INTERPOPULATION DIFFERENCES IN THE COLDHARDINESS OF DELIA RADICUM (DIPTERA: ANTHOMYIIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 119-129 ◽  
Author(s):  
W.J. Turnock ◽  
G. Boivin ◽  
R.A. Ring
Keyword(s):  
British Columbia ◽  
North America ◽  
Cold Injury ◽  
Delia Radicum ◽  
Regression Equations ◽  
Founder Populations ◽  
The Mean ◽  
Cabbage Root Maggot ◽  
Lower Temperature ◽  
Root Maggot

AbstractThe cabbage root maggot, Delia radicum (L.), was introduced to North America in the mid-1800s, likely from northwestern Europe, and probably reached Quebec and British Columbia before 1885 and Manitoba by 1922. The mean temperature of crystallization (Tc) for overwintering pupae was −22.8 ± 1.2 °C for the St-Jean-sur-Richelieu, Quebec, population and −23.8 ± 0.7 °C for the Vancouver, British Columbia, population. The mean Tc for these two populations and for Winnipeg, Manitoba (−24.4 °C), Ascot, England (−22.8 °C), Tallinn, Estonia (−25.2 °C), and St. Petersburg, Russia (ca. −20 °C), did not show any relation to mean January temperatures. These locations represent both temperate oceanic and temperate continental climates and a range of mean January temperatures from +4.6 to −17.7 °C. Survival of puparia from St-Jean-sur-Richelieu exposed to nonfreezing temperatures decreased as temperature decreased and exposure time lengthened. The parameters for the regression equations describing this relationship were similar to those describing the Winnipeg population, and both were more coldhardy than the Ascot population. The upper limit of the cold injury zone (ULCIZ) for the St-Jean-sur-Richelieu population was −12.7 °C and the lower limit of this zone (LLCIZ) was −27.6 °C. Coldhardy populations from temperate continental climates (St-Jean-sur-Richelieu, Winnipeg) showed a rate of decrease in survival with increased cold stress (lower temperature, longer exposure) within the cold injury zone which was much slower than in the less coldhardy population (Ascot). Thus, some individuals from the coldhardy populations would be physiologically capable of surviving exposure to temperatures below Tc, whereas in the Ascot population nonfreezing injury would kill all the overwintering puparia at a temperature (−19.6 °C) well above Tc (−22.8 °C). The observed survival of puparia from Vancouver, following various nonfreezing exposures, resembled more closely the calculated survival for these exposures when the equations describing the Ascot population were used than when the equations for Winnipeg or St-Jean-sur-Richelieu were used. The Ascot and Vancouver populations, both from temperate oceanic climates, are less coldhardy than the populations from St-Jean-sur-Richelieu and Winnipeg (temperate continental climates). The founder populations of D. radicum in North America, which probably originated in the temperate oceanic climates of northwestern Europe, have adapted to the colder temperate continental climates by increasing their ability to survive longer exposures to all temperatures within the cold injury zone and not by lowering Tc. Therefore, selection for coldhardiness in D. radicum must have operated on structures, processes, or physiological-biochemical mechanisms that help the organism to avoid or repair nonfreezing cold injury but not on those that determine Tc.

ROOT MAGGOT DAMAGE TO CANOLA AND THE DISTRIBUTION OF DELIA SPP. (DIPTERA: ANTHOMYIIDAE) IN MANITOBA

1992 ◽  
Vol 124 (1) ◽  
pp. 49-58 ◽  
Author(s):  
W.J. Turnock ◽  
B. Timlick ◽  
B.E. Galka ◽  
P. Palaniswamy
Keyword(s):  
First Generation ◽  
Delia Radicum ◽  
Feeding Damage ◽  
Yield Losses ◽  
Significant Yield ◽  
The Mean ◽  
Cabbage Root Maggot ◽  
Root Maggot ◽  
Agricultural Regions ◽  
Increasing Precipitation

AbstractThe cabbage root maggot, Delia radicum (L.), was the only Delia species capable of attacking undamaged roots of canola [oilseed rape, Brassica napus (L.)] that was found in commercial fields in Manitoba. Adults of the overwintering generation infest canola. Their progeny, adults of the first generation, left the maturing plants after completing a single generation. Root maggot damage occurred in fields in all agricultural regions of the province. The mean percentage of the roots with damage was higher in the more northerly agricultural regions (15.8%) than in the south (8.0%). Most of the damage was light and the damage did not visibly affect the growth or vigour of the plants. Foot rot fungi were not associated with the feeding damage. In cage experiments, the seed yield of canola did not decrease with increasing proportions of plants damaged by D. radicum. The percentage of plants with root maggot damage (DAM) was best described in a polynomial by the mean daily air temperature (TEMP) and the total precipitation (RAIN) for June and July:log(DAM + 1)=–12.3 + 0.66 TEMP + 0.09 RAIN – 0.004(TEMP × RAIN).The level of damage caused by the larvae of D. radicum to canola in commercial fields during the years 1985 through 1988 did not appear to have caused yield losses. However, the level of damage increased with increasing precipitation and temperature during June and July so a series of favourable years could lead to increased damage and possibly to significant yield losses.

