Mr. David Gordon
Katahdin Forest Products Company
PO. Box 145
Oakfield, ME 04763

Dear Mr. Gordon:

In response to your recent phone call on the insect resistance of Northern White Cedar:

The heartwood of Northern White Cedar (Tl1l4a occidentalis) is classified as resistant or very resistant against decay, and it is known to be resistant to wood boring insects as well. A 1961 Canadian government publication lists Northern White Cedar wood as being one of the most resistant against decay and insect attack. The Thuja species are generally considered to have high heartwood durability against both decay and insect attack because the heartwood extractives they produce are toxic to biological deterioration agents. A recent (2001) report in the Canadian Journal of Plant Science on the insectidal effects of extracted oils from Thuja occidentalis wood shows that the extract has significantly higher insectidal properties than other botanical insectidal oils that it was compared to, including those extracted from tropical plants.

I hope this information helps.

Sincerely yours,

Professor Barry Goodell, PhD
Wood Science and Technology
Cooperating Professor, Chemical Engineering
and the Advanced Engineered Wood Composites Center University of Maine