RELATIONSHIPS BETWEEN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) EGG MASS DENSITY AND RESULTANT DEFOLIATION OF BALSAM FIR AND WHITE SPRUCE

1990 ◽  
Vol 122 (2) ◽  
pp. 253-262 ◽  
Author(s):  
T.J. Lysyk
Keyword(s):  
Logistic Regression ◽  
Mass Density ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Population Trends ◽  
Balsam Fir ◽  
Egg Mass ◽  
Regression Equations ◽  
Regional Population

AbstractAnnual spruce budworm, Choristoneura fumiferana (Clemens), survey data were subjected to multiple and logistic regression analyses to examine the relationship between egg mass density in the fall and resultant defoliation the next season. Egg mass density was the most important variable associated with resultant defoliation, followed by current defoliation, regional population trends, host species, and sprays. Together, these accounted for 60% of the variation in resultant defoliation. Balsam fir [Abies balsamea (L.) Miller] suffered greater levels of defoliation than white spruce [Picea glauca (Moench) Voss] at a given egg mass density. Resultant defoliation of balsam fir also showed a steeper response to egg mass density than resultant defoliation of white spruce. Levels of current defoliation increased susceptibility to defoliation in a similar manner between species, as did regional population trends. Sprays were more effective at reducing resultant defoliation on balsam fir than on white spruce but, overall, did not confer a high level of foliage protection. Predictions of resultant defoliation using the multiple regression models had confidence limits averaging 75%, which are too large to be useful for predictive purposes. The logistic regression equations could be used to predict the probability of a stand receiving light or severe defoliation.

A 2-YEAR STUDY OF VIRUS – CHEMICAL INSECTICIDE COMBINATION IN THE INTEGRATED CONTROL OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (TORTRICIDAE: LEPIDOPTERA)

1974 ◽  
Vol 106 (8) ◽  
pp. 813-824 ◽  
Author(s):  
O. N. Morris ◽  
J. A. Armstrong ◽  
G. M. Howse ◽  
J. C. Cunningham
Keyword(s):  
Choristoneura Fumiferana ◽  
Mass Density ◽  
Integrated Control ◽  
Larval Mortality ◽  
Spruce Budworm ◽  
Ground Level ◽  
White Spruce ◽  
Balsam Fir ◽  
Egg Mass ◽  
Chemical Insecticide

AbstractDuring 1972, spruce budworm infested white spruce and balsam fir trees were sprayed aerially with a low dose of fenitrothion (0.25 oz AI/ac), entomopox virus (EPV) at 7.6 × 1010 polyhedra/ac, nuclear polyhedrosis virus (NPV) at 2.7 × 1011 polyhedra/ac, or each virus–fenitrothion combination. Fenitrothion (active ingredient), NPV, and EPV deposited at ground level at 5%, 31%, and 42%, respectively, of the amounts emitted.In the year of application, NPV + fenitrothion was highly effective in population reduction and foliage protection especially on; balsam fir although a higher virus infection rate was found on white spruce than on balsam fir. EPV + fenitrothion also provided a high level of foliage protection and apparently reduced surviving female:male sex ratio to 1:2 compared with the normal 1:1 ratio. NPV + insecticide caused highest larval mortality, highest incidence of virus, lowest rate of moth emergence, fewest progeny, and lowest rate of progeny survival. The natural incidence of microsporidia was low in all plots.In the year following application, the NPV + insecticide treated plot again showed lowest population density, highest larval mortality and incidence of virus, and low defoliation and egg mass density. However, there was a higher proportion of viable eggs deposited than in the previous year. Egg parasitism by Trichogramma minutum increased by 1.5 to 4.2% in plots treated with virus only and declined by 1.6 to 10.5% in insecticide treated plots and by 1.2% in untreated check plot. The transmission of the virus from one year to the next is considered to be of paramount importance in the future use of this pathogen in spruce budworm control.

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.

