THE RELATIONSHIP OF THE SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA, CLEM.) TO THE FLOWERING CONDITION OF BALSAM FIR (ABIES BALSAMEA (L.) MILL.)

1952 ◽  
Vol 30 (1) ◽  
pp. 1-29 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Direct Effect ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Larval Stages ◽  
Competition For Food ◽  
Relationship Of ◽  
The Relationship

Populations of the spruce budworm were studied on flowering and nonflowering balsam fir trees. Generally more eggs were found on the flowering trees. The flowering balsam fir trees were found to harbor higher populations in the early larval stages owing to the presence on these trees of staminate flowers and flower cups. The behavior of the larvae in relation to staminate flowers and flower cups was studied in both the field and the laboratory. Larvae that fed partially on pollen developed more rapidly than larvae that fed exclusively on foliage. Pollen as a food did not appear to have any direct effect on survival or fecundity. Other experiments showed that mortality was higher, development retarded, and fecundity reduced in insects forced to feed on old foliage in contrast with those fed on the current year's growth. Defoliation was more severe on flowering trees in the earlier stages of the infestation. However, as populations increased, wandering increased owing to competition for food. This resulted in an overflow of larvae from flowering to nonflowering trees.

COMPARATIVE EFFICACY OF THURICIDE 16B® AND DIPEL 88® AGAINST THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) IN BALSAM FIR STANDS

1983 ◽  
Vol 115 (8) ◽  
pp. 1001-1006 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Direct Effect ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Comparative Efficacy ◽  
Commercial Formulation ◽  
Water Based ◽  
Pupal Parasitism

AbstractThe effectiveness of Thuricide 16B®, a water-based commercial formulation of Bacillus thuringiensis var. torstaki (B.t.), Dipel 88®, an oil-based formulation, and the Dipel® vehicle (Dipel 88 without B.t.) were compared by aerial applications against the spruce budworm, Choristoneura fumiferana (Clem.) in balsam fir, Abies balsamea (L.) stands. The two B.t. products applied at similar dosage rates were similar in effectiveness and the Dipel vehicle was not toxic for budworm larvae at rates applied Comparisons of populations of parasites made between pre- and post-spray sampling periods and between treated and untreated plots indicated no direct effect of Dipel 88 on the rate of larval and pupal parasitism.

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 THE VULNERABILITY OF BALSAM FIR TO SPRUCE BUDWORM ATTACK IN NORTHWESTERN ONTARIO, WITH SPECIAL REFERENCE TO THE PHYSIOLOGICAL AGE OF THE TREE

1958 ◽  
Vol 34 (4) ◽  
pp. 405-422 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Special Reference ◽  
Tree Mortality ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Site Quality ◽  
Physiological Age ◽  
Northwestern Ontario ◽  
Relationship Of ◽  
The Relationship ◽  
Relative Vulnerability

The annual defoliation by spruce budworm and the progressive mortality of balsam fir trees were recorded in nine study plots in northwestern Ontario over a period of 11 years. In addition to general observations on the relationship of tree mortality to defoliation, some information was obtained on the relative vulnerability of the trees with respect to size, physiological age (flowering condition), and vigor (site quality).

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.

FIELD RESPONSE OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE), TO DOSAGE AND VOLUME RATES OF COMMERCIAL BACILLUS THURINGIENSIS

1984 ◽  
Vol 116 (7) ◽  
pp. 983-990 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Forest Stands ◽  
Effective Application ◽  
Field Response

AbstractThuricide and Dipel, formulations of Bacillus thuringiensis (B.t.), were applied aerially against the spruce budworm, Choristoneura fumiferana (Clem.), in forest stands of balsam fir, Abies balsamea L. A dosage of 30 Billion International Units (BIU) of B.t./ha applied in 2.4 to 4.7 L of spray/ha was most effective. Application of 20 BIU/ha was marginally effective against a population of 12 to 36 larvae/45 cm of branch.

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