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3.5 SUPPRESSION OF SPRUCE BUDWORM POPULATIONS BY TRICHOGRAMMA MINUTUM RILEY, 1982–1986

Published online by Cambridge University Press:  31 May 2012

S.M. Smith
Affiliation:
Faculty of Forestry, University of Toronto, Toronto, Ontario, Canada M5S 3B3
D.R. Wallace
Affiliation:
Forestry Canada, Ontario Region, Great Lakes Forestry Centre, PO Box 490, Sault Ste. Marie, Ontario, Canada P6A 5M7
G. Howse
Affiliation:
Forestry Canada, Ontario Region, Great Lakes Forestry Centre, PO Box 490, Sault Ste. Marie, Ontario, Canada P6A 5M7
J. Meating
Affiliation:
Forestry Canada, Ontario Region, Great Lakes Forestry Centre, PO Box 490, Sault Ste. Marie, Ontario, Canada P6A 5M7
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Abstract

The ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.

Résumé

La capacité du parasitoïde de l'oeuf, Trichogramma minutum Riley, à supprimer les populations éruptives de la tordeuse des bourgeons de l'épinette, Choristoneura fumiferana (Clemens), a été étudiée annuellement, près de Hearst, Ont., à partir de l'année 1982 jusqu'à l'année 1986 comprise. Le réglage de relâchements de parasitoïdes à la volée a été lié à l'éclosion et la ponte de la tordeuse. Ces rapports phénologiques ont été prédits d'une régression basée sur le développement larvaire au moins 2 semaines avant l'éclosion attendue; ceci a donné du temps suffisant à régler (à mettre en marche) l'éclosion des adultes de la tordeuse dans les cages a été utilisée pour contrôler l'éclosion du Lépidoptère dans les champs. Les pièges de phéromones ont fourni des renseignements journaliers concernant l'activité des mâles adultes et ont aidé à synchroniser les relâchements de parasitoïdes avec la ponte de la tordeuse. Les renseignements concernant l'activité des parasitoïdes ont été obtenus des masses d'oeufs de référence (élevages du laboratoire) et de celles qui se présentaient en nature. Un rapport curviligne entre la vitesse de relâchement du parasitoïde et le parasitisme des masses d'oeufs de référence a été développé. Deux relâchements de parasitoïdes, séparés de 1 semaine, au début de la ponte de la tordeuse, ont augmenté significativement le parasitisme des oeufs de l'hôte de 14–83% et ont réduit les populations larvaires également de 42–82%. Les relâchements simples ont été moins efficaces et ont augmenté le parasitisme de 0,3–52% (relâchements terrestres simples en 1986). Deux relâchements de parasitoïdes, joints à un traitement printanier des populations larvaires avec Bacillus thuringiensis Berliner, se sont montrés le stratège le plus efficace et ont eu comme résultat un parasitisme d'oeufs de 83% et une réduction de larves de 93%. Les taux de relâchement plus extensifs que de 12–16 × 106 ♀ ♀ T. minutum par hectare n'ont pas été justifiés d'une base d'effet et de frais. Ont été discutés les effets du relâchement, du réglage, du temps, de la densité de l'hôte et de la qualité du parasitoïde sur l'utilisation réussie à l'avenir de T. minutum.

