SPRUCE BEETLE (COLEOPTERA: SCOLYTIDAE) SURVIVAL IN STUMPS AND WINDFALL

1999 ◽  
Vol 131 (1) ◽  
pp. 107-113 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Stages Of Development ◽  
Dendroctonus Rufipennis ◽  
Brood Survival ◽  
Host Type ◽  
Spruce Beetle ◽  
Repeated Sampling ◽  
The Mean

AbstractSurvival of the spruce beetle, Dendroctonus rufipennis Kirby, from egg to adult, proportion of 1- and 2-year-cycle adults, and egg and egg gallery production per attack were investigated over five generations in stumps and windfall in central British Columbia. Densities of attacks, egg gallery lengths, and brood in various stages of development were obtained by repeated sampling throughout the life cycle. Spruce beetle populations remained at suboutbreak levels throughout the duration of the study. There were generally no differences by area, host type, or infestation year in any of the measured variables. The mean numbers (±SD) of eggs per attack and eggs per centimetre of egg gallery were 80.8 (54.3) and 5.4 (4.6), respectively. Brood survival from egg to adult averaged 6.8%. The lowest and highest survival from egg to adult occurred in the same years as when the lowest and highest percentage of 1-year-cycle adults were produced, respectively. On average, 51.8% of the beetles in stumps and 19.1% of beetles in windfall developed on a 1-year cycle.

DISTRIBUTION OF ATTACKS ON SPRUCE STUMPS BY THE SPRUCE BEETLE, DENDROCTONUS RUFIPENNIS (KIRBY) (COLEOPTERA: SCOLYTIDAE), AND EFFECTS ON THE LENGTH OF EGG GALLERIES

1988 ◽  
Vol 120 (1) ◽  
pp. 85-94 ◽  
Author(s):  
L. Safranyik ◽  
D.A. Linton
Keyword(s):  
British Columbia ◽  
Theoretical Model ◽  
Density Gradient ◽  
Exponential Function ◽  
Mineral Soil ◽  
Vertical Gradient ◽  
Average Process ◽  
Dendroctonus Rufipennis ◽  
Discrete Step ◽  
Spruce Beetle

AbstractThe distribution of spruce beetle attacks and length of associated egg galleries were investigated on 21 spruce stumps over a 4-year period in central British Columbia. Attack density formed a distinct vertical gradient which peaked near the duff line at about one-third stump height above the mineral soil. The proportion of attacks on the stumps that were located below the duff was linearly related to the ratio of stump height below duff and total stump height above mineral soil. Attack density was significantly higher below the duff than above. A three-parameter exponential function gave satisfactory fit to the attack density gradient on normalized stump height. A discrete-step theoretical model was also developed based on assumptions regarding beetle behavior during landing and imitation of the egg gallery and the physical characteristics of the host. This model gave an excellent fit to the attack density gradient as an average process over all stumps. Average egg gallery length was a curvilinear function of attack density with maximum average egg gallery length occurring at about 0.33 attacks per 100 cm2.

EFFECTS OF SEMIOCHEMICAL BAITING ON THE ATTRACTIVENESS OF FELLED AND UNFELLED LETHAL TRAP TREES FOR SPRUCE BEETLE, DENDROCTONUS RUFIPENNIS (KIRBY) (COLEOPTERA: SCOLYTIDAE), MANAGEMENT IN AREAS OF HIGH AND LOW BEETLE POPULATIONS

1990 ◽  
Vol 122 (2) ◽  
pp. 373-379 ◽  
Author(s):  
D.R. Gray ◽  
E. Holsten ◽  
M. Pascuzzo
Keyword(s):  
British Columbia ◽  
Population Density ◽  
Block Design ◽  
Factorial Experiment ◽  
Combined Effects ◽  
Dendroctonus Rufipennis ◽  
Beetle Population ◽  
Spruce Beetle ◽  
Randomized Complete Block Design

