ON THE OCCURRENCE AND BIOLOGY OF NEPYTIA FREEMANI (LEPIDOPTERA: GEOMETRIDAE) IN UTAH

1971 ◽  
Vol 103 (1) ◽  
pp. 119-124 ◽  
Author(s):  
William H. Klein ◽  
Maxine W. Minnoch
Keyword(s):  
Life Cycle ◽  
Population Decline ◽  
Douglas Fir ◽  
Ground Vegetation ◽  
North Central ◽  
Permanent Damage ◽  
White Fir ◽  
Overall Effectiveness

AbstractNepytia freemani Munroe reached outbreak proportions in one area in north central Utah in 1965 and subsided in early 1967. The looper has a 1-year life cycle and overwinters in the egg stage. Larvae issue from eggs in mid-May, feed during the summer months, and begin pupation in late July. Adults appear in August and females lay clusters of small oval eggs on both sides of the needle. White fir is the preferred host but Douglas-fir is also fed on. Even though defoliation was extremely heavy, topkill was the only permanent damage. Starved larvae fed on ground vegetation in the understory. Parasitism was heavy but its overall effectiveness in causing the sudden population decline is unknown.

ESTIMATION OF GROWTH – TIME TEMPERATURE CHARACTERISTICS FOR ISOLATES OF FOMES PINI, A HEART ROT FUNGUS

1964 ◽  
Vol 42 (12) ◽  
pp. 1635-1652 ◽  
Author(s):  
Lee A. Paine ◽  
Gideon Schwarzbart ◽  
William G. O'Regan
Keyword(s):  
Regression Analysis ◽  
Cross Section ◽  
Growth Pattern ◽  
Storage Temperature ◽  
Three Dimensional ◽  
Douglas Fir ◽  
Growth Time ◽  
Optimum Temperature ◽  
Analysis Techniques ◽  
White Fir

Regression analysis techniques were applied to an estimation of three-dimensional surfaces representing the growth of Fomes pini as a function of time and temperature. These methods were judged to be valuable in their economy of data and in their provision of readily available plotting points for any desired cross section of the surface.The growth pattern of F. pini taken from Douglas fir was distinct from that of the form of F. pini found on nearby white fir. Growth of isolates from Douglas fir was more than twice that of white fir isolates after 18 days at near-optimum temperatures on malt agar. Estimates of growth trends and optimum temperatures were examined both for individual isolates of F. pini and for averages of isolates from the two host species, Douglas fir and white fir. Results suggest that chronological changes in the optimum temperature may be affected by the relation between the storage temperature preceding initial measurements and the terminal optimum temperature.

INFLUENCE OF FOLIAR NITROGEN LEVELS ON SURVIVAL, DEVELOPMENT, AND REPRODUCTION OF WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALS (LEPIDOPTERA: TORTRICIDAE)

1985 ◽  
Vol 117 (1) ◽  
pp. 23-32 ◽  
Author(s):  
J. Wayne Brewer ◽  
John L. Capinera ◽  
Robert E. Deshon ◽  
Mary L. Walmsley
Keyword(s):  
Larval Mortality ◽  
Spruce Budworm ◽  
Dry Weight ◽  
Douglas Fir ◽  
Nitrogen Level ◽  
Pupal Weight ◽  
Western Spruce Budworm ◽  
Foliar Nitrogen ◽  
Nitrogen Levels ◽  
White Fir

AbstractThe influence of nitrogen levels in foliage of white-fir, Abies concolor, and Douglas-fir, Pseudotsuga menziesii, seedlings on various biological characteristics of the western spruce budworm, Choristoneura occidentalis Freeman, was studied. Seedlings were grown under greenhouse conditions and provided with nutrient solutions to maintain five foliar nitrogen levels ranging from 1.29 to 4.42% dry weight for white fir and 1.43 to 3.94% for Douglas fir. Larvae confined to treated seedlings were monitored through the next generation. Larval mortality was higher, and development time longer, at both upper and lower extremes of foliar nitrogen than at mid-level. Mean pupal weight was significantly greater for larvae reared on white fir with the mid-range foliar-nitrogen level. Mean number, and weight, of eggs laid were highest when larvae fed on foliage from the mid-range nitrogen level. Total number of larvae produced was lowest at the high and low extremes of foliar nitrogen levels.

scholarly journals The rise and fall of Anopheles arabiensis (Diptera: Culicidae) in a Tanzanian village

1995 ◽  
Vol 85 (1) ◽  
pp. 37-44 ◽  
Author(s):  
J.D. Charlwood ◽  
J. Kihonda ◽  
S. Sama ◽  
P.F. Billingsley ◽  
H. Hadji ◽  
...  
Keyword(s):  
Life Cycle ◽  
Survival Rate ◽  
Anopheles Arabiensis ◽  
Light Trapping ◽  
Population Decline ◽  
Malaria Vectors ◽  
General Applicability ◽  
Dry Spell ◽  
The Village

