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NUMBER AND SIZE OF EGGS IN EGG MASSES OF THE WESTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

Published online by Cambridge University Press:  31 May 2012

Robert W. Campbell
Affiliation:
USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, Corvallis, Oregon 97331
Torolf R. Torgersen
Affiliation:
USDA Forest Service, Pacific Northwest Forest and Range Experiment Station, La Grande, Oregon 97850
Nilima Srivastava
Affiliation:
College of Forestry, Wildlife and Range Sciences, University of Idaho, Moscow, Idaho 83843

Abstract

Foliage of Douglas-fir and grand fir bearing egg masses of the western spruce budworm, Choristoneura occidentalis Freeman, was collected from sites in Oregon, Idaho, and Montana. Later, 4154 of these egg masses were examined in the laboratory. The average number of eggs per mass was 47.5 ± 10.65 (range 23–58). The number of eggs in a mass increased as defoliation of current foliage increased from none to moderate. The average number of eggs per linear millimeter of a single row ranged among sites from 1.24 ± 0.02 to 2.43 ± 0.21. The average number of eggs per linear millimeter of a row was highest (1.99) among the sites studied in Idaho, and lowest (1.58) among the sites studied in Oregon.

Résumé

Du feuillage du sapin de Douglas et du sapin de Vancouver portant des masses d'oeufs de la tordeuse occidentale de l'épinette, Choristoneura occidentalis Freeman, a été recueilli à plusieurs endroits en Oregon, en Idaho et au Montana. Par la suite, 4,154 de ces masses ont été examinées au laboratoire. Le nombre moyen d'oeufs par masse était de 47.5 ± 10.65 (écart 23–58). Le nombre d'oeufs par masse a augmenté pendant que la défoliaison du feuillage courant est passée de nulle à modérée. Le nombre moyen d'oeufs par millimètre linéaire d'une rangée simple a varié de 7.24 ± 0.02 à 2.43 ± 0.21 entre ces sites. Parmi les sites étudiés le nombre moyen d'oeufs par millimètre linéaire de rangée était maximum (1.99) en Idaho, et minimum (1.58) pour les sites étudiés en Oregon.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1984

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References

Bean, J. L. 1961. A method for estimating the number of spruce budworm eggs per egg mass. J. econ. Ent. 54: 1064.CrossRefGoogle Scholar
Capinera, J. L. and Barbosa, P.. 1976. Dispersal of first instar gypsy moth larvae in relation to population quality. Oecologia (Berl.) 26: 5360.CrossRefGoogle ScholarPubMed
Greenbank, D. O., Schaefer, G. W., and Rainey, R. C.. 1980. Spruce budworm (Lepidoptera: Tortricidae) moth flight and dispersal: new understanding from canopy observations, radar, and aircraft. Mem. ent. Soc. Can. 110. 49 pp.Google Scholar
Harris, J. W. E. 1963. Sampling the egg stages of the two-year-cycle spruce budworm near Babine Lake, British Columbia. For. Chronicle 39: 199204.Google Scholar
Harris, J. W. E. and Dawson, A. F.. 1982. Estimating number of western spruce budworm eggs from egg mass measurements in British Columbia. Can. Ent. 114: 643645.CrossRefGoogle Scholar
Harvey, G. T. 1977. Mean weight and rearing performance of successive egg clusters of eastern spruce budworm (Lepidoptera: Tortricidae). Can. Ent. 109: 487496.CrossRefGoogle Scholar
Leonard, D. E. 1971. Population quality. pp. 720in Toward integrated control. U.S. Dep. Agric. For. Serv. Res. Pap. NE-194. Northeast For. Exp. Stn., Broomall, Pennsylvania.Google Scholar
McKnight, M. E. 1969. Estimating numbers of eggs in western spruce budworm egg masses. U.S. Dep. Agric. For. Serv. Res. Note RM-146. 4 pp. Rocky Mt. For. and Range Exp. Stn., Fort Collins, Colorado.Google Scholar
Miller, C. A. 1957. A technique for estimating the fecundity of natural populations of the spruce budworm. Can. J. Zool. 35: 113.CrossRefGoogle Scholar
Neter, J. and Wasserman, W.. 1974. Applied linear statistical models. Richard D. Irwin, Inc., Homewood, IL. 842 pp.Google Scholar
Otvos, I. S. 1977. Estimating the number of eggs in spruce budworm egg masses in Newfoundland. Can. For. Serv. Bi-mon. Res. Notes 33(3): 17.Google Scholar
Washburn, R. I. and Brickell, J. E.. 1973. Western spruce budworm egg mass dimensions—an influence on population estimates. U.S. Dep. Agric. For. Serv. Res. Pap. Int-138. 20 pp. Intermountain For. and Range Exp. Stn., Ogden, Utah.Google Scholar
Wellington, W. G. 1957. Individual differences as a factor in population dynamics: the development of a problem. Can. J. Zool. 35: 293323.CrossRefGoogle Scholar
Wellington, W. G. 1977. Returning the insect to insect ecology: some consequences for pest management. Environ. Ent. 6: 18.CrossRefGoogle Scholar