Incidence and impact of Entomophaga aulicae (Zygomycetes: Entomophthorales) and a nucleopolyhedrovirus in an outbreak of the whitemarked tussock moth (Lepidoptera: Lymantriidae)

2002 ◽  
Vol 134 (6) ◽  
pp. 825-845 ◽  
Author(s):  
K. van Frankenhuyzen ◽  
P. Ebling ◽  
G. Thurston ◽  
C. Lucarotti ◽  
T. Royama ◽  
...  
Keyword(s):  
Mass Density ◽  
Abies Balsamea ◽  
Larval Survival ◽  
Balsam Fir ◽  
Egg Mass ◽  
Population Changes ◽  
Tussock Moth ◽  
Orgyia Leucostigma ◽  
Recent Outbreak ◽  
Whitemarked Tussock Moth

AbstractIn Nova Scotia, the whitemarked tussock moth, Orgyia leucostigma Fitch, periodically erupts in outbreaks that typically last 3–5 years. Population changes during a recent outbreak were monitored by means of aerial defoliation surveys and fall egg-mass surveys that were conducted between 1997 and 2001. Severe defoliation was first recorded on approximately 250 ha in 1996. The defoliated area increased rapidly to hundreds of thousands hectares in 1998, after which it sharply declined to about 4700 ha in 2000 and 0 ha in 2001. The total infested area [>0.01 egg masses per three branches of Abies balsamea L. (Pinaceae)] decreased from about 1.4 million ha in 1997 to about 13 500 ha in 2001. Between 1996 and 2001, the infestation involved a cumulative total of 2.4 million ha, covering most of the province. The collapse of larval populations during 1998 was associated with widespread prevalence of a singly embedded nucleopolyhedrovirus (NPV) and Entomophaga aulicae (Reichardt in Bail) Humber (Zygomycetes: Entomophthorales). Sampling of larval populations in late July and August 1998 revealed a widespread and virtually sympatric occurrence of those pathogens in areas that were under defoliation pressure, with infection levels by each pathogen exceeding 75% in many sample sites. Pathogen impacts on larval survival were studied in 1999 in a persisting pocket of severe infestation in Hants County. Larvae were collected every 3 d from balsam fir branch samples between 17 June and 21 July and reared to determine cause of death. The two pathogens together accounted for at least 50% of cohort mortality, calculated as marginal mortality rates according to Royama (2001). Although cohort mortality due to disease on balsam fir was significantly correlated with between-generation reduction in mean egg-mass density, overall pathogen-induced mortality was not high enough to drive the populations into an endemic state, and a moderate infestation persisted into 2000.

Variations in the foliar amino acid composition of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) in relation to outbreaks of the spruce budworm (Choristoneura fumiferana (Clem))

1971 ◽  
Vol 49 (7) ◽  
pp. 1005-1011 ◽  
Author(s):  
J. P. Kimmins
Keyword(s):  
Amino Acids ◽  
Picea Glauca ◽  
Host Plants ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Apparent Correlation

The amino acids of new and old foliage of flowering and non-flowering balsam fir (Abies balsamea (L.) Mill.) and white spruce (Picea glauca (Moench) Voss) were investigated using two-dimensional descending paper chromatography. The data were analyzed for variation associated with age of foliage, age of tree, and flowering condition. The concentration of foliar amino acids was greater in balsam fir than in white spruce, and greater in new foliage than old foliage.The difference in concentration between foliage of flowering and non-flowering trees was smaller. However, the new foliage of flowering fir had higher levels of most of the amino acids examined than any other foliage category. This appears to reflect the known suitability of these foliage categories for spruce budworm larvae. While the data presented do not quantify the ecological significance of this apparent correlation, they do support the theory that variations in the nutritional quality of host plants play a very important role in the dynamics of herbivore populations.

scholarly journals EFFECTS OF DEFOLIATION BY SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA CLEM.) ON RADIAL GROWTH AT BREAST HEIGHT OF BALSAM FIR (ABIES BALSAMEA (L.) MILL.) AND WHITE SPRUCE (PICEA GLAUCA (MOENCH) VOSS.)