AbstractThe continual recruitment of new individuals makes it difficult to study both the survival of multivoltine mosquitoes, and the size of the infectious reservoir in narural populations of malaria vectors. During long-term surveillance of a population of Anopheles gambiae Giles sensu lato in a Tanzanian village by daily light trapping, a temporary dry spell resulted in the cessation of recruitment for a period of 33 days, and a decline in numbers of A. arabiensis Patton caught from over 2000 to less than 10 in a sentinel house. Traps placed elsewhere in the village indicated similar proportionate declines although numbers caught varied according to location. A survival rate of 83% per day was estimated from the rate of population decline. Survival was unrelated to the size of the mosquitoes. The infectious reservoir (the chance of a mosquito acquiring an infection) was estimated to be 2% per feed. The exploitation of fortuitous events which temporarily eliminate a single stage in the life cycle has general applicability in the study of the bionomics of multivoltine insects.

scholarly journals Notched-beam creep of Douglas fir and white fir in outdoor conditions: Experimental study

2019 ◽  
Vol 196 ◽  
pp. 659-671 ◽  
Author(s):  
Claude Feldman Pambou Nziengui ◽  
Rostand Moutou Pitti ◽  
Eric Fournely ◽  
Joseph Gril ◽  
Gaël Godi ◽  
...  
Keyword(s):  
Experimental Study ◽  
Douglas Fir ◽  
White Fir

Mycorrhizae of Abies concolor in California

1977 ◽  
Vol 55 (10) ◽  
pp. 1345-1350 ◽  
Author(s):  
Isabel F. Alvarez ◽  
Fields W. Cobb Jr.
Keyword(s):  
Sierra Nevada ◽  
Mycorrhizal Fungi ◽  
Abies Concolor ◽  
North Central ◽  
Chemical Reagents ◽  
The North ◽  
Naturally Occurring ◽  
White Fir ◽  
Different Types ◽  
Cenococcum Graniforme

Nine different types of mycorrhizae were observed on naturally occurring white fir seedlings in the north central Sierra Nevada, including one formed by the ubiquitous Cenococcum graniforme. The macro- and micro-scopic characteristics and reactions to different chemical reagents are described for five types. Possible mycorrhizal fungi of white fir are listed. Nursery-grown seedlings examined were ectomycorrhizal; intracellular penetration was not observed. None of the naturally occurring mycorrhizal types were found on nursery seedlings.

On the Flight and Host Selection of the Douglas-fir Beetle, Dendroctonus pseudotsugae Hopk. (Coleoptera: Scolytidae)

1962 ◽  
Vol 94 (12) ◽  
pp. 1309-1325 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins
Keyword(s):  
Experimental Data ◽  
Life Cycle ◽  
Host Selection ◽  
Bark Beetles ◽  
Time Of Flight ◽  
Field Studies ◽  
Douglas Fir ◽  
Major Portion ◽  
Dendroctonus Pseudotsugae ◽  
Selection Of

The flight of bark beetles covers a short but important period of their life cycle, during which they are exposed to conditions not encountered during the major portion of their life under the bark. The time of flight and the factors which affect it are important, not only to the dispersal and survival of the insect, but also in the interpretation of experimental data dependent upon the beetle's flight activity.Chapman (1954), Rudinsky and Vité (1956), and Atkins (1959, 1960, 1961) studied the flight of the Douglas-fir beetle under laboratory conditions, but there is scant reference to field studies on the flight of this insect. Chapman and Kinghorn (1958) recorded the number caught in window flight traps near Cowichan Lake, B.C., and unpublished reports describe emergence records obtained from cage studies conducted near Lumby, B.C.

Douglas-fir – spruce for the 22nd century? Review of the recent Czech literature

2015 ◽  
Vol 5 (4) ◽  
pp. 51-58
Author(s):  
Подразски ◽  
Vilem Podrazski ◽  
Матвеев ◽  
Sergey Matveev
Keyword(s):  
Norway Spruce ◽  
Tree Species ◽  
Douglas Fir ◽  
Point Of View ◽  
Ground Vegetation ◽  
Negative Effects ◽  
Vegetation Diversity ◽  
Suitable Alternative ◽  
Middle Europe ◽  
The Stability

Presented paper summarizes the knowledge concerning the cultivation of Douglas-fir (Pseudotsuga menziesii /Mirb./ Franco), its production as well as its non-production forest functions in the conditions of the Czech Republic/Middle Europe. It analyzes the research outcomes from the point of view of volume and value production in comparison with domestic tree species, from the point of view of the soil effects and effects on the ground vegetation diversity, and from point of view of stability and cultivation in the last period. Main aim is represented by the comparison with the Norway spruce, which can be with advantages replaced by this species, with favourable impact on amount and value of the timber production, on the soil and biodiversity status of the ground vegetation. The Norway spruce is heavily affected and endangered by the coming or supposed climatic changes. Also the stability of forest stands can be supported considerably replacing Norway spruce by Douglas-fir. This species can represent suitable alternative to the Norway spruce in lower and middle altitudes and it can contribute highly to the competitiveness not only of the Czech, but European forestry too, increasing stability and production, decreasing the negative effects of the tree species changes in the past.

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