SPHAERULARIA BOMBI DUF. (NEMATODA: ALLANTONEMATIDAE) INFESTING BUMBLEBEES AND SPHAERULARIA HASTATA SP. NOV. INFESTING BARK BEETLES IN CANADA

1957 ◽  
Vol 35 (4) ◽  
pp. 519-523 ◽  
Author(s):  
M. K. Khan

Sphaerularia bombi Duf. is recorded for the first time as a parasite of bumblebee queens in Canada. The nematode was collected from the abdominal cavity of queens of Bombus terricola Kby. and B. ternarius Say from Saskatoon, Saskatchewan.Sphaerularia hastata, sp. nov., is described from the mountain pine beetle, Dendroctonns monticolae Hopk., the Douglas-fir beetle, D. pseudotsugae Hopk., and the cocoon of a hymenopterous parasite, Coeloides dendroctoni Cush., from Steamboat Mountain, British Columbia.

2010 ◽  
Vol 86 (1) ◽  
pp. 87-99 ◽  
Author(s):  
Jodi N. Axelson ◽  
René I. Alfaro ◽  
Brad C. Hawkes

We examined the development of lodgepole pine (Pinus contorta Dougl.) in uneven-aged stands in the Interior Douglasfir (IDF) biogeoclimatic zone of central of British Columbia (B.C.), which are currently undergoing a massive outbreak of the mountain pine beetle (Dendroctonus ponderosae Hopkins; MPB). Using historical ecological approaches, dendrochronology, and stand measurement data, we determined the roles MPB and fire disturbances have played in the ecological processes of lodgepole pine in an Interior Douglas-fir zone. We found that multiple mixed-severity fires created patchy uneven-aged stands dominated by lodgepole pine. Since fire suppression in the 20th century, multiple MPB disturbances have maintained the structural complexity of the stands and favoured regeneration of lodgepole pine in the understory despite the absence of fire, resulting in self-perpetuating multi-age lodgepole pine stands. Analysis of the stand structures remaining after multiple MPB outbreaks showed that, even with high overstory mortality, the sample stands contained several MPB-initiated cohorts, consisting of younger and smaller-diameter lodgepole pine. These surviving lodgepole pine layers, which are less susceptible to beetle, will provide important ecological legacies, and could play an important role in the mid-term timber supply chain. We concluded that, in the absence of fire, the MPB plays a more frequent role in directing stand dynamics and structure in uneven-aged lodgepole pine stands resulting in selfperpetuating complex stands in the central interior. We compared and contrasted these findings with those obtained in “even-aged” lodgepole pine stands, also in the Interior Douglas-fir zone in the southern interior, which were investigated in an earlier study. Key words: lodgepole pine, mountain pine beetle, dendroecology, complex stands, mixed-severity fire regime


1987 ◽  
Vol 119 (5) ◽  
pp. 489-490 ◽  
Author(s):  
A. Syed ◽  
K. Graham

Graham (1968) demonstrated that logs became attractive to ambrosia beetles after the sapwood was subjected to anaerobic conditions. Pursuing this lead, Cade et al. (1970) and Moeck (1970a, 1970b, 1971) extracted, analyzed, and bioassayed anaerobic products from western hemlock and Douglas-fir trees and ascertained that ethanol was the principal “primary attractant” to the ambrosia beetles, Gnathotrichus sulcatus (LeConte) and Trypodendron lineatum (Olivier), respectively. The demonstration that ethanol enhanced the response of the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, to its aggregation pheromones frontalin and seudenol (Pitrnan et al. 1975) suggested that ethanol could also be involved in the primary attraction of or host recognition by bark beetles. We report that the mountain pine beetle, Dendroctonus ponderosae Hopkins, is arrested to ethanol in a laboratorv olfactometer.


