scholarly journals AERIAL APPLICATION OF INSECTICIDES AND THE SUPPRESSION OF INCIPIENT SPRUCE BUDWORM OUTBREAKS

1961 ◽  
Vol 37 (3) ◽  
pp. 203-210 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Early Treatment ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Balsam Fir ◽  
Wind Dispersal ◽  
Spray Application ◽  
Aerial Application

The aerial application of insecticides against spruce budworm outbreaks is now a common practice. The measure had always been applied in outbreaks covering more or less extensive areas until 1960 when an opportunity was provided of spraying a small incipient infestation in the Lower St. Lawrence region of the Province of Quebec. It was hoped that early treatment might suppress the infestation and prevent its spread. Although the operation was successful in greatly reducing insect numbers in the area treated, it failed to arrest the infestation. Wind dispersal of first- and second-instar larvae prior to spray application resulted in the spread of the infestation beyond the area delimited for treatment. Also, the warm and dry weather in the spring of 1960, and the abundance of staminate flowers on the balsam fir and spruce trees greatly favoured larval survival. The aerial application of insecticides as a method of suppressing incipient spruce budworm outbreaks is discussed in the light of these results.

scholarly journals A RECENT SPRUCE BUDWORM OUTBREAK IN THE LOWER ST. LAWRENCE AND GASPE PENINSULA WITH REFERENCE TO AERIAL SPRAYING OPERATIONS

1960 ◽  
Vol 36 (3) ◽  
pp. 209-224 ◽  
Author(s):  
J. R. Blais ◽  
R. Martineau
Keyword(s):  
Spruce Budworm ◽  
Balsam Fir ◽  
Spray Application ◽  
Natural Control ◽  
Insect Abundance ◽  
Factors Associated ◽  
Control Factors ◽  
Aerial Spraying ◽  
Eventual Collapse ◽  
Gaspe Peninsula

The main topics discussed in this paper are: the progress of the spruce budworm outbreak in the Lower St. Lawrence - Gaspé regions from 1949 to 1956; the areas sprayed between 1954 and 1958; timing of spray application in relation to insect abundance and development; effects of treatment on spruce budworm populations and on defoliation of balsam fir; results of aerial defoliation surveys and egg surveys; estimated amounts of wood destroyed by the insect, and losses averted through spraying; the various natural control factors associated with the decline and the eventual collapse of the outbreak.

Effect of fertilization of balsam fir trees on spruce budworm nutrition and development

1978 ◽  
Vol 8 (4) ◽  
pp. 364-374 ◽  
Author(s):  
G. G. Shaw ◽  
C. H. A. Little ◽  
D. J. Durzan
Keyword(s):  
Ammonium Acetate ◽  
Nitrogen Concentration ◽  
Calcium Nitrate ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Balsam Fir ◽  
Pupal Weight ◽  
High Nitrogen ◽  
High Potassium ◽  
Terminal Shoot

Spruce budworm (Choristoneurafumiferana Clem.) larvae were reared on field-grown balsam fir (Abiesbalsamea (L.) Mill.) trees variously treated with nitrogen, potassium, and phosphorous fertilizers. Treatment with high nitrogen had a significant effect on terminal shoot growth, the caloric value, the concentrations of total sugar, starch, crude fat, nitrogen, chlorophyll, and moisture, and the calories per milligram protein in maturing current-year needles, the budworm's food. Concomitantly, high nitrogen increased male and female pupal weight. Ammonium acetate had less effect than urea or calcium nitrate on both tree and budworm responses, and low urea had less effect than high urea. High potassium, particularly in the presence of low urea, negatively affected some tree and budworm responses. Larval survival was increased only by calcium nitrate application. Of all the foliar parameters, the calories per milligram protein and the nitrogen concentration were best correlated with pupal weight. Female pupal weight was positively correlated with number of F1 larvae per female moth. The results support the hypothesis that food quality can significantly affect budworm population dynamics.

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.

