Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-24T15:00:13.776Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  31 May 2012

I.S. Otvos
Affiliation:
Canadian Forestry Service, Pacific Forestry Centre, Victoria, British Columbia, Canada V8Z 1M5
J.C. Cunningham
Affiliation:
Canadian Forestry Service, Forest Pest Management Institute, Sault Ste. Marie, Ontario, Canada P6A 5M7
W.J. Kaupp
Affiliation:
Canadian Forestry Service, Forest Pest Management Institute, Sault Ste. Marie, Ontario, Canada P6A 5M7
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Two 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.

Résumé

Deux virus, un virus à polyhédrose nucléaire et un virus à granulose, ont été appliqués lors d’une tentative de déclenchement d’épizooties dans les populations de la tordeuse occidentale de l’épinette, Choristoneura occidentalis Freeman, sur le sapin Douglas, Pseudotsuga menziesii (Mirb.) Franco, au sud est de la Colombie Britannique. Deux parcelles de 172 ha ont été traités par air en 1982 avec 9,0 kg de larves infectées, pulvérisées et formulées en huile émulsifiable appliquée à 9,4 L par hectare. Chaque parcelle a été traitée lorsque les populations larvaires étaient au pic de stade quatre. Le virus à polyhédrose nucléaire a été appliqué à 5,4 × 1011 corps d’inclusion polyhédriques par hectare et le virus à grandulose à 1,7 × 1011 capsules par hectare. Les résultats ont montré que le traitement au virus à granulose a causé 34,6% de réduction de la population (formule d’Abbott), et le virus à polyhédrose nucléaire, 51,8%. Des larves des parcelles traitées et témoins ont été élevées individuellement au laboratoire pour estimer les incidences de maladie virale, de parasitisme ou d’émergence d’un adulte. Les études dans ces parcelles se sont poursuivies en 1983 et 1984. Quoiqu’il ait été possible de conclure à la transmission verticale des deux virus, leur impact sur la mortalité de la tordeuse était moindre qu’en 1982. En conséquence, les épizooties n’étaient pas suffisamment intenses pour réprimer la population ciblée.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1989

