The attack spatial pattern of the Douglas-fir beetle, Dendroctonus
pseudotsugae Hopkins was shown to be regular within a given subarea
of bark on its host, Pseudotsugae menziesii (Mirb.) Franco. Empirical
arguments were advanced which indicated the uniform spacing of attacks
was the result of a beetle controlled spacing mechanism dependent...
Felled second-growth Douglas-fir trees in western Washington were used
to determine the attack distribution and develop a sampling technique
for an endemic Douglas-fir beetle, Dendroctonue peeudotaugae Hopk.
(Coleoptera: Scolytidae) population. The attack density varied by
circumferential position. The lowest density was on the upper bole
and the highest on one...
The insects that invade a dying or dead tree are the immediate cause of death and the principle mediators of early stages of decomposition of the tree. These insects form a large and complex community, the species
components of which are restricted to particular habitats. A study of
Trees in a Douglas-fir stand infested with western spruce budworm were treated with a systemic insecticide to protect cone and seed production at three locations in Montana during 1983. Treatments applied were (1) acephate as an Acecap implant, (2) acephate as an Inject-A-Cide injection, and (3) control. Potential cone-bearing trees...