REQUIRED SAMPLE SIZE FOR EARLY INSTAR LARVAE OF SPRUCE BUDWORM,CHORISTONEURA FUMIFERANA(LEPIDOPTERA: TORTRICIDAE), IN NEWFOUNDLAND

1983 ◽  
Vol 115 (11) ◽  
pp. 1523-1527 ◽  
Author(s):  
E. J. Dobesberger ◽  
K. P. Lim
Keyword(s):  
Population Density ◽  
Sample Size ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Early Instar

AbstractRequired sample size was determined for early instar (2nd to 4th instar) larvae of spruce budworm,Choristoneura fumiferana(Clem.). Larval counts on mid-crown 45 cm branch tips and whole branches of balsam fir,Abies balsamea(L.) Mill., were described in terms of the negative binomial distribution. The values of commonkfor the branch tip and whole branch sample units were 1.550 and 1.636, respectively. The required sample size at densities greater than or equal to one appears feasible. It is recommended that the 45 cm branch tip be used to estimate population density of early instar larvae in Newfoundland.

EFFICACY OF FORAY 48B (BACILLUS THURINGIENSIS BERLINER) APPLICATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEMENS) (LEPIDOPTERA: TORTRICIDAE), TIMED FOR PHENOLOGICAL DEVELOPMENT OF BALSAM FIR AND BLACK SPRUCE

1993 ◽  
Vol 125 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Beresford L. Cadogan ◽  
Roger D. Scharbach
Keyword(s):  
Bacillus Thuringiensis ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Balsam Fir ◽  
Early Instar ◽  
Respective Species ◽  
Respective Host

AbstractThe insecticide Foray 48B (Bacillus thuringiensis var. kurstaki Berliner) was applied undiluted at 30 BIU per ha to control spruce budworm, Choristoneura fumiferana (Clem.), in a mixed boreal forest stand of balsam fir, Abies balsamea (L.) Mill., and black spruce, Picea mariana (Mill.) B.S.P. When the treatment was timed to coincide with the early flushing of balsam fir shoots, the corrected budworm population reductions were 74 and 52% on balsam fir and black spruce, respectively. This treatment resulted in 19 and 8% defoliation on the two respective species. When the insecticide application was timed later to coincide with the late flushing of black spruce shoots the corrected population reductions were 93% on balsam fir and 72% on black spruce. Defoliation of the two species was 29 and 10% respectively, following this treatment. Larval survival on both species after the spray timed for black spruce (0.8 and 2.2 larvae per 45-cm branch on balsam fir and black spruce, respectively) was significantly less (P = 0.05) than that observed after the spray timed for balsam fir (4.6 and 4.2 larvae per 45-cm branch on the respective host species).The data indicate that the spray timed to correspond with the flushing of black spruce was generally more efficacious than the spray timed to impact on newly flushed balsam fir; nevertheless, the results raise the question as to how B. thuringiensis insecticides impact on early-instar budworm larvae when there is no preferred current year foliage on which the insects can feed.

Weather and Outbreaks of the Spruce Budworm in the Province of Quebec from 1939 to 1956

1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
The Past ◽  
Forest Regions ◽  
Tree Component ◽  
Gaspe Peninsula ◽  
Gaspé Peninsula

Nearly all forest regions in the Province of Quebec where balsam fir (Abies balsamea (L.) Mill.) is an important tree component have been subjected to severe defoliation by the spruce budworm, Choristoneura fumiferana (Clem.), during the past 20 years. These outbreaks have followed an easterly direction beginning near the Ontario-Quebec border in 1939 and ending in the Gaspé Peninsula in 1958.

Prescribed Burning for Stand Conversion in Budworm-killed Balsam Fir: An Ontario Case History

1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae
Keyword(s):  
Fuel Consumption ◽  
Prescribed Burning ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Fire Spread ◽  
Fire Effects ◽  
Balsam Fir ◽  
Prescribed Burn ◽  
Stand Conversion

Recent spruce budworm (Choristoneura fumiferana [Clem.]) infestations have resulted in widespread areas of balsam fir (Abies balsamea [L.] Mill.) mortality in Ontario, and there is growing interest in reestablishing these areas quickly as productive forests. One technique being used is prescribed fire after a salvage and bulldozer tramping operation. A 445-ha prescribed burn was carried out under moderate fire danger conditions in northern Ontario. The site, which was covered by balsam fir fuel that had been killed by spruce budworm, was tramped to improve fire spread. Weather, fuel consumption, and fire effects are reported. The burn effectively reduced heavy surface fuel loadings and consequently planting on the site was easier. Key words: Prescribed burning, fire, spruce budworm. Choristoneura fumiferana, balsam fir, Abies balsamea, fuel consumption, site preparation, tramping, stand conversion.

