Sclereids are sclerenchyma cells having thick lignified
secondary walls. Douglas-fir sclereids, also called bast fibers,
are long (1 mm in length), sharply pointed, spindle-shaped fibers
of a red-brown color. Sclereids from Douglas-fir bark and nine
other western coniferous species were examined for their morphology.
The external surface characteristics of sclereids...
The inner bark of Douglas-fir was successively extracted with ethanol-water (4:1 v/v), benzene-ethanol (2:1, v./iv), water, and 0.5% aqueous ammonium oxalate solution. The residue was reacted with acidified sodium chlorite, a commonly used reagent to separate lignin from carbohydrates. In general the reaction dissolves the lignin and leaves the carbohydrates...
The study (1) describes the life cycle of P. nebulosus,
(2) examines stimuli that may cause the beetles to locate brood
material, and (3) establishes the relationship between moisture
stress in Douglas-fir and colonization by P. nebuZosus.and other
meristem insects.
(1) Development of P. nebulosus goes through the egg stage,...
Both Leperisinus oregonus and L. californicus are bark beetle
species which emerge from Fraxinus latifolia brood logs as sexually
immature adults and disperse to living ash. Occasional field observations suggest that, for overwintering and maturation feeding, L.
oregonus enter trunks and branches, whereas L.; californicus enter twig
crotches, buds and...
The host preferences and wood channelization rates of
scolytid and cerambycid beetles were studied at the H. J.
Andrews Experimental Forest (Lane County, Oregon) during
1986 and 1987. Attack density and gallery volumes were
measured in fall-felled experimental logs of four major
conifer species: Douglas-fir (Pseudotsuga mensiesii (Mirb.)
Franco), western...