scholarly journals Erroneous records of Aleochara bipustulata from North America: an assessment of the evidence

2005 ◽  
Vol 137 (2) ◽  
pp. 182-187 ◽  
Author(s):  
K.S. Hemachandra ◽  
N.J. Holliday ◽  
J. Klimaszewski ◽  
P.G. Mason ◽  
U. Kuhlmann
Keyword(s):  
North America ◽  
Classical Biological Control ◽  
Delia Radicum ◽  
Museum Specimens ◽  
Canadian Prairie ◽  
Aleochara Bilineata ◽  
Palearctic Species ◽  
Cabbage Root Maggot ◽  
Taxonomic Studies ◽  
Root Maggot

AbstractAleochara bipustulata (L., 1761) (Coleoptera: Staphylinidae) is a Palearctic species and a natural enemy of the cabbage root maggot, Delia radicum (L., 1758) (Diptera: Anthomyiidae). It has been identified as a candidate for introduction to Canada for classical biological control of D. radicum. Recent taxonomic studies assert that A. bipustulata is absent from the Nearctic; however, there are numerous publications reporting the presence of the species in North America. We examined voucher material relating to these publications and additional museum specimens labeled as A. bipustulata. In addition, we reared Aleochara spp. from D. radicum puparia collected in the Canadian prairie provinces. Specimens that, based on external anatomy, could be A. bipustulata were definitively identified using characters of the genitalia. All of the 141 museum specimens labeled A. bipustulata were found to be Aleochara verna Say, 1836. A total of 811 individuals of Aleochara spp. were reared from D. radicum puparia; of these, 690 were Aleochara bilineata Gyllenhal, 1810, 121 were A. verna, and none were A. bipustulata. We have found no evidence that A. bipustulata occurs in North America.

Paleomagnetism of the Upper Cretaceous Nanaimo Group, southwestern Canadian Cordillera

2001 ◽  
Vol 38 (10) ◽  
pp. 1403-1422 ◽  
Author(s):  
Randolph J Enkin ◽  
Judith Baker ◽  
Peter S Mustard
Keyword(s):  
British Columbia ◽  
North America ◽  
Upper Cretaceous ◽  
Vertical Axis ◽  
Vancouver Island ◽  
Canadian Cordillera ◽  
Paleontological Data ◽  
The Mean ◽  
Prime Target

The Baja B.C. model has the Insular Superterrane and related entities of the Canadian Cordillera subject to >3000 km of northward displacement with respect to cratonic North America from ~90 to ~50 Ma. The Upper Cretaceous Nanaimo Group (on and about Vancouver Island, British Columbia) is a prime target to test the model paleomagnetically because of its locality and age. We have widely sampled the basin (67 sites from seven islands spread over 150 km, Santonian to Maastrichtian age). Most samples have low unblocking temperatures (<450°C) and coercivities (~10 mT) and strong present-field contamination, forcing us to reject three quarters of the collection. Beds are insufficiently tilted to provide a conclusive fold test, and we see evidence of relative vertical axis rotations. However, inclination-only analysis indicates pretilting remanence is preserved for many samples. Both polarities are observed, and reversals correlate well to paleontological data, proving that primary remanence is observed. The mean inclination, 55 ± 3°, is 13 ± 4° steeper than previously published results. Our new paleolatitude, 35.7 ± 2.6° is identical to that determined from the slightly older Silverquick and Powell Creek formations at Mount Tatlow, yet the inferred displacement is smaller (2300 ± 400 km versus 3000 ± 500 km) because North America was drifting southward starting around 90 Ma. The interpreted paleolatitude conflicts with sedimentologic and paleontologic evidence that the Nanaimo Basin was deposited near its present northern position.

scholarly journals Spatial distribution of cabbage root maggot (Delia radicum) and clubroot (Plasmodiophora brassicae) in winter oilseed rape crops in the Czech Republic

2017 ◽  
Vol 53 (No. 3) ◽  
pp. 159-168
Author(s):  
Hlavjenka Vojtěch ◽  
Seidenglanz Marek ◽  
Dufek Aleš ◽  
Šefrová Hana
Keyword(s):  
Spatial Distribution ◽  
Czech Republic ◽  
Oilseed Rape ◽  
Plasmodiophora Brassicae ◽  
Surface Damage ◽  
Root Surface ◽  
Delia Radicum ◽  
Winter Oilseed Rape ◽  
Cabbage Root Maggot ◽  
Root Maggot