1958 ◽  
Vol 34 (1) ◽  
pp. 39-47 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Picea Glauca ◽  
Radial Growth ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
First Year ◽  
Growth Ratio ◽  
Breast Height

The relationship between spruce budworm defoliation and radial growth at breast height for balsam fir and white spruce trees of merchantable size was studied in various stands in northwestern Ontario. Defoliation was recorded yearly for these stands from the beginning of the infestation, and radial growth measurements were obtained from increment cores. The first year of radial growth suppression was calculated by comparing the growth of the affected species with that of jack pine and red pine trees by means of a growth-ratio technique. Apparent suppression in balsam fir and white spruce varied between stands, and, generally, occurred at the earliest in the second year and at the latest in the fourth year of severe defoliation. A wide ring at the base of the tree coinciding with the first year of suppression as reported by Craighead was non-existent.

Insect–host relationships influencing disturbance by the spruce budworm in a boreal mixedwood forest

2004 ◽  
Vol 34 (9) ◽  
pp. 1870-1882 ◽  
Author(s):  
V G Nealis ◽  
J Régnière
Keyword(s):  
Life Cycle ◽  
Populus Tremuloides ◽  
Black Spruce ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Host Tree ◽  
Balsam Fir ◽  
Insect Host ◽  
Boreal Mixedwood Forest

Demographic data from a 15-year outbreak of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae), in a boreal mixedwood forest in Ontario, Canada, are used to interpret stand-level ecological disturbance in terms of susceptibility and vulnerability (mortality) of balsam fir (Abies balsamea (L.) Mill.), white spruce (Picea glauca (Moench) Voss), and black spruce (Picea mariana (Mill.) BSP). All three host-tree species are highly susceptible for oviposition by the spruce budworm and all are suitable for completion of the budworm life cycle. Host-related differences in susceptibility arise from the degree of synchrony between spruce budworm phenology during the feeding stages and host-tree phenology. Spruce budworm density was highest on white spruce throughout the budworm's life cycle and over the course of the outbreak, but more rapid flushing and growth of current-year buds in white spruce reduced damage relative to that on balsam fir. Conversely, later flushing of current-year buds on black spruce led to a reduction in budworm density early in the season and a corresponding reduction in defoliation. The combination of high budworm densities and severe defoliation caused mortality first on balsam fir. By the end of the outbreak, 89% of the balsam fir component >10 cm DBH was eliminated compared with 49% of the white spruce in the same size class. The lower susceptibility of black spruce resulted in survival of all but the smallest size classes of that species. Nonhost species such as trembling aspen (Populus tremuloides Michx.) nearly doubled their basal area during the outbreak. The results link processes inherent in the insect–host relationship with the population ecology of the insect and the disturbance ecology of the forest.

Foliage architecture explains oviposition preference of spruce budworm (Lepidoptera: Tortricidae) for white spruce over balsam fir

2006 ◽  
Vol 138 (2) ◽  
pp. 198-204 ◽  
Author(s):  
Gary G. Grant
Keyword(s):  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Oviposition Preference ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Spatial Arrangement ◽  
Balsam Fir

AbstractI conducted dual-choice oviposition bioassays to test the hypothesis that spruce budworm, Choristoneura fumiferana (Clemens), prefer the foliage architecture (spatial arrangement of foliage needles) of white spruce (Picea glauca (Moench) Voss; Pinaceae) to that of balsam fir (Abies balsamea (L.) P. Mill.; Pinaceae). Needles of white spruce radiate around the twig axis, giving the foliage a round architecture. Needles of balsam fir typically radiate bilaterally from the twig axis, giving the foliage a flat architecture, although on some trees foliage needles radiate around the twig axis, giving the foliage a round architecture. In bioassays, females showed a 2.4:1 preference for white spruce over "flat" balsam fir foliage, but this preference was reduced significantly to a 1.2:1 ratio when balsam fir had a round architecture. Given a choice between "round" and "flat" balsam fir foliage, females preferred the "round" foliage by a 2.2:1 margin. A similar preference for the round architecture was also observed when artificial (plastic) foliage with the two types of needle arrangements were compared. I conclude that the spatial arrangement of foliage needles is a major factor responsible for the oviposition preference of spruce budworm for white spruce over balsam fir.

scholarly journals Forest Succession Following a Spruce Budworm Outbreak in Minnesota

1985 ◽  
Vol 61 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Harold O. Batzer ◽  
Michael P. Popp
Keyword(s):  
Forest Succession ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Basal Area ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir ◽  
Red Maple ◽  
Shrub Species ◽  
Before And After

