First report of Arceuthobium americanum on Abies lasiocarpa
Arceuthobium americanum (EPPO A1 quarantine pest) was observed for the first time on subalpine firs (Abies lasiocarpa) which were growing near heavily infected lodgepole pines (Pinus contorta), in Washington State (USA). Infected branches were usually distinctly swollen, formed dense witches' brooms, and produced few or no mistletoe shoots. Mistletoe shoots produced on subalpine fir are similar to those produced on lodgepole pine. This is the first report of A. americanum on Abies lasiocarpa which should however be considered as a rare host.
Sources
Mathiasen, R.L.; Beatty, J.S.; Hildebrand, D.M. (1996) First report of lodgepole pine dwarf mistletoe on subalpine fir.
Plant Disease, 80(3), p 342.