Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-04T18:15:21.819Z Has data issue: false hasContentIssue false
  • English
  • Français

DISTRIBUTION OF CONTARINIA OREGONENSIS FOOTE (DIPTERA: CECIDOMYIIDAE) EGGS IN DOUGLAS-FIR SEED ORCHARDS AND A METHOD OF ESTIMATING EGG DENSITY

Published online by Cambridge University Press:  31 May 2012

G.E. Miller
G.E. Miller
Affiliation:
Canadian Forestry Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia, Canada V8Z 1M5
Get access Rights & Permissions [Opens in a new window]

Abstract

Efficient sampling procedures for estimating densities of eggs of Douglas-fir cone gall midge (DFCGM), Contarinia oregonensis Foote, on individual trees as well as for orchards were developed from data collected in Douglas-fir seed orchards in 1978–1981. Egg distribution was contagious and generally fitted the negative binomial distribution on individual trees, but a common k could not be estimated. Tree and crown level affected density of midge eggs within orchards. Average density at the midpoint of the cone-bearing portion of the crown was not significantly different from the tree average. The optimum sampling pattern in an orchard, i.e. one conelet from the midpoint of the cone-bearing portion of each of 120 trees, would require 120 person-hours to process the samples when DFCGM egg densities are high (worst-case situation).

Résumé

À partir de données recueillies dans des vergers à graines de Douglas taxifolié de 1978 à 1981, on a élaboré des méthodes efficaces d’échantillonnage pour l’estimation de la densité des oeufs de Contarinia oregonensis Foote sur les arbres ainsi que dans les vergers. La distribution des oeufs était contagieuse et correspondait généralement à une distribution binomiale négative sur les arbres individuels, mais on n’a pas réussi à estimer un k commun. Le niveau dans l’arbre et dans la cime influait sur la densité des oeufs. La densité moyenne pour le milieu de la partie de la cime portant des cônes ne différait pas de façon significative de la densité moyenne pour l’arbre. Le plan optimal d’échantillonnage dans un verger, c’est-à-dire un cônelet par arbre dans 120 arbres, exigerait 120 heures-personnes pour le traitement des échantillons lorsque la densité des oeufs est élevée (pire cas).

Type
Articles
Information
The Canadian Entomologist , Volume 118 , Issue 12 , December 1986 , pp. 1291 - 1295
Copyright
Copyright © Entomological Society of Canada 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Cochran, W. 1977. Sampling techniques, 3rd, ed. John Wiley and Sons, Toronto, 428 pp.Google Scholar
Hedlin, A.F. 1961. The life history and habits of a midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae) in Douglas-fir cones. Can. Ent. 93: 952–967.CrossRefGoogle Scholar
Hedlin, A.F., and Ruth, D.S.. 1978. Examination of Douglas-fir clones for differences in susceptibility to damage by cone and seed insects. J. ent. Soc. Brit. Columbia 75: 33–34.Google Scholar
Hedlin, A.F., Yates, H.O. III, Cibrian Tovar, D., Ebel, B.H., Koerber, T.W., and Merkel, E.P.. 1980. Cone and seed insects of North American conifers. Can. For. Serv./USDA For. Serv./Secr. Agric. Recur. Hidraul, Mexico. Victoria, British Columbia. 122 pp.Google Scholar
Kozak, A. 1963. Analysis of some factors associated with distribution and intensity of attack by cone and seed insects in Douglas-fir. Ph.D. dissertation, Univ. B.C., Vancouver, British Columbia. 179 pp.Google Scholar
Miller, G.E. 1980. Pest management in Douglas-fir seed orchards in British Columbia: a problem analysis. Simon Fraser University. Pest Management Paper 22. 138 pp.Google Scholar
Miller, G.E. 1983. Evaluation of the effectiveness of cold-water misting of trees in seed orchards for control of Douglas-fir cone gall midge. J. econ. Ent. 76: 916–919.CrossRefGoogle Scholar
Miller, G.E. 1984. Biological factors affecting Contarinia oregonensis infestations in Douglas-fir seed orchards on Vancouver Island, British Columbia. Environ. Ent. 13: 873–877.CrossRefGoogle Scholar
Miller, G.E., and Borden, J.H.. 1984. Reproductive behavior of the Douglas-fir cone gall midge, Contarinia oregonensis Foote (Diptera: Cecidomyiidae). Can. Ent. 116: 607–618.CrossRefGoogle Scholar
Southwood, T.R.E. 1978. Ecological methods with particular reference to the study of insect populations, 2nd ed. John Wiley and Sons, New York.Google Scholar
Stauffer, H.B. 1983. Some sample size tables for forest sampling. Brit. Columbia Min. For. Res. Note 90. 50 pp.Google Scholar
Taylor, L.R. 1961. Aggregation, variance and the mean. Nature Lond. 189: 732–735.CrossRefGoogle Scholar
Winjum, J.K., and Johnson, N.E.. 1964. Differences in cone numbers, lengths, and cut-counts in the crowns of young open-grown Douglas-fir. J. For. 62: 389–391.Google Scholar