Following an Ips bark beetle outbreak in 2002, mortality of ponderosa pine (Pinus ponderosa Douglas ex C. Lawson) was evaluated in 2 study areas infested with southwestern dwarf mistletoe (Arceuthobium vaginatum [Willd.] Presl subsp. cryptopodum [Engelm.] Hawksw. & Wiens) in the Coconino and Tonto National Forests, Arizona. A pairwise comparison of dwarf mistletoe ratings for live and dead ponderosa pines was conducted to determine whether dead ponderosa pines had higher dwarf mistletoe ratings than pines that were not attacked. In both study areas, dead ponderosa pines had significantly higher dwarf mistletoe ratings, indicating an association between the severity of dwarf mistletoe infection and susceptibility to attack by Ips spp. We suggest that the probability of ponderosa pine mortality is greater in stands severely infested with southwestern dwarf mistletoe in northern Arizona.
Kenaley, Shawn C.; Mathiasen, Robert L.; and Daugherty, Carolyn M.
"Selection of dwarf mistletoe–infected ponderosa pines by Ips species (Coleoptera, Scolytidae) in northern Arizona,"
Western North American Naturalist: Vol. 66
, Article 2.
Available at: http://scholarsarchive.byu.edu/wnan/vol66/iss3/2