A Study of the Flight of the Douglas-Fir Beetle Dendroctonus pseudotsugae Hopk. (Coleoptera: Scolytidae): II. Flight Movements

1960 ◽  
Vol 92 (12) ◽  
pp. 941-954 ◽  
Author(s):  
M. D. Atkins

The concern caused by extensive killing of marketable Douglas-fir Pseudotsuga menziesii (Mirb.) Franco, in the interior of British Columbia by the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk., has necessitated studies on many phases of the beetles' biology and behaviour. Among these has been a study of the beetles' flight. Although this insect flies for only a few brief periods during its life, these periods are vital in terms of the extension and location of areas of infestation.

Author(s):  

Abstract A new distribution map is provided for Dendroctonus pseudotsugae Hopkins Coleoptera: Scolytidae Hosts: Mainly Douglas fir (Pseudotsuga menziesii), also other Pseudotsuga spp. Information is given on the geographical distribution in NORTH AMERICA, Canada, Alberta, British Columbia, Mexico, USA, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, Washington, Wyoming.


1998 ◽  
Vol 28 (8) ◽  
pp. 1198-1206 ◽  
Author(s):  
Paige E Axelrood ◽  
William K Chapman ◽  
Keith A Seifert ◽  
David B Trotter ◽  
Gwen Shrimpton

Poor performance of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) plantations established in 1987 has occurred in southwestern British Columbia. Affected sites were planted with 1-year-old container stock that exhibited some root dieback in the nursery. A study was initiated in 1991 to assess Cylindrocarpon and Fusarium root infection in planted and naturally regenerating (natural) Douglas-fir seedlings from seven affected plantations. Percentages of seedlings harboring Cylindrocarpon spp.and percent root colonization were significantly greater for planted seedlings compared with natural seedlings. A significant linear trend in Cylindrocarpon root colonization was observed for planted seedlings with colonization levels being highest for roots closest to the remnants of the root plug and decreasing at distances greater than 10cm from that region. This trend in Cylindrocarpon colonization was not observed for natural seedlings. Cylindrocarpon destructans (Zins.) Scholten var. destructans and C.cylindroides Wollenw. var. cylindroides were the only species isolated from planted and natural conifer seedlings. For most sites, percentage of seedlings harboring Fusarium spp.and percent Fusarium root colonization were less than for Cylindrocarpon. Recovery of Fusarium spp.from seedlings and root colonization levels were not significantly different for planted and natural seedlings from all sites.


Author(s):  

Abstract A new distribution map is provided for Contarinia pseudotsugae Condrashoff (Diptera: Cecidomyiidae). Hosts: Douglas fir (Pseudotsuga menziesii). Information is given on the geographical distribution in Europe (Belgium, France, Germany and Netherlands) and North America (Canada, British Columbia, USA, California, Idaho, Michigan, Montana, Oregon, Pennsylvania and Washington).


Author(s):  

Abstract A new distribution map is provided for Rhabdocline pseudotsugae Syd. Hosts: Douglas fir (Pseudotsuga menziesii). Information is given on the geographical distribution in EUROPE, Belgium, Britain, Czechoslovakia, Denmark, France, Germany, Irish Republic, Netherlands, Norway, Poland, Romania, Sweden, Switzerland, Yugoslavia, NORTH AMERICA, Canada (Alberta, British Columbia), USA.


2018 ◽  
Vol 48 (7) ◽  
pp. 809-820 ◽  
Author(s):  
Neil P. Thompson ◽  
Kathy J. Lewis ◽  
Lisa M. Poirier

Drought tolerance of trees may be affected by competition, but most studies quantifying the relationship do not consider the effect of stem clustering. Trees are often clustered in interior Douglas-fir (Pseudotsuga menziesii var. glauca (Mayr) Franco) forests near the grassland interface in central British Columbia due to past harvesting practices or habitat management for mule deer (Odocoileus hemionus hemionus (Rafinesque, 1817)). Climate change projections indicate continued increases in temperature, an outcome that would stress trees growing in dry environments. Trees placed in different states of competition by mechanical harvesting in the 1970s were sampled to provide a 40-year comparison of three levels of competition during 1–2 year droughts. Tree-ring analysis was used to assess the reduction in growth during drought years and resumption of growth in subsequent years. A clear separation of growth rates was evident between open-growing trees, trees on the edge of harvesting trails, and trees within the unharvested interior. Edge trees had intermediate growth rates but no differences were found in the long-term climate–growth relationship compared with open-growing trees. Both Edge and Open classes showed less relative growth reduction during droughts than Interior trees growing between harvest trails. Precipitation throughfall rates and competition for resources are likely driving short-term drought tolerance in combination with other factors.


2020 ◽  
Vol 113 (4) ◽  
pp. 1858-1863 ◽  
Author(s):  
Gabriel G Foote ◽  
Christopher J Fettig ◽  
Darrell W Ross ◽  
Justin B Runyon ◽  
Tom W Coleman ◽  
...  

