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.

EFFECTS OF INSECT GROWTH REGULATORS ON THE WESTERN SPRUCE BUDWORM (CHORISTONEURA OCCIDENTALIS) (LEPIDOPTERA: TORTRICIDAE): II. FECUNDITY AND FERTILITY REDUCTION FOLLOWING LAST INSTAR TREATMENTS

1979 ◽  
Vol 111 (12) ◽  
pp. 1369-1380 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Richard A. Kimball
Keyword(s):  
Simple Model ◽  
Reproductive Factors ◽  
Female Parent ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Insect Growth Regulators ◽  
Fertility Reduction ◽  
Reproductive Effects ◽  
Population Reduction

AbstractThe fecundity and fertility of parent adult western spruce budworm, Choristoneura occidentalis Freeman, which survived treatment with IGRs in their last larval stage was assessed. With few exceptions, IGR treatment significantly reduced both reproductive factors regardless of whether the male or female parent had been treated. A simple model estimating population reduction in the F1-generation based on lethal and reproductive effects on the parents is described. If IGRs were applied at a dosage of 154 g/ha (ca. 2 oz/acre), the estimated percentages of F1 reduction which would result ranged from 74.6 (ZR-515) to 99+ (ZR-512 and Ro 10-3108 (oil)).

LABORATORY AND FIELD EVALUATION OF NEOAPLECTANA CARPOCAPSAE (RHABDITIDA: STEINERNEMATIDAE) AGAINST THE ELM LEAF BEETLE (COLEOPTERA: CHRYSOMELIDAE) AND THE WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1981 ◽  
Vol 113 (9) ◽  
pp. 787-793 ◽  
Author(s):  
Harry K. Kaya ◽  
Arnold H. Hara ◽  
Richard C. Reardon
Keyword(s):  
Spruce Budworm ◽  
Field Evaluation ◽  
Leaf Beetle ◽  
Field Application ◽  
Dispersal Ability ◽  
Choristoneura Occidentalis ◽  
Laboratory Studies ◽  
Western Spruce Budworm ◽  
Elm Leaf Beetle ◽  
Population Reduction

AbstractLaboratory studies showed that elm leaf beetle, Pyrrhalta luteola (Müller), larvae and pupae were susceptible to the nematode Neoaplectana carpocapsae Weiser; adults were less likely to be infected because of their dispersal ability. Spruce budworm, Choristoneura occidentalis Freeman, larvae were susceptible to the nematode in the laboratory. Field application of the nematode in 2% aqueous Volck oil suspension against elm leaf beetle or spruce budworm larvae did not significantly reduce the populations when compared with controls. Desiccation of the infective nematodes may be a factor in the variable results for elm leaf beetle, and cool temperatures and rain may have been factors in the poor results for spruce budworm. However, significant population reduction occurred in nematode treatments against elm leaf beetle pupae in litter. This nematode may be used against beetle pupae in conjunction with other control tactics.

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.

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.

Relations among stand structure, dispersal of second-instar western spruce budworm, defoliation, and height growth of young conifers

1988 ◽  
Vol 18 (6) ◽  
pp. 796-802
Author(s):  
Clinton E. Carlson ◽  
Ward W. McCaughey ◽  
Leon J. Theroux
Keyword(s):  
Ponderosa Pine ◽  
Stand Structure ◽  
Basal Area ◽  
Spruce Budworm ◽  
Height Growth ◽  
Western Montana ◽  
Western Spruce Budworm ◽  
Mature Trees ◽  
Subalpine Fir ◽  
Host Trees

Local stand structure had little influence on dispersal of second-instar western spruce budworm (Choristoneuraoccidentalis Freeman). Numbers of dispersing larvae caught on traps averaged 37 larvae/m2 in the cut stands, as high as were found in adjacent uncut stands, and were not related to basal area of overstory in harvested stands, distance to the adjacent uncut stands, or budworm populations in the uncut stands. Despite high numbers of dispersing larvae, defoliation of host regeneration in cut stands was low (87% of the nonlarch host incurred less than 25% defoliation) and was not predictable (p ≤ 0.05) from dispersing larvae. Defoliation of mature trees in the adjacent uncut stands averaged 20% and ranged to 45%. Three-year height growth of postharvest host conifers in the cut stands increased with smaller overstory basal area, greater initial height, and greater crown ratio, but was not affected by the small amount of budworm defoliation. Regression models of 3-year height growth were similar among host western larch (Larixoccidentalis Nutt.), grouped nonlarch hosts (Douglas-fir, Pseudotsugamenziesii var. glauca (Beissn.) Franco; grand fir, Abiesgrandis (Dougl.) Forbes; and subalpine fir, A. lasiocarpa (Hook.) Nutt.), and grouped nonhosts (ponderosa pine, Pinusponderosa Dougl.; and lodgepole pine, P. contorta var. latifolia). Larval dispersal may be influenced more by forestwide conditions and spring weather than by local stand factors. Larvae reaching target seedlings likely are removed by predators such as birds and ants. Vigorous small host trees appear to be poor habitat for budworms; the insect had little effect on height growth of 5- to 20-year-old seral conifer stands of western Montana.

