SEPARATING EARLY LARVAE OF SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) AND SPRUCE CONEWORM, DIORYCTRIA RENICULLELOIDES (LEPIDOPTERA: PYRALIDAE) IN SURVEYS OF OVERWINTERING LARVAE

1985 ◽  
Vol 117 (2) ◽  
pp. 261-263 ◽  
Author(s):  
Charles J. Spies III ◽  
J. B. Dimond

The spruce coneworm, Dioryctria reniculleloides (Mut. and Mun.), is often associated with the spruce budworm on spruce host trees and sometimes approaches or equals the spruce budworm, Choristoneura fumiferana (Clem.), in numbers (Spies and Dimond 1985). The coneworn is probably~responsiblefo r some of the damage on spruce attributed to the budworm, and with much balsam fir in eastern North America now dead from defoliation or harvested, there is increasing interest in spruce as the major resource to protect.

1999 ◽  
Vol 131 (6) ◽  
pp. 725-727 ◽  
Author(s):  
André J. Forté ◽  
Claude Guertin ◽  
Jean Cabana

The spruce budworm Choristoneura fumiferana (Clem.) is the most damaging insect of the balsam fir Abies balsema (L.) Mill. (Pinaceae) and the white spruce Picea glauca (Moench) Voss (Pinaceae) throughout eastern North America. In outbreak conditions, close to 100% tree mortality can occur in untreated mature fir stands (MacLean 1980). Bacillus thuringiensis var. kurstaki (Bacillaceae) is currently used to reduce spruce budworm damage (Van Frankenhuyzen and Payne 1993). Other possible biological control agents, such as baculoviruses, are also investigated to complement the use of B. thuringiensis. Baculoviruses are advantageous because they occur naturally in several insect species and are generally host specific (Federici 1993).


1984 ◽  
Vol 60 (1) ◽  
pp. 10-14 ◽  
Author(s):  
J. T. Basham

Far more investigations of the deterioration and utilization of the stems of trees killed following spruce budworm (Choristoneura fumiferana [Clem.]) defoliation have been, or are being, carried out during the current budworm outbreak in eastern and central North America than in all previous outbreaks combined. Unfortunately the results are dispersed in a wide variety of publications, some of which are relatively obscure and difficult to find. This report is an attempt to assist the forest manager faced with salvage decisions, by reviewing and summarizing current knowledge and by identifying some of the potentially useful literature. Key words: Spruce budworm, balsam fir, stem deterioration, sap rot, dead trees, salvage, utilization, pulp quality.


1950 ◽  
Vol 28d (6) ◽  
pp. 308-331 ◽  
Author(s):  
W. G. Wellington ◽  
J. J. Fettes ◽  
R. M. Belyea ◽  
K. B. Turner

Biological and meteorological records were examined for periods when outbreaks of the spruce budworm, Choristoneura fumiferana (Clem.), were known to have occurred in northeastern North America. The survey showed that the following significant events occurred during the period of three to four years preceding an outbreak. Decreasing annual numbers of low pressure centers passed over the area in which the outbreak later occurred. Therefore, the outbreak began at a time of decreased or minimal storminess. Drought occurred, chiefly in June and July, but also occasionally in spring and autumn. Annual increments of host trees on dry sites declined. Outbreaks of the forest tent caterpillar, Malacosoma disstria Hbn., occurred, particularly in Ontario. These events, in aggregate, occurred so consistently before spruce budworm outbreaks that they have future predictive value. In addition, they reinforce some suggestions made by earlier authors and suggest modifications of hypotheses concerning the behavior of developing populations of the spruce budworm.


1989 ◽  
Vol 121 (3) ◽  
pp. 267-281 ◽  
Author(s):  
Jacques Régnière ◽  
Timothy J. Lysyk ◽  
Michel Auger

AbstractThe 45-cm mid-crown branch tip from balsam fir and white spruce is described in terms of surface area, fresh weight, and bud density. Fresh weight is suggested as the most appropriate unit to express density of all stages of the spruce budworm’s, Choristoneura fumiferana (Clem.), life cycle, particularly for the purposes of comparisons between host species and locations with different foliage conditions.Changes in distribution of the spruce budworm in the crown of balsam fir are documented for all stages of the insect’s life cycle. Correction factors to account for these changes when estimating density on the basis of the 45-cm branch tip sampling unit are given for balsam fir and white spruce.The amount of error in detection of spruce budworm larvae on foliage of both host trees by sampling personnel varied systematically and consistently as a function of insect development. A method to compensate for this type of error is also suggested.


1952 ◽  
Vol 84 (11) ◽  
pp. 325-335 ◽  
Author(s):  
R. M. Belyea

One of the problems arising from severe outbreaks of the spruce budworm, Choristoneura fumiferana (Clem.), is the evaluation of the factors contributing to the decline of the host trees. An intensive study of the death and deterioration of balsam fir, Abies balsamea (L.) Mill., was carried out from 1946 to 1951 in the area southwest of Lake Nipigon in northwestern Ontario, where a severe spruce budworm outbreak was in progress.


1961 ◽  
Vol 93 (2) ◽  
pp. 118-123 ◽  
Author(s):  
J. G. Pilon ◽  
J. R. Blais

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.


1986 ◽  
Vol 62 (2) ◽  
pp. 96-100 ◽  
Author(s):  
D. J. McRae

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.


1977 ◽  
Vol 109 (9) ◽  
pp. 1239-1248 ◽  
Author(s):  
O. N. Morris

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.


1990 ◽  
Vol 122 (6) ◽  
pp. 1271-1272 ◽  
Author(s):  
Hemendra Mulye ◽  
Roger Gordon

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.


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