AbstractA two by two factorial experiment in a randomized complete block design tested single and combined effects of tree felling and semiochemical baiting on the attractiveness of spruce (Picea spp.) trees treated with monosodium methanearsenate (MSMA) to Dendroctonus rufipennis (Kirby) in British Columbia and Alaska. In British Columbia, tree felling and semiochemical baiting had significant effects on attack density, but in Alaska only tree felling had a significant effect. Semiochemical baiting had a significant effect on within-tree attack distribution in British Columbia but cot in Alaska, regardless of the felling treatment. The felled treatment captured more beetles than the not-felled treatment regardless of the baiting treatment in British Columbia, but only in the absence of a semiochemical bait in Alaska. The differences between the two locations may have been caused by lower temperatures and beetle population density in Alaska. Effective spruce beetle management with MSMA-treated trees requires tree felling, and beetle capture can be improved with the use of a semiochemical bait.

Experimental Evidence Supporting an Obligate Adult Diapause for Spruce Beetle (Coleoptera: Curculionidae) from British Columbia

2019 ◽  
Vol 49 (1) ◽  
pp. 98-103
Author(s):  
K P Bleiker ◽  
T Willsey
Keyword(s):  
Life Cycle ◽  
Cold Period ◽  
Western Canada ◽  
Dendroctonus Rufipennis ◽  
Emergence Period ◽  
Adult Diapause ◽  
Spruce Beetle ◽  
Developmental Rates ◽  
Almost All ◽  
Developmental Responses

Abstract Insects respond to environmental conditions with a variety of developmental responses which include changing developmental rates, or suppressing development altogether in quiescence or diapause. Such responses have important implications for survival and voltinism. The spruce beetle, Dendroctonus rufipennis Kirby (Coleoptera: Curculionidae), has long been assumed to have an obligatory adult diapause based on field observations that adults always overwinter prior to dispersing and reproducing; however, it has never been experimentally demonstrated and recent evidence suggests that adults in some populations may exhibit facultative tendencies. We examined the emergence of adults at a constant 22°C after exposure to 2°C for 0 (no cold), 25, 50, and 75 d. Our observations of a delayed and extremely protracted emergence period in the absence of a substantive cold period, which could last several months, in combination with rapid, synchronous mass emergence after a substantive cold period, are most consistent with an obligate diapause. Approximately 50% of individuals could complete diapause in 55 d at 2°C, and 75 d of cold was adequate for almost all individuals to complete diapause. Beetles that emerged slowly over time may still have been in diapause; however, additional research would be required to test this hypothesis. Conditions throughout the beetle’s range in Canada should facilitate successful completion of diapause. An obligate adult diapause for spruce beetle populations in western Canada would limit the shortest possible life cycle to 1 yr, but would also serve to maintain an adaptive 1-yr life cycle, especially under a changing climate.

EMERGENCE OF DENDROCTONUS RUFIPENNIS (COLEOPTERA: SCOLYTIDAE) FROM BURIED LOGS

1982 ◽  
Vol 114 (6) ◽  
pp. 539-541
Author(s):  
L. Safranyik ◽  
D.A. Linton
Keyword(s):  
British Columbia ◽  
North America ◽  
Prescribed Burning ◽  
Growing Season ◽  
Forest Industry ◽  
Western North America ◽  
Dendroctonus Rufipennis ◽  
Spruce Beetle ◽  
Logging Residue ◽  
Wet Climate

The spruce beetle, Dendroctonus rufipennis (Kirby), causes periodic, widespread mortality of mature spruce (Picea spp.) in western North America (Massey and Wygant 1954; Schmid and Frye 1977). In British Columbia, logging of infested stands and felling of trap trees are the commonly recommended methods for preventing or suppressing spruce beetle outbreaks. Implicit in these methods is the requirement of treating infested logging residue, and removal for processing of trap trees after the attack period of the spruce beetle. The usual treatment for infested logging residue, prescribed burning, is difficult to carry out in most years because of the generally wet climate of spruce forests during the growing season and the fall period. The forest industry questioned whether burying infested logging residue would be effective in preventing emergence by the spruce beetle. The work described herein addressed this question.