EFFECTS OF INSECT GROWTH REGULATORS ON THE WESTERN SPRUCE BUDWORM (CHORISTONEURA OCCIDENTALIS) (LEPIDOPTERA: TORTRICIDAE): I. LETHAL EFFECTS OF LAST INSTAR TREATMENTS

1979 ◽  
Vol 111 (12) ◽  
pp. 1361-1368 ◽  
Author(s):  
Jacqueline L. Robertson ◽  
Richard A. Kimball
Keyword(s):  
Growth Regulators ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Spray Application ◽  
Western Spruce Budworm ◽  
Insect Growth Regulators ◽  
Lethal Effects ◽  
Insect Growth ◽  
Model Combining ◽  
Combining Data

AbstractDosage–response relationships of seven insect growth regulators (IGRs) to last instar western spruce budworm, Choristoneura occidentalis Freeman, were determined by topical application, spray application, and diet incorporation bioassays. Mortality was defined as failure to emerge as a viable adult. In spray application experiments, four IGRs—ZR-512, ZR-619, ZR-1662, and Ro 10-3108—had LD50s of less than 70 g/ha (1 oz/acre). Relative lethal effectiveness, based on a simple model combining data from the three bioassays, was ZR-1662 > ZR-619 > ZR-512 > Ro 10-3108 > ZR-777 > ZR-587 > ZR-515. We concluded that several IGRs, applied to a population consisting primarily of last instars, would induce lethal effects at dosages comparable to dosages of several conventional insecticides.

AERIAL APPLICATION OF TWO BACULOVIRUSES AGAINST THE WESTERN SPRUCE BUDWORM, CHORISTONEURA OCCIDENTALIS FREEMAN (LEPIDOPTERA: TORTRICIDAE), IN BRITISH COLUMBIA

1989 ◽  
Vol 121 (3) ◽  
pp. 209-217 ◽  
Author(s):  
I.S. Otvos ◽  
J.C. Cunningham ◽  
W.J. Kaupp
Keyword(s):  
British Columbia ◽  
Nuclear Polyhedrosis Virus ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Choristoneura Occidentalis ◽  
Western Spruce Budworm ◽  
Granulosis Virus ◽  
Population Reduction ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis

AbstractTwo viruses, one a nuclear polyhedrosis virus and the other a granulosis virus, were applied in an attempt to initiate epizootics in populations of western spruce budworm, Choristoneura occidentalis Freeman, on Douglas-fir trees, Pseudotsuga menziesii (Mirb.) Franco, in southeastern British Columbia. Two 172-ha plots were aerially treated in 1982 with 9.0 kg of lyophilized, virus-infected larval powder that was formulated in an emulsifiable oil tank mix and applied at 9.4 L per hectare. Each plot was treated when larval populations were at the peak of the fourth instar. The nuclear polyhedrosis virus was applied at 5.4 × 1011 polyhedral inclusion bodies per hectare and the granulosis virus at 1.7 × 1014 capsules per hectare. Results showed that the granulosis virus treatment caused 34.6% population reduction (Abbott’s formula) and the nuclear polyhedrosis virus 51.8%. Larvae from treated and check plots were reared individually in the laboratory and the incidence of viruses, parasitoids, and successful adult emergence was recorded. Studies m these plots continued in 1983 and 1984. Although vertical transmission of both viruses was evident, their impact on budworm mortality was less than in 1982. Consequently, the epizootics were not sufficiently intense to control the target insect population.

EFFECTS OF NUCLEAR POLYHEDROSIS VIRUS AND BACILLUS THURINGIENSIS ON WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) 1 AND 2 YEARS AFTER AERIAL APPLICATION

1982 ◽  
Vol 114 (3) ◽  
pp. 281-282 ◽  
Author(s):  
R. F. Shepherd ◽  
T. G. Gray ◽  
J. C. Cunningham
Keyword(s):  
Bacillus Thuringiensis ◽  
Nuclear Polyhedrosis Virus ◽  
Spruce Budworm ◽  
Western Spruce Budworm ◽  
Aerial Application ◽  
Insect Populations ◽  
Polyhedrosis Virus ◽  
Nuclear Polyhedrosis ◽  
The Impact ◽  
Selection Of

An understanding of all environmental effects resulting from control actions is important in the selection of a method of managing insect populations. Effects may extend beyond the year of treatment and can modify management decisions. In 1978, a nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis Berliner (B.t.) were tested as aerial spray applications against the western spruce budworm, Choristoneura occidentalis Freeman, on Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, near Cache Creek, British Columbia. The impact on population densities and on the incidence of NPV was measured in the treated and non-treated areas for 2 vears following the year of application, and is reported here.

A method for sampling western spruce budworm pupae.

1981 ◽  
Author(s):  
Nilima Srivastava ◽  
Roy C. Beckwith ◽  
Robert W. Campbell ◽  
Torolf R. Torgersen
Keyword(s):  
Spruce Budworm ◽  
Western Spruce Budworm
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