Abstract Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, trees and stands can be protected from Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (DFB)-caused mortality by application of synthetic formulations of the beetle’s antiaggregation pheromone, 3-methylcyclohex-2-en-1-one (MCH). A biodegradable formulation of MCH, SPLAT MCH, was developed and evaluated for protecting individual Douglas-fir trees and small stands from colonization and mortality by DFB. In an individual-tree experiment in Idaho, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of treated trees colonized and killed by DFB compared to untreated controls. SPLAT MCH was as effective as MCH bubble capsules for protecting individual trees. Both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB within 0.04-ha circular plots surrounding each treated tree compared to untreated controls. In 0.41 ha stands in New Mexico, both MCH bubble capsules and SPLAT MCH significantly reduced the proportion of trees colonized and killed by DFB compared to untreated controls, again with no differences observed between MCH treatments. In a similar stand level trial in Idaho, neither MCH treatment significantly reduced the proportion of trees colonized by DFB, and only MCH bubble capsules significantly reduced levels of tree mortality compared to untreated controls, but no significant difference was observed between SPLAT MCH and MCH bubble capsules. Overall, the results indicate that SPLAT MCH is as effective as MCH bubble capsules for protecting individual trees and small stands of Douglas-fir from DFB-caused mortality.


2005 ◽  
Vol 20 (3) ◽  
pp. 149-153 ◽  
Author(s):  
Terry L. Shore ◽  
William G. Riel ◽  
Les Safranyik ◽  
Julie Castonguay

Abstract The Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) can cause significant mortality to mature Douglas-fir trees (Pseudotsuga menziesii (Mirb.) Franco) during epidemics. Treatment methods are required to reduce local beetle populations to less-damaging levels. We conducted a study to compare the effect on beetle survival of peeling bark from infested logs at two times of year. By Aug., all beetles in bark from logs peeled in July were dead compared with 155.2 beetles/m2 bark in unpeeled logs. In bark from logs peeled at the end of Aug. and left over winter, there were 3.4 beetles/m2 of bark surface compared with 62.3/m2 in unpeeled logs. It was concluded that peeling logs reduces beetle populations, particularly if done early in the summer. We also examined beetle survival in stumps over winter and found that a mean of 70.4 beetles/stump, or 125.6/m2 of stump surface survived winter. It is estimated that it would take beetles emerging from 24 stumps to kill a tree. West. J. Appl. For. 20(3):149–153.


1962 ◽  
Vol 94 (1) ◽  
pp. 17-25 ◽  
Author(s):  
L. H. McMullen ◽  
M. D. Atkins

The Douglas-fir engraver, Scolytus unispinosus Leconte, is a common bark beetle throughout the Pacific Coast and Rocky Mountain Region of North America. Although it occasionally kills young trees (Chamberlin, 1939), it is of minor economic importance, usually confining its attack to tops, limbs and logging slash. In standing timber it acts primarily as a secondary insect, attacking the tops and branches of trees killed or severely weakened by other agents. In the interior of British Columbia it is commonly found in Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, and thus it is of interest as an associate of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopk. Two other bark beetles Pseudohylesinus nebulosus (Leconte) and Scolytus tsugae (Swaine) with similar associations were studied earlier (Walters and McMullen, 1956; McMullen and Atkins, 1959).


2010 ◽  
Vol 40 (1) ◽  
pp. 155-166 ◽  
Author(s):  
M. G. Cruickshank ◽  
B. Jaquish ◽  
A. F.L. Nemec

The objectives of this study were to (i) develop a methodology for screening conifer seedlings for resistance to Armillaria ostoyae (Romagn.) Herink and (ii) screen a population of interior Douglas-fir ( Pseudotsuga menziesii var. glauca (Biessn.) Franco) population for resistance to A. ostoyae. Eighteen potted seedlings from each of 86 half-sib interior Douglas-fir families were challenged with inoculum in a 3-year greenhouse trial. The seed originated from four geographically distinct tree breeding zones that represent physically and biologically different environments in southeastern British Columbia. Mortality and the final percent survival of inoculated trees showed differences among the families (survival range 0%–61.1%) and breeding zones (survival range 6.6%–25.3%). Maximum heritability index (0.19) occurred at 28 months. Survival analyses revealed that most of the differences in survival could be explained by the zone from which the family originated. The less susceptible seedlings originated from the drier and warmer zones and limited the spread of the fungus in the root system. Moderate levels of family variation in resistance to A. ostoyae and low-moderate heritability suggest that, in interior Douglas-fir, gains in resistance can be achieved through breeding.


1975 ◽  
Vol 53 (20) ◽  
pp. 2297-2302 ◽  
Author(s):  
A. Funk

Three new species of ascomycetes and two coelomycetes are described from diseased Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) from coastal British Columbia, Canada, viz., Coccomyces pseudotsugae n. sp., Phragmoporthe pseudotsugae n. sp., and Botryosphaeria pseudotsugae n. sp.; Phomopsis portei n. sp. and Haplosporella sp. are associated with the latter two ascomycetes, respectively, and possibly represent their conidial states.


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