Christmas tree pests and weeds of different pests, most of which cause cosmetic damage to the trees, important in the Christmas tree industry. The balsam woolly adelgid ("Adelges picae") are small soft-bodied insects which attack the Fraser fir. The insects appear as white, woolly spots on the tree and are fatal to the fir if left untreated. The woolly adeligid was native to central Europe where it affected the silver fir; it was introduced to the United States, where it has no known native predators, before 1900. Balsam twig aphids ("Mindarus abietnus") are another type of tree pest which affects fir and spruce trees in
Douglas E. Noble at UC Berkeley. His dissertation focused on implementing an early computer-supported issue-based information system (IBIS), and he was a co-author on a research paper on IBIS with his dissertation chair Horst Rittel. Books: Edited Journals and Conference Proceedings: Catalog: Video: Douglas E. Noble Douglas E. Noble is an American architect and tenured faculty member at the USC School of Architecture. He is a fellow of the American Institute of Architects. He is known for his work in four overlapping arenas: Architectural Computing, Building Science, Architecture Education, and Design Theories and Methods. He received the ACSA/AIAS New Faculty Teaching Award in