The Spruce Spider Mite In Fraser Fir
If you have Fraser fir Christmas trees with off-color or chlorotic foliage, especially after a dry spell in the summer or fall, chances are you have damage from the spruce spider mite (Oligonychus ununguis) (SSM).
The link address is: http://www.ces.ncsu.edu/nreos/forest/xmas/ctn_029.html