The amount and spatial distribution of plants afflicted with cabbage root maggot (Delia radicum; CRM) and clubroot (Plasmodiophora brassicae) in winter oilseed rape crops were assessed in the Olomouc region (Northern Moravia, Czech Republic) over the course of 2012–2014. A total of 16 commercial rape fields were included in the assessments. Plants with tumours showed a significantly lower (P &lt; 0.001) level of infestation induced by CRM (24% of plants infested) compared to plants without tumours (37% of plants infested). According to a generalised linear mixed model, plants with thicker hypocotyls are predisposed to significantly higher levels (P &lt; 0.001) of root surface damage induced by CRM. The correlation analysis indicates rather weak or intermediate levels of correlation between the two variables (hypocotyls thickness × root surface damage induced by CRM). Both CRM and clubroot symptomatic plants showed a significant tendency for aggregation in rape crops, but not in all cases. Distributions of CRM and clubroot symptomatic plants were either significantly spatially dissociated or not associated in crops. Ovipositing D. radicum females showed some tendency to avoid zones with higher number of plants infected by P. brassicae. Distributions of CRM and hypocotyl thickness levels were significantly spatially associated in crops in several cases.

Cold-hardiness of Lacanobia atlantica (Lepidoptera: Noctuidae), and a comparison with three other insect species that overwinter in the same habitat

1993 ◽  
Vol 71 (9) ◽  
pp. 1710-1714 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Cold Hardiness ◽  
Cold Injury ◽  
Delia Radicum ◽  
Upper And Lower Bounds ◽  
Supercooling Point ◽  
Response Curves ◽  
The Mean ◽  
Response To Temperature ◽  
Lepidoptera Noctuidae ◽  
Athrycia Cinerea

The pupae of Lacanobia atlantica (Grt.) overwinter in the soil and are susceptible to freezing. Cold injury and death occur at temperatures above the supercooling point (SCP) of −26.4 °C, and below ca. −12.6 °C. Mortality increases as temperature decreases and as exposure lengthens. These results are compared with those for Mamestra configurata Wlk., Delia radicum (L.), and Athrycia cinerea Coq., which have similar overwintering habits. Their mean SCPs (−27.3 to −20.3 °C) differ less than do the values representing the highest temperature at which cold injury occurs (≈−12.6 to ≈4 °C). Response curves of three of the species were similar for changes in temperature and duration of exposure, and similarly in a plot of the time to 50% survival (LT50) against temperature. They differed only in their relative cold-hardiness. In contrast, A. cinerea was less sensitive to changes in temperature and duration of exposure. A single parameter (e.g., the mean SCP) is not adequate to describe the cold-hardiness of these species because they vary not only in the upper and lower bounds of their cold-injury zones but also in their response to temperature and duration of exposure within this zone.

Upper limit of docking time for Stikinia and Terrane I: paleomagnetic evidence from the Eocene Ootsa Lake Group, British Columbia

1990 ◽  
Vol 27 (2) ◽  
pp. 212-218 ◽  
Author(s):  
T. A. Vandall ◽  
H. C. Palmer
Keyword(s):  
British Columbia ◽  
North America ◽  
Large Scale ◽  
Middle Eocene ◽  
Pole Position ◽  
Upper Limit ◽  
Plutonic Complex ◽  
Coast Plutonic Complex ◽  
The Mean ◽  
Reversed Polarity

The Middle Eocene Ootsa Lake Group is exposed in the central portion of the Stikine Terrane, where it was sampled along the shoreline of Tahtsa Reach and Whitesail Reach. The group consists of dominantly subaerial flows, which range in composition from basalt to rhyolite, that unconformably overly the Jurassic Hazelton Group. Detailed alternating-field and thermal stepwise demagnetizations were done on all specimens from the 21 sites collected. The presence of a normal- and reversed-polarity remanence, a positive fold test, and high coercivities and unblocking temperatures indicate that a prefolding primary remanence has been isolated. The mean tilt-corrected direction of D = 002.2°, I = 69.2 °(α95 = 7.4°) from 13 sites for which paleohorizontal is well known yields a pole position at 354.6°E, 88.0°N (A95 = 11.5°), which is statistically indistinguishable from published 50 Ma reference poles for cratonic North America. This evidence demonstrates that the proposed large-scale northward displacement of Stikinia since mid-Cretaceous was completed by at least Middle Eocene time. This result is consistent with other paleomagnetic results from Stikinia, Quesnellia, and the Coast Plutonic Complex indicating that much of the allochthonous Cordillera had assembled and docked with cratonic North America by the Middle Eocene.

