COMPARATIVE OPTIMAL TIMES OF APPLICATION OF BENZOYLPHENYL UREAS TO WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE)

1989 ◽  
Vol 121 (1) ◽  
pp. 75-79 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Susan P. Worner ◽  
Haiganoush K. Preisler
Keyword(s):  
Natural Populations ◽  
Ecological Factors ◽  
Spruce Budworm ◽  
Climatic Conditions ◽  
Optimal Time ◽  
Laboratory Population ◽  
Optimal Timing ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Benzoylphenyl Ureas

AbstractFour benzoylphenyl ureas (BPU’S) were tested on the four feeding larval instars of western spruce budworm, Choristoneura occidentalis Freeman, from a nondiapausing laboratory colony. BPU’s compared were chlorfluazuron, penfluron, triflumuron, and XRD-473 (N-(((3,5-dichloro-4-(1,1,2,2-tetrafluoroethoxy)phenyl-amino)carbonyl)-2, 6-difluorobenzymide). Although previous evidence suggested that BPU’S were generally most active on younger instars, last-instar western spruce budworm larvae were most susceptible to three of the four tested. Contour plots of estimated effectiveness during development of a western spruce budworm laboratory population indicated that the optimal time of application (lowest LC90) for XRD-473 would be ca. 16 days after the first group of larvae hatched, but the optimal time for the other three BPU’s would be between 40 and 50 days after hatch began. However, chronological age of insects in natural populations is difficult to estimate because of the influence of factors such as climatic conditions (e.g. temperature) and other ecological factors. The need to estimate optimal timing for application of BPU’s and other chemicals in terms of physiological time during population development is discussed.

Chemistry and field evaluation of the sex pheromone of western spruce budworm,Choristoneura occidentalis, Freeman

1982 ◽  
Vol 8 (2) ◽  
pp. 339-350 ◽  
Author(s):  
H. T. Cory ◽  
G. E. Daterman ◽  
G. D. Daves ◽  
L. L. Sower ◽  
R. F. Shepherd ◽  
...  
Keyword(s):  
Sex Pheromone ◽  
Spruce Budworm ◽  
Field Evaluation ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm

RELATIONSHIPS BETWEEN ATTACK RATES AND SURVIVAL OF WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE), AND BUD DEVELOPMENT OF DOUGLAS-FIR, PSEUDOTSUGA MENZIESII (MIRB.) FRANCO

1992 ◽  
Vol 124 (2) ◽  
pp. 347-358 ◽  
Author(s):  
Roy F. Shepherd
Keyword(s):  
Close Association ◽  
Spruce Budworm ◽  
Larval Survival ◽  
Douglas Fir ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Bud Development ◽  
Feeding Sites ◽  
Vegetative Buds ◽  
Wide Range

AbstractIndividual larvae of western spruce budworm (Choristoneura occidentalis Freeman) were observed from overwintering emergence to pupation at six locations spread over a wide range of altitudes and thus climate. A weekly census of 100 lower-crown buds per plot indicated large differences in rates of bud development and larval survival among locations.Emerging second-instar larvae attempted to mine swelling buds of Douglas-fir. If the buds were hard and tight, larvae mined 1-year-old needles until penetrable buds were available. Larvae dispersed over the crowns with only one larva becoming established in each bud; thus, many early-emerging and surplus larvae could not find suitable feeding sites and disappeared. Within the protective bud, survival was high. After buds flushed and larvae became exposed, densities dropped, probably due to increased predation and decreased food quality. Correlations indicated a close association between larval survival for the exposed period between bud flush and pupation, and overall larval survival.Douglas-fir trees responded to initial bud removal, but not to needle removal, by inducing latent buds in the axils of needles to grow into active vegetative buds ready to develop and flush the next spring. The number of these new vegetative buds formed was greatest when the initial buds were removed early in the season before flush, and decreased thereafter. Trees with vigorous crowns had the greatest response to defoliation by inducing the largest number of latent buds into becoming active vegetative buds; these were found mainly on the 2- and 3-year-old internodes.

XRD-473 (AN EXPERIMENTAL BENZOYLPHENYLUREA): RATES AND OPTIMAL TIME OF APPLICATION TO WESTERN SPRUCE BUDWORM1,2

1986 ◽  
Vol 21 (1) ◽  
pp. 16-20
Author(s):  
Jacqueline L. Robertson ◽  
Haiganoush K. Preisler
Keyword(s):  
Spruce Budworm ◽  
Field Testing ◽  
Field Application ◽  
Optimal Time ◽  
Western Spruce Budworm ◽  
Time Of Application ◽  
Application Rates ◽  
Series Of Experiments

XRD-473 (N-(((3,5-Dichloro-4-(1,1,2,2-tetrafluoroethoxy) phenyl-amino) carbonyl)-2, 6-difluorobenzamide), a benzoylphenylurea (BPU), was tested in a series of experiments to estimate the optimal time and rate of application relative to instar distribution of a population of western spruce budworm Choristoneura occidentals Freeman. The optimal time of application was estimated to be the first 17 days after the first group of second instars emerges from diapause. Based on the rainfastness of the chemical, field application rates were estimated to be 3.5, 7.0, and 10.4 g/ha. XRD-473 appears to be more than twice as effective per unit rate than any BPU previously tested; if it becomes commercially available, XRD-473 would be a prime candidate for field testing.

