Invasive bug located on hemlock tree in Washtenaw County

(CBS DETROIT) – After seven counties report detections in west and northwest Michigan, an invasive insect is found in Washtenaw County.

Hemlock Woolly Adelgid (HWA) is a small aphid-like bug that feeds on hemlock trees, a type of pine. Hemlocks are not native to Washtenaw County.

HWA essentially leeches the branches of the tree, killing it.

“I’m not aware of anyone being allergic to the insect. They don’t sting, they don’t bite, they just sit there on hemlock trees and suck the life out of them,” says Mike Philip, the director of pesticide and plant pest management for the Michigan Department of Agriculture and Rural Development.

Philip says he isn’t sure where the tree came from. He says most often when HWA is detected, it’s on trees that came from outside of the state and are transferred in for landscaping.

“I mean that literally, they will spend most of their lives stuck in the tree in one place and cannot move,” Philip said.

Philip says HWA does not pose a significant threat to Washtenaw County. If you suspect HWA may be on any of your trees, you can contact MDARD here.