A park visitor walks across Jordan Stream in front of Cobblestone Bridge in Acadia National Park. (Photo by Will Newton/Friends of Acadia)

Like an unwanted house guest, the Hemlock woolly adelgid (pronounced [uh-del-jid]) has taken up residence near the Cobblestone Bridge on the boundary of Acadia National Park. While it might not eat all the food in the fridge, it does pose a serious risk to the region’s hemlock trees.

Hemlock woolly adelgid (HWA) has been found near the Cobblestone Bridge, on the Land and Garden Preserve’s boundary with Acadia National Park. HWA is an invasive, aphid-like insect that attacks North American hemlocks.

HWA is a specific threat to the park and its ecosystems because shade cast on streams by hemlock trees provides vital cool-water habitat for water-dwelling invertebrates. Most of the trees in view from the Cobblestone Bridge are hemlocks. If hemlocks die off, stream temperatures rise, and invertebrate populations decrease, this could cause more issues up the food chain, including for brook trout and other freshwater species.

Unfortunately, as Acadia experiences warmer winters due to climate change, it becomes easier for invasive pests like HWA to survive and flourish unchallenged.

• Read more about the recent discovery of HWA near Acadia
• Read more about the impact of climate change in Acadia