Invasive insect threatening hemlock trees near Skaneateles Lake

Jun 30, 2014

There’s a new invasive insect causing problems in Onondaga County. The hemlock woolly adelgid has started feeding on hemlock trees in the watershed that provides water for the city of Syracuse.

An alert arborist found the bug that’s been on the eastern seaboard since the 1950s, munching on hemlock needles in trees on the Onondaga County side of Skaneateles Lake.

Kristina Ferrare of the Cornell Cooperative Extension office in Syracuse says the aphid-like bug gets its nutrients from hemlock needles. That interferes with the tree's nutrition and can starve it to death in as little as ten years.

She says it’s an important tree to have in the hills that lead down to Skaneateles Lake, because it provides shade, shelter and food for other species. And perhaps most importantly, its role in preventing erosion.

"They inhabit steep slopes and sensitive areas, and they are really important to preventing soil from getting into the lake," said Ferrare. "And because it’s an important drinking water source, we don’t want to see that happen.”

Officials will hold a public meeting Monday evening in Spafford to offer property owners suggestions on how to deal with the invasive bug.

“Things like don’t hang a bird feeder in a Hemlock tree which will attract birds which are a vector of spreading the disease," said Ferrare. "If you have one tree in your stand that is infested, you might consider removing that tree, to prevent your other hemlocks from getting infested and slowing the spread."

Another option is to use pesticides to kill the bugs. Ferrare said pesticides should be handled carefully, considering the lake is a drinking water source for parts of central New York.  

“There are different delivery systems and an injection system similar to the way we’ve been injecting ash trees to protect them against Emerald Ash Borer," said Ferrare. "A similar type of trunk injection is available to protect the control hemlock wooly adelgid. That keeps all the pesticide in the tree and it does not get into groundwater,” she said.

Monday's public meeting will take place at the Spafford Town Hall at 6:00 p.m.