SIMULATING AERIAL SPRAYS FOR THE WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE): EVALUATION OF TECHNIQUE AND TWO CANDIDATE INSECTICIDES

1981 ◽  
Vol 113 (9) ◽  
pp. 819-825 ◽  
Author(s):  
Charles E. Richmond
Keyword(s):  
Spruce Budworm ◽  
Spray Application ◽  
Western Spruce Budworm ◽  
Aerial Application ◽  
Application System ◽  
Subalpine Fir ◽  
Preliminary Information ◽  
Population Reduction ◽  
Aerial Sprays ◽  
Deposit Characteristics

AbstractA new spray application system which mimics the spray deposit of aerial applications of chemical insecticides was developed and tested using acephate at the rate of 60 g a.i./L (U.S. Environmental Protection Act registered dosage) on small Douglas-fir and subalpine fir trees infested with western spruce budworm. The system successfully duplicated aerial application by causing a budworm population reduction equivalent to previous aerial tests having analogous insecticide deposit characteristics. Using the system, preliminary information was gained on the effectiveness of sulprofos and thiodicarb. When delivered at a rate of 4.1 L/ha, sulprofos caused a budworm population reduction of 86.2% at 22.4 g a.i./L and thiodicarb caused a reduction of 98% at 45 g a.i./L.

MORTALITY, FEEDING INHIBITION, AND RECOVERY OF SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) LARVAE FOLLOWING AERIAL APPLICATION OF A HIGH-POTENCY FORMULATION OF BACILLUS THURINGIENSIS SUBSP. KURSTAKI

2000 ◽  
Vol 132 (4) ◽  
pp. 505-518 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Carl Nystrom ◽  
John Dedes ◽  
Vern Seligy
Keyword(s):  
Bacillus Thuringiensis ◽  
Spray Deposition ◽  
Larval Mortality ◽  
Lethal Dose ◽  
Spruce Budworm ◽  
Limiting Factor ◽  
Larval Feeding ◽  
Spray Application ◽  
Aerial Application ◽  
Feeding Inhibition

AbstractA larval population of spruce budworm, Choristoneura fumiferana (Clemens), was monitored for 5 d following aerial application of a commercial formulation of Bacillus thuringiensis Berliner subsp. kurstaki to investigate dose acquisition and expression (larval mortality, recovery, feeding, and growth) in relation to spray deposition and persistence of spray deposits. The main objective was to test if previous laboratory observations on how B. thuringiensis affects feeding and dose ingestion by spruce budworm larvae hold true under field conditions. About 40% of the treated population ingested a lethal dose within 1 d after spray application. Lethally dosed larvae died without further feeding upon transfer from treated foliage to (untreated) artificial diet. Resumption of feeding by larvae that survived the treatment was delayed relative to larvae from the control population during 3 d following spray application; during that time, normal feeding activity and larval weight gain were suppressed. Inhibited feeding by survivors appeared to prevent further dose uptake because the proportion of lethally dosed larvae in daily collections did not increase despite significant residual spray deposits in budworm feeding sites. Restoration of "normal" recovery times by the fourth day coincided with a 65–85% reduction in persistence of the pathogen on the foliage and did not result in further lethal dose acquisition, as treatment-induced mortality dropped to about 20% on the 4th and 5th days. The observations are consistent with previous laboratory observations of how B. thuringiensis affects larval feeding and with the hypothesis that feeding inhibition may be a limiting factor in the acquisition of a lethal dose.

Defining the window of opportunity for feeding initiation by second-instar spruce budworm larvae

2018 ◽  
Vol 48 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Alvaro Fuentealba ◽  
Solène Sagne ◽  
Deepa Pureswaran ◽  
Éric Bauce ◽  
Emma Despland
Keyword(s):  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Larval Growth ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Balsam Fir ◽  
Good Survival ◽  
Window Of Opportunity ◽  
Phenological Synchrony

