Pinewood Nematode, Bursaphelenchus xylophilus, Associated with Red Pine, Pinus resinosa, in Western Maryland
Harman, A.L.; Krusberg, L.R.; Nickle, W.R.
Journal of Nematology 18(4): 575-580
1986
ISSN/ISBN: 0022-300X PMID: 19294229 Document Number: 281532
Red pines Pinus resinosa in Garrett and Allegany counties, Maryland, were examined during 1982-84 to determine distribution of the pinewood nematode, Bursaphelenchus xylophilus, within and among trees. Approximately 25-year-old (younger) and 47-year-old (older) trees were subdivided into the following categories: 1) trees with mostly green needles; 2) trees with mostly reddish-brown needles; 3) trees lacking needles but with bark intact; 4) trees lacking both needles and bark; 68% of younger red pines and 77% of older red pines. Nematodes were not evenly distributed in trees within any given tree decades category or in the trees of the same age. Nematodes distributed in trees within any given tree decadence category or in trees of the same age. Nematodes were recovered from 20% of wood samples from trunks and primary and secondary branches in younger pines and from 15% of older red pines. On the basis of tree decadence category, the highest incidence of infection in younger trees (31%) was in bleached-green needled trees (category 5), whereas in older trees the highest infection (25%) occurred in green needled trees (category 1). At both sites trunks were infected more often than branches.