Hemlock Woolly Adelgid

Research Questions: Where is hemlock woolly adelgid now, and where might it spread next? Is climate change affecting how hemlock woolly adelgid spreads?

Why this matters

Hemlock woolly adelgid is devastating eastern hemlock populations across the Gulf of Maine watershed. We need more data to figure out where it is now so we can prevent it from spreading further.

  • Maine Forest Service

Any Time of the Year

Hemlock Woolly Adelgid

Protocol Overview

  1. Select a field site with eastern hemlock trees.
  2. Identify a hemlock tree to examine closely. Mark your tree with flagging tape so others will not survey the same tree.
  3. Take pictures to show that the tree is an eastern hemlock.
  4. Search 10 branches that are at least 1 meter long for hemlock woolly adelgid.
  5. Record whether you found or did not find hemlock woolly adelgid and take photos of evidence of hemlock woolly adelgid.
  6. Scan the needles for hemlock elongate scale. If you think you find it, write "Elongate scale present" in the Field Notes section.


Project Owners


Gary Fish

Maine Forest Service

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Colleen Teerling

Maine Forest Service

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Project Partners

Maine Forest Service