Silver flies released to control hemlock woolly adelgid in Pennsylvania’s Allegheny National Forest
The U.S. Forest Service announced the release of a new biological control on the Allegheny National Forest to help combat the non-native, invasive hemlock woolly adelgid.
Hemlock woolly adelgid (Adelges tsugae) is an invasive forest insect native to Japan and the Pacific Northwest. The adelgid poses a serious threat to eastern hemlock and Carolina hemlock, which are at risk of fatal infestations since they lack natural resistance.