Plots in 24 spruce-fir stands in northeastern Minnesota studied throughout the period 1957 to 1962 at the time of a spruce budworm outbreak were remeasured in 1979. Composition of the overstory changed from an average of 79% of the basal area in host species before to 31% after the budworm outbreak. Twelve percent of the stands showed growth in nonhost species that more than offset the loss in balsam fir and white spruce. The understory was minimally stocked with balsam fir in two-thirds of the stands. Only 4% of the regeneration was spruce. Even so, some well-established white spruce seedlings were found in two-thirds of the stands. Red maple was the most abundant hardwood invader. Raspberry, hazel and mountain maple were the principal shrub species limiting balsam fir reproduction Shrubs were most abundant in stands where balsam fir mortality had exceeded 80%. Half of the stands had seedlings that originated both before and after the outbreak; 45% had seedlings that originated only after the outbreak; and 5% had seedlings that originated only before the outbreak. Stands having moderate mixture of nonhost species in the over-story prior to the budworm outbreak had the most balsam fir regeneration. This resulted from seed produced by surviving balsam fir trees after the outbreak. Key words: Choristoneura fumiferana, Abies balsamea, Balsam fir, spruce-fir shrubs

Interactions among defoliation level, species, and soil richness determine foliage production during and after simulated spruce budworm attack

2020 ◽  
Vol 50 (6) ◽  
pp. 565-580
Author(s):  
Yuanyuan Wu ◽  
David A. MacLean ◽  
Chris Hennigar ◽  
Anthony R. Taylor
Keyword(s):  
Picea Glauca ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Shoot Length ◽  
Balsam Fir ◽  
Site Quality ◽  
Number Of Shoots

Defoliation level and site type are thought to influence tree response during spruce budworm (Choristoneura fumiferana (Clemens)) outbreaks. We determined the effects of four manual defoliation treatments (0%, 50%, 100%, and 100% + bud removal of current foliage) for 3 years on foliage production of balsam fir (Abies balsamea (L.) Mill.), black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.), and white spruce (Picea glauca (Moench) Voss) trees on four site-quality classes. After 3 years of defoliation and 2 years of recovery, foliage biomass was reduced by 34%–98%. During defoliation, the number of shoots generally increased and shoot length of spruce generally decreased, especially on rich sites. During recovery, the number of shoots increased substantially, shoot length decreased, and bud destruction reduced the number of shoots by about 50% compared with that of trees that received the 100% defoliation treatment. Defoliation did not substantially affect needle length. Trees on rich sites had two- to fourfold greater foliage production than trees on poor sites. Effects of site and defoliation differed among species, but site quality, especially nutrition, played an important role in production of shoots and needles and the tree’s ability to withstand defoliation. Black spruce had more limited ability to recover foliage biomass, only producing more shoots, whereas balsam fir and white spruce had stronger ability to recover needle and shoot length, respectively.

EFFICACY AND FIELD PERSISTENCE OF BACILLUS THURINGIENSIS AFTER GROUND APPLICATION TO BALSAM FIR AND WHITE SPRUCE IN WISCONSIN

1984 ◽  
Vol 116 (2) ◽  
pp. 153-158 ◽  
Author(s):  
R. C. Reardon ◽  
K. Haissig
Keyword(s):  
Bacillus Thuringiensis ◽  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
White Spruce ◽  
Balsam Fir

AbstractBacillus thuringiensis was applied at three dosages (1.0 BIU/tree, 0.1 BIU/tree, and.01 BIU/tree) to balsam fir, Abies balsamea (L.) Mill., and white spruce, Picea glauca (Moench) Voss, with mist blowers. Crystalline proteins were detected on balsam fir foliage for a maximum of 16 days (d) after B. thuringiensis was applied at 1.0 BIU/tree. Higher levels of crystalline proteins were detected on white spruce foliage treated with Thuricide 16B than on that treated with Dipel 4L. On balsam fir, the situation was the opposite. Mist-blower-treated foliage collected for up to 16 d posttreatment caused mortality of spruce budworm, Choristoneura fumiferana (Clemens), larvae. Viable endospores of B. thuringiensis were recovered on white spruce foliage collected 1 year after treatment.

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