The purpose of this study was to study in some detail
host factors which influence the population dynamics of
bark beetle. The dissertation objectives were to ascertain
the applicability of utilizing osmotic pressure
values and relative turgidity values of phloem tissue as
indicators which reflect upon the physiological profile
of...
Two populations of the pine needle scale, Phenacaspis pinifoliae
(Fitch), were studied. One population was located in Corvallis,
Oregon, and the other population was located near Santiam Pass,
Oregon. Both populations were feeding on Pinus contorta.
The Corvallis population was unisexual, univoltine, and over
wintered as both eggs and adult...
This study concerns factors affecting production and survival
of ascospores of Elytroderma deformans (Weir) Darker, a needle
cast of ponderosa pine (Pinus ponderosa Laws.).
The results show that summer cooling and a reduction in host
vigor delays and diminishes the number of fertile hysterothecia
produced. Evidence is offered for classification...
Pine needle blight of Pinus ponderosa Laws. caused by
Elytroderma deformans (Weir) Darker is recognized by changes in
the needles, in the bark and in the development of the branches.
Anatomical studies of the host-parasite relation have been made previously
on young pine tissue up to four years of age...
Root rot of ponderosa pine caused by Armillaria mellea was
studied in a pine forest that had been under management for 30 years
in Klickitat County, Washington. Information sources included
disease survey, detailed observation and description of specific
disease situations, and examination of roots in situ and removed.
Roughly circular...
In 1967, Lophodermella morbida Staley and Bynum, a recently described
hypodermataceous needle-cast fungus, became destructively
epidemic in a knobcone pine (Pinus attenuata Lemm.) plantation in
Del Norte County, California, and in several ponderosa pine (P.
ponderosa Laws.) plantations in western and southwestern Oregon.
This thesis presents information on this currently...
The Bureau of Entomology has been conducting systematic and economic
investigations of the weevils infesting the bark of the trunk and
terminal shoots of conifers in the United States, the results of which will be
published in the regular technical and popular bulletins ; but since these can not be...
