scholarly journals Factors limiting the northern distribution of the blueberry maggot, Rhagoletis mendax (Diptera: Tephritidae) in Eastern Canada

2016 ◽  
Vol 113 ◽  
pp. 143-149
Author(s):  
Charles VINCENT ◽  
Pierre LEMOYNE ◽  
Sonia GAUL ◽  
Kenna MACKENZIE
Keyword(s):  
Eastern Canada ◽  
Rhagoletis Mendax ◽  
Northern Distribution

Sex-biased trap capture and odor-stimulated upwind flight in the field by Rhagoletis mendax (Diptera: Tephritidae)

2001 ◽  
Vol 133 (2) ◽  
pp. 293-295 ◽  
Author(s):  
L.P.S. Kuenen ◽  
P.J. Silk
Keyword(s):  
Sex Ratio ◽  
Food Availability ◽  
Insect Pest ◽  
Cultural Control ◽  
Orientation Behavior ◽  
Eastern Canada ◽  
Vaccinium Angustifolium ◽  
Sticky Traps ◽  
Rhagoletis Mendax ◽  
Wind Vane

The bluebeny maggot, Rhagoletis mendax Curran, is a primary insect pest of low bush blueberries, Vaccinium angustifolium Ait. (Ericaceae), in eastern Canada. Eggs are laid in ripening berries and mature larvae emerge from the berries to pupate in the soil. Adult flies can be controlled with insecticides (Wood et al. 1983) and (or) cultural control by bum or flail-mow pruning of bushes. Pruned plants do not bear fruit the season after pruning, and this rotation of fruit and nonfruit years is believed to reduce fly populations by limiting food availability (Lathrop 1952). Adult flies can be monitored by capture on yellow-panel sticky traps or red-sphere traps (Prokopy and Coli 1978; Wood et al. 1983; Neilson et al. 1984). In this study, we focused on the sex ratio of R. mendax flies captured on baited and unbaited yellow-panel sticky traps (Pheroco® AM traps) and on the orientation behavior of flies toward wind-vane traps.

scholarly journals Environmental controls of the northern distribution limit of yellow birch in eastern Canada

2014 ◽  
Vol 44 (7) ◽  
pp. 720-731 ◽  
Author(s):  
Igor Drobyshev ◽  
Marc-Antoine Guitard ◽  
Hugo Asselin ◽  
Aurélie Genries ◽  
Yves Bergeron
Keyword(s):  
Growth Patterns ◽  
Betula Alleghaniensis ◽  
Seedling Density ◽  
Yellow Birch ◽  
Eastern Canada ◽  
Large Variability ◽  
Distribution Limit ◽  
Environmental Controls ◽  
Canopy Trees ◽  
Northern Distribution

To evaluate environmental controls of yellow birch (Betula alleghaniensis Britton) distribution at its northern distribution limit in eastern Canada, we analyzed abundance, age structure, biomass accumulation rate, and growth sensitivity to climate of this species at 14 sites along a 200 km latitudinal gradient spanning three bioclimatic domains and reaching frontier populations of this species in western Quebec. We observed a large variability in seedling density across domains and presence of sites with abundant yellow birch regeneration within all three bioclimatic domains. Seedling density was positively correlated to mean age and abundance of yellow birch trees in the canopy, while sapling density was positively associated with dryer habitats. Growth patterns of canopy trees showed no effect of declining temperatures along the south–north gradient. Environmental controls of birch distribution at its northern limit were realized through factors affecting birch regeneration and not growth of canopy trees. At the stand scale, regeneration density was strongly controlled by local site conditions and not by differences in climate among sites. At the regional scale, climate variability could be an indirect driver of yellow birch distribution, affecting disturbance rates and, subsequently, availability of suitable sites for regeneration.

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

Nanofiltration of colored surface water: Quebec's experience

2003 ◽  
Vol 3 (5-6) ◽  
pp. 15-22
Author(s):  
P. Kouadio ◽  
M. Tétrault
Keyword(s):  
Drinking Water ◽  
Surface Water ◽  
Membrane Fouling ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Quebec City ◽  
Water Regulation ◽  
Eastern Canada

Three colored surface water nanofiltration pilot-scale projects were conducted in the province of Quebec (eastern Canada), between November 2000 and March 2002, by the company H2O Innovation (2000) inc., for the municipalities of Lac Bouchette, Latulipe-et-Gaboury and Charlesbourg (now part of Quebec City). Results indicated that nanofiltration permeate quality has an advance on present drinking water regulation standard in Quebec, but important membrane fouling occurred. Fouling can be controlled by pretreatment and optimization of the operating conditions.

EARTHQUAKE SOURCE PARAMETER AND FOCAL MECHANISM ESTIMATES FOR THE WESTERN QUEBEC SEISMIC ZONE IN EASTERN CANADA

2017 ◽  
Author(s):  
Alba M. Rodriguez Padilla ◽  
◽  
John Onwuemeka ◽  
John Onwuemeka ◽  
Yajing Liu ◽  
...  
Keyword(s):  
Focal Mechanism ◽  
Earthquake Source ◽  
Source Parameter ◽  
Seismic Zone ◽  
Eastern Canada

The High-Frequency Decay Slope of Spectra (Kappa) for M≥3.5 Earthquakes on Rock Sites in Eastern and Western Canada

2020 ◽  
Vol 110 (2) ◽  
pp. 471-488 ◽  
Author(s):  
Samantha M. Palmer ◽  
Gail M. Atkinson
Keyword(s):  
Ground Motion ◽  
Classical Method ◽  
Vertical Component ◽  
Western Canada ◽  
S Wave ◽  
Motion Modeling ◽  
Eastern Canada ◽  
General Observation ◽  
Anelastic Attenuation ◽  
Two Parameters

ABSTRACT Spectral decay of ground-motion amplitudes at high frequencies is primarily influenced by two parameters: site-related kappa (κ0) and regional Q (quality factor, inversely proportional to anelastic attenuation). We examine kappa and apparent Q-values (Qa) for M≥3.5 earthquakes recorded at seismograph stations on rock sites in eastern and western Canada. Our database contains 20 earthquakes recorded on nine stations in eastern Canada and 404 earthquakes recorded on eight stations in western Canada, resulting in 105 and 865 Fourier amplitude spectra, respectively. We apply two different methods: (1) a modified version of the classical S-wave acceleration method; and (2) a new stacking method that is consistent with the use of kappa in ground-motion modeling. The results are robust with respect to the method used and also with respect to the frequency band selected, which ranges from 9 to 38 Hz depending on the region, event, and method. Kappa values obtained from the classical method are consistent with those of the stacked method, but the stacked method provides a lower uncertainty. A general observation is that kappa is usually larger, and apparent Q is smaller, for the horizontal component in comparison to the vertical component. We determine an average regional κ0=7  ms (horizontal) and 0 ms (vertical) for rock sites in eastern Canada; we obtain κ0=19  ms (horizontal) and 14 ms (vertical) for rock sites in western Canada. We note that kappa measurements are quite sensitive to details of data selection criteria and methodology, and may be significantly influenced by site effects, resulting in large site-to-site variability.

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