LONG TERM STUDY OF THE EFFECTIVENESS OF AERIAL APPLICATION OF BACILLUS THURINGIENSIS – ACEPHATE COMBINATIONS AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Larval Mortality ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Population Densities ◽  
Long Term Study

AbstractBacillus thuringiensis (Dipel® 36B) mixed with a sublethal concentration of acephate (Orthene®) (O, S-dimethyl acetylphosphoramidothioate), an organophosphorous insecticide, was applied at 2.35–14 l./ha to white spruce (Picea glauca) and balsam fir (Abies balsamea) trees infested with spruce budworm, Choristoneura fumiferana (Clem.). The treatment rate was 20 Billion International Units of B. thuringiensis (B.t.) activity with or without 42 g of active ingredient of acephate/ha.The ground deposit of the standard Dipel wettable powder formulation was 12% of emitted volume compared with 21–32% for the Dipel 36B flowable. The viability of B.t. spores was drastically reduced after 1 day of weathering but a high level of biological activity by the spore–crystal complex persisted for up to 20 days post-spray due probably to crystal activity.The addition of about 10% of the recommended operational rate of acephate to the B.t. suspension increased larval mortality by 34% when applied at 4.7 l./ha. Reductions in budworm populations were 97–99% in B.t. + acephate plots and 86–90% in B.t. alone plots.Plots with moderate budworm densities of up to 27 larvae/100 buds on white spruce and 36/100 on balsam fir were satisfactorily protected from excessive defoliation in the year of spray by B.t. with or without acephate. Plots with higher population densities were not satisfactorily protected based on the branch sample examination but aerial color photographs indicated good protection to the top third of the trees. Population declines were greater and defoliation and oviposition were lower in the treated plots than in the untreated checks 1 year later without further treatment. Two years later the larval population densities in all plots were low but the density was twice as high in the untreated check as in the treated plots, indicating long term suppression by the treatments. Defoliation was negligible in all plots.The treatments had no deleterious effect on spruce budworm parasitism. The data indicate that the integrated approach using Bacillus thuringiensis – chemical pesticide combinations is a viable alternative to the use of chemical pesticides alone in spruce budworm control. Large scale testing is now warranted.

CHANGES IN SPRUCE BUDWORM DEFOLIATION WITH CROWN LEVEL

1996 ◽  
Vol 128 (6) ◽  
pp. 1109-1113 ◽  
Author(s):  
Harald Piene
Keyword(s):  
Nova Scotia ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Cost Effective ◽  
Balsam Fir ◽  
Crown Length ◽  
Cape Breton ◽  
Cost Effective Approach ◽  
The Common

AbstractDetailed estimates of defoliation caused by spruce budworm [Choristoneura fumiferana (Clem.)] over the crown length of young balsam fir [Abies balsamea (L.) Mill.] were made throughout a spruce budworm outbreak from 1976 to 1984 in the Cape Breton Highlands, Nova Scotia. The results show no clear tendency for a particular level of the crown to be damaged more heavily than any other. Thus, there is no reason to continue the common practice of taking samples from the mid-crown level on the assumption that they represent an ‘average’ level of defoliation either for high or low populations. Sampling from the bottom of the crown should provide a more convenient and cost-effective approach for estimating defoliation.

scholarly journals Sampling Hazelnuts for Aflatoxin: Effect of Sample Size and Accept/Reject Limit on Reducing the Risk of Misclassifying Lots

2007 ◽  
Vol 90 (4) ◽  
pp. 1028-1035 ◽  
Author(s):  
Guner Ozay ◽  
Ferda Seyhan ◽  
Aysun Yilmaz ◽  
Thomas B Whitaker ◽  
Andrew B Slate ◽  
...  
Keyword(s):  
Sample Size ◽  
Negative Binomial Distribution ◽  
Binomial Distribution ◽  
Negative Binomial ◽  
Food Additives ◽  
Sampling Plan ◽  
Test Results ◽  
Sampling Plans ◽  
Wide Range ◽  
Sample Test

