First Report of Golden Dwarf Mistletoe on Pinus maximinoi

Abstract

Golden dwarf mistletoe (Arceuthobium aureum subsp. aureum Hawksw. & Wiens) is endemic to east-central Guatemala (Departments Alta Verapaz, Baja Verapaz, and Quiche) (1,2). Its principal hosts are Pinus pseudostrobus Lindl., P. montezumae Lamb., and P. oaxacana Mirov (1). In May 1999, A. aureum subsp. aureum was observed infecting Pinus maximinoi H. E. Moore at four locations: 1.0 km south (altitude 1,580 m) and 5.4 km north (altitude >1,630 m) of La Cumbre, Baja Verapaz on Route CA-14, 8 km west (altitude 1,670 m) of Chilasco, Baja Verapaz, and 5 km west (altitude 1,490 m) of San Cristobal Verapaz, Alta Verapaz on Route 7-W. Although previous reports (1,2) indicated that golden dwarf mistletoe does not induce witches'-brooms on its hosts, older (>50 years), severely affected P. maximinoi were observed to have formed large witches'-brooms as a result of dwarf mistletoe infection. Although it has been suggested that Pinus oocarpa Schiede is susceptible to golden dwarf mistletoe (1), several large trees of this species were observed growing within 5 m of infected P. maximinoi at three of the four locations, but none were infected. This is the first report of golden dwarf mistletoe on P. maximinoi.