Ta. Forge et Jr. Sutherland, POPULATION-DYNAMICS OF THE PINE WOOD NEMATODE, BURSAPHELENCHUS-XYLOPHILUS, IN EXCISED BRANCH SEGMENTS OF WESTERN NORTH-AMERICAN CONIFERS, Fundamental and applied nematology, 19(4), 1996, pp. 349-356
The population dynamics of two strains of the pine wood nematode, Burs
aphelenchus xylophilus, were studied in excised branch segments of Pin
us contorta, Abies grandis, Pseudotsuga menziesii, Tsuga heterophylla
and Thuja plicata inoculated with the blue-stain fungus, Ophiostoma pi
ceae. Nematodes were inoculated into small holes drilled into the cent
er of the branch segments. Size and age-structure of the nematode popu
lations were determined at regular intervals after inoculation. Nemato
de population growth occurred in branch segments of all tree species t
ested. However, population densities were significantly greater in P.
contorta than in the other species. In one experiment, respective popu
lation densities in branch segments of P. contorta, A. grandis, P. men
ziesii T. heterophylla and T. plicata increased from 2, 0.02, 0.1, 0.0
4 and 0.05 nematodes/g dry wood at 2 weeks after inoculation to 57, 15
, 11, 13 and 6 nematodes/g dry wood after 16 weeks. The relative abund
ance of persistent third-stage juveniles (J3P) increased through time
in all tree species and was greatest in P. contorta at most sample dat
es. The relative abundance of J3P was significantly greater in P. cont
orta than in the other species in one of two experiments only.