References

Abbott, W.S. 1925. A method of computing the effectiveness of an insecticide. J. econ. Ent. 18: 265267.CrossRefGoogle Scholar
Alfaro, R.I. 1986. Mortality and top-kill in Douglas-fir following defoliation by the western spruce budworm in British Columbia. J. ent. Soc. B.C. 83: 1926.Google Scholar
Alfaro, R.I., Van Sickle, G.A., Thomson, A.J., and Wegwitz, E.. 1982. Tree mortality and radial growth losses caused by the western spruce budworm in a Douglas-fir stand in British Columbia. Can. J. For. Res. 12: 780787.CrossRefGoogle Scholar
Bergold, G.H. 1949. The polyhedral disease of the spruce budworm, Choristoneura fumiferana Clem. For. Insect. Invest. Bi-mon. Prog. Rep. 5(3): 2.Google Scholar
Clark, E.C. 1955. Observations on the ecology of a polyhedrosis of the Great Basin tent caterpillar Malacosoma fragilis. Ecology 36: 373376.CrossRefGoogle Scholar
Cunningham, J.C. 1985. Status of viruses as biocontrol agents for spruce budworms. pp. 6167in Proc. Symp. Microbial Control of Spruce Budworms and Gypsy Moths. Windsor Locks, CT. 1984. U.S.D.A. For. Serv. GTR-NE-100.Google Scholar
Cunningham, J.C., deGroot, P., and Kaupp, W.J.. 1986. A review of aerial spray trials with Lecontvirus for control of redheaded pine sawfly, Neodiprion lecontei (Hymenoptera: Diprionidae), in Ontario. Proc. ent. Soc. Ont. 117: 6572.Google Scholar
Cunningham, J.C., and Howse, G.M.. 1984. Choristoneura fumiferana (Clemens), spruce budworm (Lepidoptera: Tortricidae). B. Viruses: application and assessment. pp. 248259in Kelleher, J.S., and Hulme, M.A. (Eds.), Biological Control Programmes against Insects and Weeds in Canada 1969–1980. Commonw. Agric. Bureaux, Slough, U.K.Google Scholar
Cunningham, J.C., Kaupp, W.J., and McPhee, J.R.. 1983 a. A comparison of pathogenicity of two baculoviruses to the spruce budworm and western spruce budworm. Can. For. Serv. Res. Notes 3(2): 910.Google Scholar
Cunningham, J.C., Kaupp, W.J., McPhee, J.R., and Shepherd, R.F.. 1983 b. Ground spray trials with two baculoviruses on western spruce budworm. Can. For. Serv. Res. Notes 3(2): 1011.Google Scholar
Cunningham, J.C., and Shepherd, R.F.. 1984. Orgyia pseudotsugata (McDunnough), Douglas-fir tussock moth (Lepidoptera: Lymantriidae). pp. 363367in Kelleher, J.S., and Hulme, M.A. (Eds.), Biological Control Programmes against Insects and Weeds in Canada 1969–1980. Commonw. Agric. Bureaux, Slough U.K.Google Scholar
Entwistle, P.F., Cory, J.S., and Doyle, C.. 1988. An overview of baculovirus ecology as a background to field release of a genetically manipulated nuclear polyhedrosis virus. pp. 7280in Klingmüller, W. (Ed.), Risk Assessment for Deliberate Releases. Springer-Verlag, Berlin, Heidelberg.CrossRefGoogle Scholar
Evans, H.F., and Entwistle, P.F.. 1982. Epizootiology of the nuclear polyhedrosis virus of European spruce sawfly with emphasis on persistence of virus outside the host. pp. 449461in Kurstak, E. (Ed.), Microbial and Viral pesticides. Marcel Dekker, New York.Google Scholar
Fleming, R., and Retnakaran, A.. 1985. Evaluating single treatment data using Abbott's formula with reference to insecticides. J. econ. Ent. 78: 11791181.CrossRefGoogle Scholar
Griffiths, K.J., Cunningham, J.C., and Otvos, I.S.. 1984. Neodiprion sertifer (Geoffroy), European pine sawfly (Hymenoptera: Diprionidae). pp. 331340in Kelleher, J.S., and Hulme, M.A. (Eds.), Biological Control Programmes against Insects and Weeds in Canada 1969–1980. Commonw. Agric. Bureaux, Slough, U.K.Google Scholar
Harris, J.W.E., Alfaro, R.I., Dawson, A.F., and Brown, R.G.. 1985. The western spruce budworm in British Columbia, 1909–1983. Can. For. Serv., Pac. For. Centr., Inf. Rep. BC–X–257. 32 pp.Google Scholar
Harris, J.W.E., and Dawson, A.F.. 1979. Parasitoids of the western spruce budworm, Choristoneura occidentalis (Lepidoptera: Tortricidae), in British Columbia, 1977–78. J. ent. Soc. B.C. 76: 3038.Google Scholar
Hodgkinson, R.S., Finnis, M., Shepherd, R.F., and Cunningham, J.C.. 1979. Aerial applications of nuclear polyhedrosis virus and Bacillus thuringiensis against western spruce budworm. B.C. Min. For./Can. For. Serv. Joint Rep. 10. 19 pp.Google Scholar
Kaupp, W.J. 1983. Persistence of Neodiprion sertifer (Hymenoptera: Diprionidae) nuclear polyhedrosis virus on Pinus contorta foliage. Can. Ent. 115: 869873.CrossRefGoogle Scholar
Matthews, R.E.F. 1982. Classification and nomenclature of viruses. Fourth Rep. Int. Committee Taxon. Viruses, Intervirol. 17. 200 pp.Google Scholar
McMorran, A. 1965. A synthetic diet for the spruce budworm, Choristoneura fumiferana (Clem.)(Lepidoptera: Tortricidae). Can. Ent. 97: 5862.CrossRefGoogle Scholar
Otvos, I.S., Cunningham, J.C., and Alfaro, R.I.. 1987 a. Aerial application of nuclear polyhedrosis virus against Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae): 11. Impact 1 and 2 years after application. Can. Ent. 119: 707715.CrossRefGoogle Scholar
Otvos, I.S., Cuningham, J.C., and Friskie, L.M.. 1987 b. Aerial aplication of nuclear polyhedrosis virus against Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough) (Lepidoptera: Lymantriidae): 1. Impact in the year of application. Can. Ent. 119: 697706.CrossRefGoogle Scholar
Shepherd, R.F., and Cunningham, J.C.. 1984. Choristoneura occidentalis Freeman, western spruce budworm (Lepidoptera: Tortricidae). pp. 277279in Kelleher, J.S., and Hulme, M.A. (Eds.), Biological Control Programmes against Insects and Weeds in Canada 1969–1980. Commonw. Agric. Bureaux, Slough, U.K.Google Scholar
Shepherd, R.F., Gray, T.G., and Cunningham, J.C.. 1982. Effects of nuclear polyhedrosis virus and Bacillus thuringiensis on western spruce budworm one and two years after aerial application. Can. Ent. 114: 281282.CrossRefGoogle Scholar
Wood, C.S., Van Sickle, G.A., and Humble, L.M.. 1987. Forest insect and disease conditions, British Columbia and Yukon, 1987. Can. For. Serv., Pac. For. Centr., Inf. Rep. BC-X-296. 40 pp.Google Scholar
Van Sickle, G.A., Alfaro, R.I., and Thomson, A.J.. 1983. Douglas-fir height growth affected by western spruce budworm. Can. J. For. Res. 13: 445450.CrossRefGoogle Scholar
Wigley, P.J. 1980. Practical: counting micro-organisms. pp. 29–35 in Kalmakoff, J., and Longworth, J.F. (Eds.), Microbial Control of Insect Pests. New Zealand Dept. Sci. Indust. Res. Bull. 228.Google Scholar