Production of uredinia and telia by stalactiform blister rust in British Columbia

1993 ◽  
Vol 71 (3) ◽  
pp. 519-521 ◽  
Author(s):  
B. J. van der Kamp
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Key Words ◽  
Alternate Host ◽  
Alternate Hosts ◽  
Blister Rust ◽  
Dry Areas ◽  
Do So

Records of uredinia and telia production on the alternate hosts of Cronartium coleosporioides in British Columbia and inoculation of Castilleja miniata with aeciospores collected from various locations showed that rust isolates from dry areas of the interior of British Columbia do not produce uredinia and may have lost the ability to do so. Collections from somewhat wetter areas produced uredinia or mixtures of uredinia and telia immediately following aeciospore inoculations, and field collections from such areas in June commonly had mixtures of uredinia and telia. Loss of the uredinial stage may be a response to climates that are often unsuitable for the spread or survival of the rust on the alternate host. Key words: stalactiform rust, uredinia, telia, rust life cycle.

scholarly journals Time required to move cash through slot machines

2018 ◽  
Vol 21 (3) ◽  
pp. 376-384 ◽  
Author(s):  
Karen Kelly ◽  
Carl James Schwarz ◽  
Ricardo Gomez ◽  
Kim Marsh
Keyword(s):  
British Columbia ◽  
Slot Machines ◽  
Content Type ◽  
The Public ◽  
Average Value ◽  
The Mean ◽  
Time Required ◽  
Rest Breaks ◽  
Mean Time ◽  
Practical Implications

Purpose The purpose of this paper is to present an empirical study on the time needed to load and disburse cash using bill validators on slot machines and stand-alone cash dispensers in casinos in British Columbia under a Ticket In Ticket Out (TITO) system. Design/methodology/approach Testing took place over two days, using 18 machines. The results were extrapolated to estimate the approximate time required to process $1,000,000 with different average bill amounts in the cash mix and three different bill validator machines in common use. The average value per bill using the cash mix used by the public in the casino was $33.11 [standard error (SE) $2.11]. Findings The mean time/accepted note ranged from 4.12 to 9.65 s, depending on bill validator type. This implies that the time needed to load $1,000,000 onto credit slips using bill validators on slot machines ranges from 35 to 81 h, excluding rest breaks and other breaks. The time needed to redeem $1,000,000 is estimated to be 3 h. Practical/implications The implications of these finding for illicit actors to successfully launder large amounts of cash are discussed. Given the time needed to physically handle the cash, and other control systems currently in use in casinos in British Columbia, processing large amounts of cash using bill validators on slot machines would require a highly organized team that would find it difficult to elude detection. Originality/value The trial results provide a baseline estimate to be used going forward when investigating or proposing money laundering methodologies that include slot machines.

COST-EFFECTIVENESS IMPACTS CANCER CARE FUNDING DECISIONS IN BRITISH COLUMBIA, CANADA, EVIDENCE FROM 1998 TO 2008

2017 ◽  
Vol 33 (4) ◽  
pp. 481-486
Author(s):  
Zahra Ismail ◽  
Stuart J. Peacock ◽  
Laurel Kovacic ◽  
Jeffrey S. Hoch
Keyword(s):  
British Columbia ◽  
Cost Effectiveness ◽  
Outcome Measures ◽  
Nonparametric Tests ◽  
Lower Probability ◽  
Economic Evidence ◽  
Cancer Drugs ◽  
Life Years ◽  
Significant Difference ◽  
The Mean

