Meanwhile, Komasinski’s tree continues to die, he just wants to know is why.

“Why wasn't more warning given, particularly to the lawn care applicators, before this product was sprayed across the country?”

Duncan said there is one property in Bourbon, Ind. with about 100 pines, all of them have the same wilting, brown needles on them.

He says unlike deciduous trees, or trees that go dormant, pine trees cannot reproduce their needles which they’re burnt, which means those trees are a total loss.

Because the product is so new, Duncan says he’s unsure what component in Imprelis is causing the damage.