Abstract About 100 countries have established regulatory limits for aflatoxin in food and feeds. Because these limits vary widely among regulating countries, the Codex Committee on Food Additives and Contaminants began work in 2004 to harmonize aflatoxin limits and sampling plans for aflatoxin in almonds, pistachios, hazelnuts, and Brazil nuts. Studies were developed to measure the uncertainty and distribution among replicated sample aflatoxin test results taken from aflatoxin-contaminated treenut lots. The uncertainty and distribution information is used to develop a model that can evaluate the performance (risk of misclassifying lots) of aflatoxin sampling plan designs for treenuts. Once the performance of aflatoxin sampling plans can be predicted, they can be designed to reduce the risks of misclassifying lots traded in either the domestic or export markets. A method was developed to evaluate the performance of sampling plans designed to detect aflatoxin in hazelnuts lots. Twenty hazelnut lots with varying levels of contamination were sampled according to an experimental protocol where 16 test samples were taken from each lot. The observed aflatoxin distribution among the 16 aflatoxin sample test results was compared to lognormal, compound gamma, and negative binomial distributions. The negative binomial distribution was selected to model aflatoxin distribution among sample test results because it gave acceptable fits to observed distributions among sample test results taken from a wide range of lot concentrations. Using the negative binomial distribution, computer models were developed to calculate operating characteristic curves for specific aflatoxin sampling plan designs. The effect of sample size and accept/reject limits on the chances of rejecting good lots (sellers' risk) and accepting bad lots (buyers' risk) was demonstrated for various sampling plan designs.

OPTIMAL SAMPLE SIZE FOR THE ESTIMATION OF SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) POPULATIONS ON BALSAM FIR AND WHITE SPRUCE

1983 ◽  
Vol 115 (12) ◽  
pp. 1621-1626 ◽  
Author(s):  
Jacques Régnière ◽  
C. J. Sanders
Keyword(s):  
Population Density ◽  
Sample Size ◽  
Host Species ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Larval Population ◽  
Optimal Sample Size ◽  
Optimal Sample

AbstractAn equation is presented for the determination of sample sizes needed to estimate with a given precision the larval population density of spruce budworm on balsam fir and white spruce branch tips in Ontario. This equation is primarily applicable to low densities, but is valid to a density of 50 larvae/branch tip. The distribution of budworm larvae at densities below 0.1/branch tip is nearly random, and is aggregated at higher densities. Their distribution is the same on the two host species.

Demography and spatial dynamics in balsam fir stands after a spruce budworm outbreak

2011 ◽  
Vol 41 (5) ◽  
pp. 1112-1120 ◽  
Author(s):  
Sergio Rossi ◽  
Hubert Morin
Keyword(s):  
Choristoneura Fumiferana ◽  
Spatial Scales ◽  
Spatial Dynamics ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Permanent Plots ◽  
Random Pattern ◽  
Advance Regeneration ◽  
Competition For Resources

The renewal of balsam fir (Abies balsamea (L.) P. Mill.) stands is related to the recurrent spruce budworm (Archips fumiferana Clemens [syn.: Choristoneura fumiferana (Clemens)]) outbreaks that favour the growth of the regeneration following death of the dominant trees. The aim of this study was to investigate the population demography and the spatial relationships among individuals in four permanent plots of the boreal forest of Quebec, Canada, after a spruce budworm outbreak. This was realized by collecting data on trees and saplings every five years from 1994 to 2004 and by using Ripley’s K statistics. The younger plots showed recruitment of up to 90 new trees·ha–1·year–1, and mortality following competition among individuals affected up to 27% and 50% of the trees and saplings, respectively. In the plot with the lowest tree density, sapling recruitment was estimated as 378 new individuals·ha–1·year–1. Saplings were aggregated at all spatial scales, whereas trees showed a random pattern of stem distribution. A significant tendency to separation between saplings and trees was observed. The specific stand dynamics observed in balsam fir are connected to an abundant advance regeneration and an age-dependent competition for resources in a heterogeneous environment with different levels of resource availability.

CONTACT AND RESIDUAL EFFECT OF LOW-VOLUME DOSAGES OF PHOSPHAMIDON TO CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) ON TWO SPECIES OF CONIFERS

1972 ◽  
Vol 104 (7) ◽  
pp. 1051-1054
Author(s):  
J. F. Stewart ◽  
N. R. Brown
Keyword(s):  
Statistical Difference ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Residual Effect ◽  
Spruce Budworm ◽  
Picea Rubens ◽  
Fourth Instar ◽  
Red Spruce ◽  
Balsam Fir ◽  
Low Volume

AbstractA series of low-volume spray treatments were conducted to study the contact and residual effect of two concentrations of the insecticide phosphamidon to fourth instar spruce budworm, Choristoneura fumiferana (Clem.), on balsam fir, Abies balsamea (L.) Mill, and red spruce, Picea rubens Sarg. Treatment of sprayed larvae on sprayed trees, unsprayed larvae on sprayed trees, and sprayed larvae on unsprayed trees, resulted in two principal conclusions: (a) Higher concentrations of phosphamidon (1% versus 0.5% active) accelerated mortality in all instances and (b) no statistical difference (P = 0.1%) was found in the final mortalities between treatments in which only the foliage was treated and where both larvae and foliage were treated with phosphamidon.

Sign in / Sign up

Export Citation Format

Share Document