Hemlock Wooly Adelgid

Hemlock wooly adelgid is a persistent pest of hemlocks. It is an imported pest from asia and thrives here because it has no natural predators to keep populations in check. The white cottony sacs are actually females surrounded by 100 – 300 eggs. Eggs hatch into a "crawler" stage. Crawlers move out and settle on other unoccupied parts of the tree. It is at this stage that adelgids catch rides on birds, wind and other creatures spreading to other hemlocks.

We can easily rid your trees of hemlock wooly adelgid with 3 seasonal sprays of horticultural oil or with systemic imidicloprid.

When treating with horticultural oil it is important to get thorough coverage, spraying from underneath. I have been dealing with this pest for 20 years and have had great success with 3 treatments with a 2% horticultural oil the first in the spring before the new growth comes out, again in july when the new growth has hardened, and again in the fall around October.

Treatments with imidicloprid last for the entire season. Treating in the fall is the ideal timing for first time applications. Subsequent applications (one per year) can be performed any time.

Many times we do such a nice job of cleaning up an infestation that a client stops service because they feel they don’t need it. It usually takes two years and they call us back because their hemlocks are reinfested.