Attack Density Regulation: a New Approach to the Use of Pheromones in Douglas-fir Beetle Population Management12

1978 ◽  
Vol 71 (4) ◽  
pp. 633-637 ◽  
Author(s):  
R. L. Hedden ◽  
G. B. Pitman
1979 ◽  
Vol 111 (9) ◽  
pp. 1069-1078 ◽  
Author(s):  
T.S. Sahota ◽  
A.J. Thomson

AbstractTo discover measurable parameters for detecting quality differences (with respect to reproduction) in insect populations, variations in temperature were utilized to obtain manifestation of quality at different levels. Rates of reproductive and associated processes such as yolk deposition, gallery excavation, and oviposition were measured in Dendroctonus rufipennis (Kirby) at four temperatures. Information presented here allows an estimation of D. rufipennis reproduction as affected by temperature. Among the various parameters measured the length of initial egg-free gallery and the number of eggs/unit productive gallery length and yolk deposition rate could be used to discriminate bark-beetle population quality. Rates of yolk deposition appeared most useful and widely applicable for this purpose.


1997 ◽  
Vol 12 (2) ◽  
pp. 52-54 ◽  
Author(s):  
Darrell W. Ross ◽  
Christine G. Niwa

Abstract Pheromone baits for the Douglas-fir beetle were applied alone and in combination with the antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH), to test potential treatments for creating snags to improve wildlife habitat. All baited trees were attacked by beetles following both treatments. However, more unbaited trees were attacked on plots without MCH than on plots with MCH. One year after treatment, more of the attacked trees were dead on plots without MCH than on plots with MCH. Bark beetle pheromones can be used effectively to create snags for improving wildlife habitat, but to achieve specific objectives treatments must be prescribed based on knowledge of the expected beetle population densities. West. J. Appl. For. 12(2):00-00.


1972 ◽  
Vol 2 (4) ◽  
pp. 417-426 ◽  
Author(s):  
C. B. R. Sastry ◽  
A. Kozak ◽  
R. W. Wellwood

A new approach is presented to evaluate the effects of fertilizer application on wood properties of Douglas-fir, in particular weight of tracheid and its length. A specially developed quartz ultra-microbalance was used to weigh tracheids (holocellulose and alpha cellulose skeletons), from wood formed by trees treated with four different formulations (urea, NPK, (NH4)2SO4, NH4NO3).Following the year of fertilization, tracheid weight decreased or remained static for 1 or 2 years; subsequently there was an increase in the weight of individual cells. Highly significant correlations (R2 more than 64%) were found between length of tracheid and weight of carbohydrate material in it. Variations in cell weight following fertilizations, for the most part, were associated with changes in tracheid length.Although the study was not intended as a statistical sampling for the species, the results nevertheless illustrate that qualitative differences attributable to treatment composition (urea vs. NPK vs. (NH4)2SO4) exist, in that some treatments resulted in less weight of alpha cellulose per unit length of tracheid, when compared with normal wood tracheids. This reduction in cellulose fraction was suggested as a possible factor for differences observed in gross wood specific gravity in wood of some fertilized trees.


Author(s):  
Eric K. Zenner ◽  
JeriLynn E. Peck

Structural variability in natural Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests hinders restoration targets for the full old-growth developmental sequence. To guide stage-specific restoration, we present a new approach toward developing a simple index of the vertical diversification (VD) stage. VD-associated sub-stand structures were objectively identified by quantifying the size structures of live trees across a developmental sequence of 10 pristine stands in the Oregon Cascades, USA. Floating neighborhoods were used to delineate natural tree neighborhoods based on triangulated irregular networks in five concentric rings of ever-greater spatial extent (averaging 60–2060 m2). Diameter distributions summarized the most frequently encountered tree size structures among neighborhoods, with increasing deviation from the neutral multi-variate core. Of 18 observed diameter distribution types (DDTs), the core DDT characterized all-sized tree neighborhoods reflective of vertical diversification, which was most abundant in early old-growth (VD) stands and least abundant at the extremes of the sequence. VD declined in older stands, whose more distinct DDTs had peaks in larger trees and multiple size classes, likely reflecting horizontal diversification (HD). This new approach illustrates that structural restoration of VD stands could be facilitated by the single-tree selection method, while that of HD stands may be promoted with both single-tree and group selection as well as targeted release.


1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.


Author(s):  
V. Mizuhira ◽  
Y. Futaesaku

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.


Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.


Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.


Author(s):  
Arthur V. Jones

With the introduction of field-emission sources and “immersion-type” objective lenses, the resolution obtainable with modern scanning electron microscopes is approaching that obtainable in STEM and TEM-but only with specific types of specimens. Bulk specimens still suffer from the restrictions imposed by internal scattering and the need to be conducting. Advances in coating techniques have largely overcome these problems but for a sizeable body of specimens, the restrictions imposed by coating are unacceptable.For such specimens, low voltage operation, with its low beam penetration and freedom from charging artifacts, is the method of choice.Unfortunately the technical dificulties in producing an electron beam sufficiently small and of sufficient intensity are considerably greater at low beam energies — so much so that a radical reevaluation of convential design concepts is needed.The probe diameter is usually given by


1968 ◽  
Vol 32 (3) ◽  
pp. 279-282
Author(s):  
JI Mock ◽  
JW Grenfell ◽  
WA Richter
Keyword(s):  

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