Hemlock Woolly Adelgid (HWA)
An exotic insect pest that was found infesting trees in Ohio for the first time in August, 2002.
 The first discovery involved 15 hemlock trees grown at a nursery in a state east of Ohio and purchased in Ohio as balled & burlap stock. The hemlock trees were planted in a home landscape near Painesvile (Lake County) three years prior to discovery of the insect.
Of the 15 trees planted, 8 were infested with HWA. Other hemlock trees growing in the surrounding area were inspected, but none were infested. The Ohio Department of Agriculture (ODA) destroyed the 15 trees on August 28, 2002 to ensure that the insect did not spread to other trees.
A second HWA infestation was subsequently discovered in November, 2002. This infestation involved 5 hemlock trees growing in a home landscape near Stow (Summit County).
All 5 trees harbored HWA and had been planted about 6 years prior to discovery of the insect. These trees also originated in a state east of Ohio, but were purchased here in our state. Again, surrounding trees were inspected but were not infested. ODA destroyed the 5 hemlocks on November 19, 2002.
In 2004, HWA was discovered at two additional locations in NE Ohio. Both cases involved infested landscape trees that were planted within the past 3-5 years.
The infested hemlock trees were found near Bainbridge (Geauga County) and in Hudson (Summit County). A detection survey was performed and the insect could not be found on trees away from the infested sites. On August 9, 2004, ODA destroyed the infested trees (9 trees in Summit County and 2 trees in Geauga County) in an effort to eradicate the pest from these sites.
 Additional Information
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| Infested Hemlocks were cut down and prepared for bagging. |
Hemlock branch infested with HWA. |
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| Bagged trees were transported in closed vehicles |
Infested trees were burned to destroy insects. |
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