AGENCY INFORMATION

• What to Look For
• More HWA Images
• Look Alikes
• Integrated Management Approach
• 2007 Situation

Hemlock Woolly Adelgid Overview

What is Hemlock Woolly Adelgid?

Hemlock Woolly Adelgid (Uh-dell-jid) (HWA) is an introduced, aphid-like insect from Asia that kills eastern hemlock.  As of 2007, sixteen states from Maine to Georgia have HWA.  Areas infested with HWA display extensive tree decline and mortality.  HWA affects all species of hemlock, but does not affect pine, spruce, fir or other conifers. 

The most obvious sign of HWA is the covering of wool-like wax filaments produced as the insect matures.  The woolly masses range from about 1/16-inch to 1/8-inch in diameter.  They are most visible from late fall to early summer on the undersides of the outermost branch tips of hemlock trees

 

---

Look for These Signs on Hemlocks:

• White woolly masses at the base of needles on undersides of hemlock twigs
• Off-color needles, often with a grayish cast
• Premature needle drop and twig dieback

Note: In Maine this insect does not damage species other than hemlocks.

 

 

If you think you have seen a hemlock tree with adelgid, note its location and
call the Maine Forest Service at (207) 287-2431 or
Toll Free (in Maine) 1-800-367-0223
e-mail: allison.m.kanoti@maine.gov

As of 2008 hemlock woolly adelgid has been found in forests of: Eliot, Kennebunkport, Kittery, South Berwick, Saco, Wells and York. Many of these detections were reported by informed citizens.

---

Don't be Fooled by These Imposters--They are not hemlock woolly adelgid

Many things look like hemlock woolly adelgid at first glance. On closer inspection, they can be ruled out either because of their texture, their location or another characteristic. Remember, HWA will usually be found on the undersides of twigs at the bases of needles and is coated with a waxy material. When in doubt, contact us.

Back to top

---

Maine’s Slow-The-Spread program for Hemlock Woolly Adelgid

Management Tools: Quarantine, Surveys and Monitoring, Chemical Control, Biological Control, Outreach

Quarantine External (between states) and internal (within Maine) quarantines regulate movement of hemlock materials to reduce unintentional movement of HWA.

Surveys & Monitoring Maine Forest Service personnel regularly survey to locate new infestations and monitor the spread of HWA.

Chemical Control In the spring and summer HWA can drop onto humans and vehicles and may be moved into uninfested areas.  Spraying infested trees in high-traffic areas, such as roadsides and residential sites, can reduce accidental human spread of HWA.

Biological Control Two species of beetle, which feed exclusively on adelgid, have been released, and ongoing research is being carried out.  Biological control is the best hope for long-term control of HWA in Maine’s forests. (Off-site: biological control of hemlock woolly adelgid)

Public Outreach An informed public plays an important role in detecting HWA.  Programs such as “Take a Stand” enlist public support and educate volunteers in HWA detection.

Back to top

---

The Maine HWA Situation in 2007

• Hemlock Woolly Adelgid (HWA) was first detected in Maine on nursery stock brought in from infested states in 1999.  
• It was found on native hemlock in 2003.
• As of 2007, HWA is established in five southern townships in York county:
       Kittery, Eliot, York, South Berwick, and Wells.
• As of August 2007, these five townships, as well as Ogunquit, are under quarantine.

 

Towns quarantined for hemlock woolly adelgid in Maine as of 2007 include: Eliot, Kittery, Ogunquit, South Berwick, Wells and York (left)

Counties in the Northeastern United states under quarantine for hemlock woolly adelgid (right) shaded in brown and yellow. Click on image for a US Forest Service pdf file.

 

 

 

 

Back to top

Maine.gov | Department Home | Agency Home | Site Policies