Type
Research Article
Copyright
Copyright © Entomological Society of Canada 1990

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References

Anderson, J.F. 1976. Egg parasitoids of forest defoliating Lepidoptera. pp. 233–249 in Anderson, J.F., and Kaya, H.K. (Eds.), Perspective in Forest Entomology. Academic Press, New York. 428 pp.Google Scholar
Dorais, L., and Kettela, E.G.. 1982. A review of entomological survey and assessment techniques used in regional spruce budworm, Choristoneura fumiferana (Clem.) surveys and in the assessment of operational spray programs. Eastern Spruce Budworm Council Report. October. 43 pp.Google Scholar
Fleming, R., and Retnakaran, A.. 1985. Evaluating single treatment data using Abbot's formula with reference to insecticides. J. econ. Ent. 78: 11791181.Google Scholar
Houseweart, M.W., Jennings, D.T., and Lawrence, R.K.. 1984 a. Field releases of Trichogramma minutum (Hymenoptera: Trichogrammatidae) for suppression of epidemic spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae), egg populations in Maine. Can. Ent. 116: 13571366.Google Scholar
Houseweart, M.W., Jennings, D.T., Pease, S.H., and Lawrence, R.K.. 1984 b. Alternate insect hosts and characteristics of forest stands supporting native populations of Trichogramma minutum Riley. Misc. Rep. 300. Univ. Maine at Orono, Coll. For. Resour., Res. Bull. 5. 32 pp.Google Scholar
Houseweart, M.W., Southard, S.G., and Jennings, D.J.. 1982. Availability and acceptability of spruce budworm eggs to parasitism by the egg parasitoid Trichogramma minutum (Hymenoptera: Trichogrammatidae). Can. Ent. 114: 657666.Google Scholar
King, E.G., Bull, D.L., Bouse, L.F., and Phillips, J.R.. 1985. Introduction: Biological control of Heliothis spp. in cotton by augmentative releases of Trichogramma. Southwest. Ent. Suppl. 8: 19.Google Scholar
Knipling, E.F. 1977. The theoretical basis for augmentation of natural enemies, pp. 79–125 in Ridgway, R.L., and Vinson, S.B. (Eds.), Biological Control by Augmentation of Natural Enemies. Plenum Press, New York. 480 pp.Google Scholar
Kot, J. 1968. Factors affecting the efficiency of Trichogramma introduction. Proc. XIII Int. Cong. Ent. 2: 155158.Google Scholar
Kot, J. 1979. Analysis of factors affecting the phytophage reduction by Trichogramma Westw. species. Polish Ecol. Stud. 5: 559.Google Scholar
Lawrence, R.K., Houseweart, M.W., Jennings, D.T., Southard, S.G., and Halteman, W.A.. 1985. Development rates of Trichogmmma minutum (Hymenoptera: Trichogrammatidae) and implications for timing augmentative releases for suppression of egg populations of Choristoneura fumiferana (Lepidoptera: Tortricidae). Can. Ent. 117: 556563.Google Scholar
Lopez, J.D. Jr.,, and Morrison, R.K.. 1985. Parasitism of Heliothis spp. eggs after augmentative releases of Trichogramma pretiosum Riley. Southwest. Ent. Suppl. 8: 110137.Google Scholar
McGugan, B.M. 1954. Needle-mining habits and larval instars of the spruce budworm. Can. Ent. 86: 439454.Google Scholar
Ostle, G., and Mensing, R.W.. 1975. Statistics in Research. Iowa State University Press, Ames. 595 pp.Google Scholar
Pschorn-Walcher, H. 1977. Biological control of forest insects. A. Rev. Ent. 22: 122.Google Scholar
Régnière, J. 1982. A process-oriented model of spruce budworm phenology (Lepidoptera: Tortricidae). Can. Ent. 114: 811825.Google Scholar
Régnière, J. 1983. An oviposition model for the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae). Can. Ent. 115: 13711382.Google Scholar
Ridgway, R.E., Abies, J.R., Goodpasture, C., and Hartstack, A.W.. 1981. Trichogramma and its utilization for crop protection in the USA. Proceedings of the Joint American – Soviet Conference on Use of Beneficial Organisms in the Control of Crop Pests. Entomological Society of America, College Park, MD, USA.Google Scholar
Sanders, C.J. 1980. A summary of current techniques used for sampling spruce budworm populations and estimating defoliation in Eastern Canada. Can. For. Ser. Rep. 0-X-306.Google Scholar
Sanders, C.J. 1981. Release rates and attraction of PVC lures containing synthetic sex attractant of the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae). Can. Ent. 113: 11011106.Google Scholar
Sanders, C.J. 1986. Evaluation of high capacity, non-saturating sex pheromone traps for monitoring population density of spruce budworm (Lepidoptera: Tortricidae). Can. Ent. 118: 611619.Google Scholar
Smith, S.M. 1985. Feasibility of using the egg parasitoid, Trichogramma minutum Riley, for biological control of the spruce budworm. Ph.D. dissertation, University of Toronto, Toronto, Ont.221 pp.Google Scholar
Smith, S.M., and Hubbes, M.. 1985. Evaluation of aerial releases using Trichogramma minutum Riley for biological control of the spruce budworm. Rep. from the Faculty of Forestry, Univ. of Toronto to Pest Control Section, Ont. Min. Nat. Res., Maple, Ontario. March. 100 pp.Google Scholar
Smith, S.M., Hubbes, M., and Carrow, J.R.. 1987. Ground releases of Trichogramma minutum Riley (Hymenoptera: Trichogrammatidae) against the spruce budworm (Lepidoptera: Tortricidae). Can. Ent. 119: 251263.Google Scholar
Smith, S.M., Hubbes, M., and Carrow, J.R.. 1986. Factors affecting inundative releases of Trichogramma minutum against the spruce budworm. Zeit. angew. Ent. 101: 2939.Google Scholar
Thorpe, K.W. 1984. Seasonal distribution of Trichogramma (Hymenoptera: Trichogrammatidae) species associated with a Maryland soybean field. Environ. Ent. 13: 127132.Google Scholar
Van Hamburg, H., and Hassell, M.P.. 1984. Density dependence and the augmentative release of egg parasitoids against graminaceous stalkborers. Ecol. Ent. 9: 101108.Google Scholar
Witz, J.A., Hartstack, A.W., King, E.G., Dickerson, W.A., and Phillips, J.R.. 1985. Monitoring and prediction of Heliothis spp. Southwest. Ent. Suppl. 8: 5670.Google Scholar