EARLY GROUND APPLICATION OF ACEPHATE FOR CONTROL OF THE WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) ON DOUGLAS-FIR

1977 ◽  
Vol 109 (9) ◽  
pp. 1153-1158 ◽  
Author(s):  
J. Wayne Brewer ◽  
J. O’Neal
Keyword(s):  
Aqueous Solution ◽  
Larval Mortality ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Choristoneura Occidentalis ◽  
Regression Analyses ◽  
Western Spruce Budworm ◽  
Systemic Action ◽  
Equipment Application

AbstractThe insecticide acephate (0.5-dimethyl acetyl phosphoramidothioate) was applied at 0.5, 1.0, and 1.5 lb A.I./gal (.058, 0.118, 0.179 kg/l.) in aqueous solution to individual Douglas-fir trees infested with western spruce budworm, Choristoneura occidentalis Freeman, larvae in central Washington using hand held ground application equipment. Application was made when larvae were in the needle mining – bud mining stage at rates ranging from 2.58 to 5.10 gal/acre (3.97 to 7.84 l./ha). For all three concentrations, mortality of larvae inside needles was 94–98% after 1 day compared with a check mortality of 18% and larval mortality inside buds was 99% after 1 day compared with 23% for the check. Regression analyses indicated that defoliation was positively correlated with the number of needles mined the current year and per cent punctured buds, and negatively correlated with larval mortality inside both needles and buds. The data suggest that when applied at the rates used, acephate has some type of systemic action and can provide foliage protection during the year of application.

IMPLANTATION AND INJECTION OF SYSTEMICS TO SUPPRESS SEED AND CONE INSECTS IN DOUGLAS FIR IN MONTANA,

1985 ◽  
Vol 117 (8) ◽  
pp. 961-969 ◽  
Author(s):  
R.C. Reardon ◽  
L.J. Barrett ◽  
T.W. Koerber ◽  
L.E. Stipe ◽  
J.E. Dewey
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seed Yield ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Systemic Insecticides ◽  
Filled Seeds

AbstractThe systemic insecticides oxydemeton-methyl and acephate were injected at 10- and 15-cm spacings, and acephate and dimethoate were implanted at 10-cm spacing in Douglas fir, Pseudotsuga menziesii var. glauca (Beissn.) Franco, to improve seed yield. Nutrients were also injected at 15-cm spacing. All treatments except nutrients and dimethoate increased the yield of filled seeds when compared with the checks. The western spruce budworm, Choristoneura occidentalis Freeman, and spruce coneworm, Dioryctria reniculelloides Mutuura and Munroe, caused most of the damage to cones.

Effect of artificial diet components on conspecific repellency of larval oral secretions from western spruce budworm (Lepidoptera: Tortricidae)

2011 ◽  
Vol 143 (4) ◽  
pp. 384-387 ◽  
Author(s):  
L.M. Poirier ◽  
J.H. Borden
Keyword(s):  
Fatty Acids ◽  
Wheat Germ ◽  
Artificial Diet ◽  
Linseed Oil ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Oral Secretions ◽  
Insect Gut ◽  
Choice Feeding

AbstractA choice feeding bioassay was used to investigate the effects of artificial diet components on the repellency of larval oral secretions from western spruce budworm, Choristoneura occidentalis Freeman, to conspecific larvae. Oral secretions from insects fed on agar supplemented with linseed oil were as repellent as secretions from insects fed on complete artificial diet. Secretions from insects fed on agar alone, agar and casein, or agar and wheat germ were not significantly more repellent than distilled water; neither was linseed oil alone. Linseed oil consists of glycerides of several fatty acids, which are likely metabolized quickly in the insect gut; repellency of oral secretions could be due to any of the related fatty acids or metabolites.

CONTACT AND FEEDING TOXICITIES OF ACEPHATE AND CARBARYL TO LARVAL STAGES OF THE WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS (LEPIDOPTERA: TORTRICIDAE)

1980 ◽  
Vol 112 (10) ◽  
pp. 1001-1006 ◽  
Author(s):  
Jacqueline L. Robertson
Keyword(s):  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Relative Susceptibility ◽  
Larval Stages

AbstractSpray and feeding bioassays of acephate and carbaryl were conducted with each of the six instars of the western spruce budworm, Choristoneura occidentalis Freeman. Dose-mortality regressions were used to estimate overall relative susceptibility. Small differences in overall susceptibility of the six instars to acephate and large differences to carbaryl were observed. Application of carbaryl so that it would be present when second instars emerge from their hibernacula may maximize efficacy by minimizing the tolerance-instar effect. The efficacy of acephate may be relatively unaffected by instar-related changes in tolerance.

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