by U. S. Department of Agriculture (Author), Forest Service (Author)

The newest edition is published by the U.S. Forest Service, Northeastern Area State and Private Forestry. This edition includes a number of new pests, many of them found on fir Christmas trees. The original manual had a strong emphasis on Scotch pine. Most of the original pest descriptions remain in the manual; however, given that Christmas tree growers are growing more fir and other species, new pest problems needed to be addressed.