scholarly journals Analysis of aircraft and satellite measurements from the Intercontinental Chemical Transport Experiment (INTEX-B) to quantify long-range transport of East Asian sulfur to Canada

2008 ◽  
Vol 8 (11) ◽  
pp. 2999-3014 ◽  
Author(s):  
A. van Donkelaar ◽  
R. V. Martin ◽  
W. R. Leaitch ◽  
A. M. Macdonald ◽  
T. W. Walker ◽  
...  
Keyword(s):  
British Columbia ◽  
North America ◽  
Long Range ◽  
East Asian ◽  
Chemical Transport ◽  
Long Range Transport ◽  
Free Troposphere ◽  
Range Transport ◽  
Transport Experiment ◽  
Sulfur Emissions

Abstract. We interpret a suite of satellite, aircraft, and ground-based measurements over the North Pacific Ocean and western North America during April–May 2006 as part of the Intercontinental Chemical Transport Experiment Phase B (INTEX-B) campaign to understand the implications of long-range transport of East Asian emissions to North America. The Canadian component of INTEX-B included 33 vertical profiles from a Cessna 207 aircraft equipped with an aerosol mass spectrometer. Long-range transport of organic aerosols was insignificant, contrary to expectations. Measured sulfate plumes in the free troposphere over British Columbia exceeded 2 μg/m3. We update the global anthropogenic emission inventory in a chemical transport model (GEOS-Chem) and use it to interpret the observations. Aerosol Optical Depth (AOD) retrieved from two satellite instruments (MISR and MODIS) for 2000–2006 are analyzed with GEOS-Chem to estimate an annual growth in Chinese sulfur emissions of 6.2% and 9.6%, respectively. Analysis of aircraft sulfate measurements from the NASA DC-8 over the central Pacific, the NSF C-130 over the east Pacific and the Cessna over British Columbia indicates most Asian sulfate over the ocean is in the lower free troposphere (800–600 hPa), with a decrease in pressure toward land due to orographic effects. We calculate that 56% of the measured sulfate between 500–900 hPa over British Columbia is due to East Asian sources. We find evidence of a 72–85% increase in the relative contribution of East Asian sulfate to the total burden in spring off the northwest coast of the United States since 1985. Campaign-average simulations indicate anthropogenic East Asian sulfur emissions increase mean springtime sulfate in Western Canada at the surface by 0.31 μg/m3 (~30%) and account for 50% of the overall regional sulfate burden between 1 and 5 km. Mean measured daily surface sulfate concentrations taken in the Vancouver area increase by 0.32 μg/m3 per 10% increase in the simulated fraction of Asian sulfate, and suggest current East Asian emissions episodically degrade local air quality by more than 1.5 μg/m3.

Japewia Subaurifera, A New Lichen Genus and Species From North-West Europe and Western North America

1990 ◽  
Vol 22 (3) ◽  
pp. 205-212 ◽  
Author(s):  
T. Tønsberg
Keyword(s):  
British Columbia ◽  
North America ◽  
Western North America ◽  
Coniferous Trees ◽  
North West

AbstractThe genus Japewia Tønsb. is introduced to accommodate three species including J. subaurifera Muhr & Tønsb. sp. nov. based on material from Norway, Sweden, Finland, Scotland, Canada (British Columbia) and U.S.A. (Washington). This species is closely related to Lecidea tornoensis Nyl. but is distinguished in being sorediate and by the production of lobaric acid (accessory) and acetone-soluble pigments. It grows on bark of deciduous and coniferous trees. Lecidea carrollii Coppins & P. James and L. tornoensis Nyl. are transferred to Japewia.

The Lower Jurassic phosphorites of southeastern British Columbia and terrane accretion to western North America

1989 ◽  
Vol 26 (8) ◽  
pp. 1612-1616 ◽  
Author(s):  
T. P. Poulton ◽  
J. D. Aitken
Keyword(s):  
British Columbia ◽  
North America ◽  
Oceanic Crust ◽  
West Coast ◽  
Cold Water ◽  
Lower Jurassic ◽  
Depositional Model ◽  
Western North America ◽  
The West ◽  
Terrane Accretion

Sinemurian phosphorites in southeastern British Columbia and southwestern Alberta conform with the "West Coast type" phosphorite depositional model. The model indicates that they were deposited on or near the Early Jurassic western cratonic margin, next to a sea or trough from which cold water upwelled. This suggests that the allochthonous terrane Quesnellia lay well offshore in Sinemurian time. The sea separating Quesnellia from North America was partly floored by oceanic crust ("Eastern Terrane") and partly by a thick sequence of rifted, continental terrace wedge rocks comprising the Purcell Supergroup and overlying Paleozoic sequence. This sequence must have been depressed sufficiently that access of upwelling deep currents to the phosphorite depositional area was not impeded.

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