Establishing feeding sites is critical for the survival of neonate Lepidoptera larvae. Rapid foliar quality changes during leaf expansion create a narrow window of opportunity for establishment of early-spring feeders. We examined the effect of phenological synchrony between black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) and balsam fir (Abies balsamea (L.) Mill.) budbreak and spruce budworm (Choristoneura fumiferana (Clemens)) emergence on the feeding behaviour of young larvae and on overall larval growth and survival under laboratory conditions. We correlated these variables with bud development and foliar toughness during the growing season. Our results show that early-emerging second-instar larvae were unable to feed on either black spruce or balsam fir buds; budworm on balsam fir mined old foliage and exhibited good survival and performance, but those on black spruce remained on the foliar surface and suffered high mortality and low growth. In the second later-emerging cohort, bud feeding gradually increased on black spruce whereas it was already the predominant behaviour on balsam fir, and no differences in performance were observed between host species. Thus, black spruce budbreak constitutes a strict window of opportunity, since larvae are often unable to mine the old foliage. Our results suggest that mechanical toughness could be the obstacle preventing young larvae from mining old black spruce needles. Our findings confirm the importance of second-instar ecology in spruce budworm, suggesting that, if climate warming eventually results in an improvement in phenological synchrony between spruce budworm and black spruce, larval survival may increase.

Rate of defoliation of balsam fir in relation to spruce budworm attack and timing of spray application

1979 ◽  
Vol 9 (3) ◽  
pp. 354-361 ◽  
Author(s):  
J. Robert Blais
Keyword(s):  
Feeding Behaviour ◽  
Spruce Budworm ◽  
Early Spring ◽  
Fourth Instar ◽  
Balsam Fir ◽  
Larval Feeding ◽  
Progressive Damage ◽  
Spray Application ◽  
The Relationship ◽  
Very High

Studies were conducted in 1976 and 1977 to determine feeding behaviour and progressive damage to balsam fir (Abiesbalsamea (L.) Mill.) throughout the larval feeding period of the spruce budworm (Choristoneurafumiferana Clem.).Four plots had high populations of approximately 30 larvae and four had very high populations of over 100 larvae per 45-cm branch tip at peak L2. In early spring emerging second-instar larvae mined needles of old foliage; few buds were attacked prior to third instar. Defoliation of current year's growth was between 70 and 80% in plots with high populations and close to 100% in those with very high populations. In the high-population plots the 25% level of foliage destruction occurred close to peak fifth instar and the 50% level just before peak sixth instar. In plots with very high populations 25% defoliation occurred close to peak third instar and 50% defoliation close to peak fourth instar. The relationship between defoliation patterns and best timing of insecticide application is discussed.

scholarly journals Predicting balsam fir mortality in boreal stands affected by spruce budworm

2021 ◽  
Vol 496 ◽  
pp. 119408
Author(s):  
Djidjoho Julien Houndode ◽  
Cornelia Krause ◽  
Hubert Morin
Keyword(s):  
Spruce Budworm ◽  
Balsam Fir

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.

The influence of hardwood content on balsam fir defoliation by spruce budworm

1996 ◽  
Vol 26 (9) ◽  
pp. 1620-1628 ◽  
Author(s):  
Qiong Su ◽  
Ted D. Needham ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Natural Enemies ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Generalized Model ◽  
Stand Management ◽  
Working Hypothesis ◽  
Model Combining

Changing stand composition by increasing hardwood content has been suggested as a long-term method for reducing susceptibility and vulnerability of balsam fir (Abiesbalsamea (L.) Mill.) to spruce budworm (Choristoneurafumiferana (Clem.)). Twenty-five mixed balsam fir–hardwood stands were selected in northern New Brunswick, with five stands in each 20% hardwood class (0–20, 21–40%, etc.). Defoliation each year from 1989 to 1993 was significantly (p < 0.0001) related to hardwood content, with r2 ranging from 0.57 to 0.81. As hardwood content increased, defoliation of balsam fir decreased. From 1989 to 1992, the years of moderate to severe defoliation, balsam fir stands with <40% hardwoods sustained 58–71% defoliation, on average, versus 12–15% defoliation in stands with >80% hardwood. A generalized model combining hardwood content and the estimated defoliation in pure softwood stands in a given year explained 77% of the variation in defoliation over stands and years. This study indicated that mixed balsam fir–hardwood stand management, with hardwood content >40%, could substantially reduce losses during spruce budworm outbreaks. Further research is warranted to elucidate the mechanism involved, but our working hypothesis is that greater hardwood content increased the diversity or populations of natural enemies such as birds and parasitoids.

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