2013 ◽  
Vol 91 (4) ◽  
pp. 235-244 ◽  
Author(s):  
A.J. Fleming ◽  
A.A. Lindeman ◽  
A.L. Carroll ◽  
J.E. Yack

Acoustic signaling is widespread in bark beetles (Scolytinae), although little is known about the physical characteristics of signals, how they are transmitted, and how they differ among behavioural contexts. Signals were studied in the male mountain pine beetle (Dendroctonus ponderosae Hopkins, 1902) during stress, male–female, and male–male interactions. Sounds are broadband with significant energy in the ultrasound (peaks between 15 and 26 kHz) and low amplitude (55 and 47 dB SPL at 2 and 4 cm, respectively), indicating that signaling functions at close range. Signal trains vary among contexts primarily in the proportions of chirp types. Chirps were categorized as being simple or interrupted, with the former having significantly lower tooth strike rates and shorter chirp durations. Stress chirps are predominantly simple with characteristics resembling other insect disturbance signals. Male–female interactions begin with the male producing predominantly interrupted chirps prior to gallery entrance, followed by simple chirps. Male–male (rivalry) chirps are predominantly simple, with evidence of antiphonal calling. Substrate-borne vibrations were detectable with a laser-doppler vibrometer at short distances (1–3 cm), suggesting that sensory organs could be tuned to either air or substrate-borne vibrations. These results have important implications for future research on the function and reception of acoustic signals in bark beetles.


2009 ◽  
Vol 39 (4) ◽  
pp. 839-848 ◽  
Author(s):  
V.G. Nealis ◽  
M.K. Noseworthy ◽  
R. Turnquist ◽  
V.R. Waring

The effect of removing lodgepole pine ( Pinus contorta Dougl. ex Loud.) and retaining Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) to reduce the risk of disturbance from mountain pine beetle ( Dendroctonus ponderosae Hopk.) in mixed conifer stands in southern British Columbia, Canada, on population processes influencing outbreaks of western spruce budworm ( Choristoneura occidentalis Free.) was evaluated in 10 paired (open vs. closed) field plots. Overall feeding damage to Douglas-fir was significantly, but only slightly, lower in open stands compared with closed stands. Although open plots tended to recruit more budworms, the losses resulting from the dispersal of spring-emerging budworms in search of feeding sites were significantly greater in open plots. The forest management benefits of these early season losses were mitigated, however, by more mortality of budworms from natural enemies, particularly diseases, in the closed plots during the budworm feeding period. These results are discussed in terms of compensating population processes and balancing objectives in forest pest management. In this case, selective harvesting of lodgepole pine as a mitigation strategy for the mountain pine beetle conserved the midterm timber supply potential represented by associated Douglas-fir even in the presence of an outbreak of the western spruce budworm.


1985 ◽  
Vol 117 (11) ◽  
pp. 1445-1446 ◽  
Author(s):  
Charles E. Richmond

The mountain pine beetle, Dendroctonus ponderosae Hopkins, is one of the most destructive bark beetles found on pine in western North America (McCambridge et al. 1979), particularly in forests of lodgepole pine, Pinus contorta Douglas var. latifolia (Furniss and Carolin 1977). The treatment registered in the United States for the protection of high-value trees in residential areas and recreational areas is 2% carbaryl applied to the bole of the tree with a hydraulic sprayer. Recently, pine oil, a derivative of paper pulp waste, was found to be an effective non-insecticidal repellent against several species of bark beetles (Nijholt et al. 1981).


1987 ◽  
Vol 65 (1) ◽  
pp. 95-102 ◽  
Author(s):  
H. S. Whitney ◽  
R. J. Bandoni ◽  
F. Oberwinkler

A new basidiomycete, Entomocorticium dendroctoni Whitn., Band. & Oberw., gen. et sp. nov., is described and illustrated. This cryptic fungus intermingles with blue stain fungi and produces abundant essentially sessile basidiospores in the galleries and pupal chambers of the mountain pine bark beetle (Dendroctonus ponderosae Hopkins Coleoptera: Scolytidae) in lodgepole pine (Pinus contorta Dougl. var. latifolia Engelm.). The insect apparently disseminates the fungus. Experimentally, young partially insectary reared adult beetles fed E. dendroctoni produced 19% more eggs than beetles fed the blue stain fungi.


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