Influence of Stand Factors on Survival of Early Instar Spruce Budworm 1

1979 ◽  
Vol 8 (6) ◽  
pp. 993-996 ◽  
Author(s):  
W. P. Kemp ◽  
G. A. Simmons
Keyword(s):  
1993 ◽  
Vol 125 (3) ◽  
pp. 479-488 ◽  
Author(s):  
Beresford L. Cadogan ◽  
Roger D. Scharbach

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.


2020 ◽  
Vol 463 ◽  
pp. 118035
Author(s):  
Bo Zhang ◽  
David A. MacLean ◽  
Rob C. Johns ◽  
Eldon S. Eveleigh ◽  
Sara Edwards

1985 ◽  
Vol 63 (6) ◽  
pp. 1330-1338 ◽  
Author(s):  
Norman G. Reichenbach ◽  
Gordon R. Stairs

Energetic components (respiration, consumption, frass production, and growth) for larvae of the western spruce budworm (WSB), Choristoneura occidentalis, were modeled using multiple regression techniques for a range of temperatures (10–31 °C) and body weights (5–200 mg). These functions were used in a simulation of the bioenergetics of the WSB under different variable temperature regimes (average temperatures ranging from 10 to 22 °C). Simulation results showed that production increased as temperature increased. Net production efficiencies remained high (maximum ca. 32%) for all temperature regimes save the lowest, in which the maximum net production efficiency (production/assimilation) was 16%. Final assimilation efficiencies ranged from 50 to 52%. Early instar larvae had low total respiration costs, high assimilation efficiencies, low consumption rates, and rapid rates of tissue production. As the larvae increased in size, consumption rates increased, assimilation efficiencies declined, yet the total amount of energy assimilated increased so that production continued. Population energetics of the larvae showed that WSB were similar to other herbivorous ectotherms. Relative to endotherms, ectotherm populations consume similar quantities of energy and exist at higher biomasses per unit area.


1992 ◽  
Vol 124 (6) ◽  
pp. 1085-1092 ◽  
Author(s):  
V.G. Nealis ◽  
K. van Frankenhuyzen ◽  
B.L. Cadogan

AbstractField trials in northern Ontario in 1990 and 1991 confirmed that survival of spruce budworm larvae [Choristoneurafumiferana (Clemens)] (Lepidoptera: Tortricidae) parasitized by Apanteles fumiferanae Viereck (Hymenoptera: Braconidae) was greater than survival of nonparasitized budworm larvae following application of Bacillus thuringiensis var. kurstaki Berliner (Bt). Apparent parasitism by A. fumiferanae increased slightly when application of Bt was early (instar III or IV) but increased significantly when applications were later in the season (instars IV–VI). Delaying the timing of the spray conserved parasitoids while providing significant reductions in budworm densities and not compromising the primary objective of Bt application, i.e. the protection of current year foliage. The potential for long-term management of spruce budworm through the strategic integration of natural and imposed mortalities is discussed.


2007 ◽  
Vol 63 (8) ◽  
pp. 730-736 ◽  
Author(s):  
Daniel Doucet ◽  
Caroline Frisco ◽  
Michel Cusson ◽  
Éric Bauce ◽  
Subba Reddy Palli ◽  
...  

1983 ◽  
Vol 115 (11) ◽  
pp. 1523-1527 ◽  
Author(s):  
E. J. Dobesberger ◽  
K. P. Lim

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.


2002 ◽  
Vol 20 (3) ◽  
pp. 138-142
Author(s):  
William E. Klingeman

Abstract The bagworm (Thyridopteryx ephemeraeformis (Haworth)) is a polyphagous, native pest of numerous deciduous and evergreen ornamental plants. Bagworm larvae were used to investigate host plant susceptibility among ten species and cultivars of maples that are economically important and commonly encountered in landscapes in the eastern United States. Data analyses from 48-hour choice assays, conducted in the laboratory during 2000 and 2001, indicated that differences existed among maples for bagworm feeding preferences and host plant susceptibility. Results from the 48-hour trials were not as accurate as seasonal no-choice assays, however. No-choice assays during both seasons quantified resistance among maples that limited larval bagworm survival and development. Measurements of larval feeding injury demonstrated resistance in paperbark maple (Acer griseum (Franch.) Pax) and trident maple (A. buergerianum Miq.) when compared with other maples. Laboratory results were corroborated during 2001 by a no-choice field assay, in which early instar bagworm larvae performed well on the majority of maples. In contrast, paperbark maple and trident maple were resistant to bagworm feeding, while ‘Autumn Blaze’ Freeman maple (A. x freemanii E. Murray), a hybrid cross obtained by breeding A. rubrum with A. saccharinum, showed moderate resistance.


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