Objectives: The Priorities and Evaluation Committee (PEC) funding recommendations for new cancer drugs in British Columbia, Canada have been based on both clinical and economic evidence. The British Columbia Ministry of Health makes funding decisions. We assessed the association between cost-effectiveness of cancer drugs considered from 1998 to 2008 and the subsequent funding decisions.Methods: All proposals submitted to the PEC between 1998 and 2008 were reviewed, and the association between cost-effectiveness and funding decisions was examined by (i) using logistic regression to test the hypothesis that interventions with higher incremental cost-effectiveness ratios (ICERs) have a lower probability of receiving a positive funding decision and (ii) using parametric and nonparametric tests to determine if a statistically significant difference exists between the mean cost-effectiveness of funded versus not funded proposals. A sub-analysis was conducted to determine if the findings varied across different outcome measures.Results: Of the 149 proposals reviewed, 78 reported cost-effectiveness using various outcome measures. In the proposals that used life-years gained as the outcome (n = 22), a statistically significant difference of nearly $115,000 was observed between the mean ICERs for funded proposals ($42,006) and for unfunded proposals ($156,967). An odds ratio indicating higher ICERs have a lower probability of being funded was also found to be statistically significant (p < .05).Conclusions: Economic evidence appears to play a role in British Columbia cancer funding decisions from 1998 to 2008; other decision-making criteria may also have an important role in recommendations and subsequent funding decisions.

Fecundity and Egg Retention of Some Sockeye Salmon (Oncorhynchus nerka) Stocks in British Columbia

1986 ◽  
Vol 43 (8) ◽  
pp. 1643-1655 ◽  
Author(s):  
J. I. Manzer ◽  
I. Miki
Keyword(s):  
British Columbia ◽  
Sockeye Salmon ◽  
Oncorhynchus Nerka ◽  
Absolute Fecundity ◽  
Egg Retention ◽  
Inadequate Sample Size ◽  
Egg Number ◽  
The Mean ◽  
The Relationship ◽  
Individual Fecundity

The fecundity and egg retention of anadromous female sockeye salmon (Oncorhynchus nerka) collected during 1971–82 from several stocks in British Columbia undergoing controlled fertilization to enhance adult sockeye production were examined. The relationship between egg number and postorbital–hypural length based on 863 females representing 14 stocks was not consistent between all age-types, stocks, and years, probably because of inadequate sample size in some instances. Combined samples, however, revealed a significant positive relationship between postorbital–hypural length and egg number for age 1.2, 1.3, and 2.2 females. Mean absolute fecundity for the respective age-types was 3218, 4125, and 3544 eggs. For samples of 10 or more females, significant stock and annual differences were detected when individual mean absolute fecundity was adjusted to a postorbital–hypural length of 447 mm, but not for females of different age. A comparison of mean fecundities for coastal stocks with historical data for interior British Columbia stocks suggests that coastal stocks are 18% more fecund than interior stocks. Possible causal mechanisms for this regional difference are hypothesized. Examination of 796 carcasses (representing five stocks) for egg retention revealed a range from totally spawned to totally unspawned females, with 56% of the carcasses containing 20 eggs or less and 68% containing 50 eggs or less. The mean egg retention based on all samples combined was estimated to be 6.5% of the mean individual fecundity. This value was reduced to 3.9% when stock means were averaged.

THE POPLAR-AND-WILLOW BORER, STERNOCHETUS (= CRYPTORHYNCHUS) LAPATHI (COLEOPTERA: CURCULIONIDAE), IN BRITISH COLUMBIA

1967 ◽  
Vol 99 (4) ◽  
pp. 411-418 ◽  
Author(s):  
John W. E. Harris ◽  
Harry C. Coppel
Keyword(s):  
British Columbia ◽  
Life Cycle ◽  
Larval Mortality ◽  
Vancouver Island ◽  
Water Emulsion ◽  
Early Instar ◽  
Preferred Hosts ◽  
North Latitude

AbstractA study was made of the poplar-and-willow borer, Sternochetus (= Cryptorhynchus) lapathi (L.) (Coleoptera: Curculionidae), in British Columbia between 1959 and 1964. The borer occurred principally south of 52 degrees north latitude. Willows were the preferred hosts. Ornamentals, hybrids in commercial plantings, and natural growing trees were attacked. The life cycle of the insect on southern Vancouver Island lasted up to 3 years; overwintering took place in early instar and adult stages. Eggs were laid in the bark; larvae mined first in the bark and then in the wood, where pupation took place. Few parasites and predators were found. DDT, dieldrin, and BHC killed adults; lindane (0.5% water emulsion), applied in the spring, caused larval mortality up to 96%.

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