Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-04T17:57:09.416Z Has data issue: false hasContentIssue false
  • English
  • Français

RESOURCE USE AND CLONAL DIFFERENCES IN ATTACK RATE BY THE DOUGLAS-FIR SEED CHALCID, MEGASTIGMUS SPERMOTROPHUS WACHTL (HYMENOPTERA: TORYMIDAE), IN FRANCE

Published online by Cambridge University Press:  31 May 2012

Nancy Rappaport  and
Alain Roques
Nancy Rappaport
Affiliation:
USDA Forest Service, Pacific Southwest Forest and Range Experiment Station, PO Box 245, Berkeley, California, USA 94701
Alain Roques
Affiliation:
Institut National de la Recherche Agronomique, Centre de Recherches d'Orléans, Zoologie Forestère, Ardon 45160 Olivet, France
Get access Rights & Permissions [Opens in a new window]

Abstract

The within-cone distribution of Megastigmus spermotrophus Wachtl (Hymenoptera: Torymidae), the Douglas-fir seed chalcid, infesting Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] cones from north-central France was compared with that in samples from California. Results indicate that the mid-region of cones was more intensively utilized by seed chalcids in France than in California, whereas in the northwestern United States the mid-region is characteristically occupied by dipteran and lepidopteran species. This difference in distribution may explain the large discrepancy in infestation rates on the two continents. The potential impact of this finding on pest management strategies is discussed.

Cones were measured and dissected or X-rayed to determine seed chalcid infestation levels. Analysis of covariance performed on data from cones that were collected in 1986 and dissected showed cone diameter at maturity to be a highly significant factor in attack rate, although slopes were different among clones. Between-tree variation was also significant, but clonal source was not. Cone diameter, clonal source, and between-tree variation constituted 87.1% of the variation in rate of attack by the seed chalcid. Although clone was not a significant factor in data from dissected cones, X-rayed cones showed significant differences in attack rates for some clones.

Résumé

La répartition des larves de Megastigmus spermotrophus Wachtl (Hymenoptère : Torymidae) aux cônes du sapin de Douglas [Pseudotsuga menziesii (Mirb.) Franco] du nord-central de la France fut comparée à celle des échantillons de la Californie. Les données montrent que la région centrale des cônes était utilisée plus intensivement par les chalcidiens en France qu’en Californie, tandis qu’au nord-ouest des Etats-Unis cette région des cônes est, en règle générale, occupée par les lépidoptères et les diptères. Il se peut que ces différences en ce qui concerne la répartition puissent expliquer la grande différence entre les taux d’attaque par le chalcidien sur les deux continents. On discute l’impact éventuel de ces renseignements sur la lutte contre cette espèce.

Des cônes furent mesurés et disséqués ou radiographiés afin de constater les taux d’attaque par le chalcidien. L’analyse de covariance conduite aux données des cônes cueillis et disséqués en 1986 a montré un rapport linéaire très significatif entre le taux d’attaque et le diamètre des cônes, bien que les pentes soient hétérogènes entre clones. La variation entre-arbres fut aussi significative, mais la souche clonale ne fut pas significative. Diamètre des cônes, souche clonale, et variation entre-arbre ont constitué 87,1% de la variation de taux d’attaque par le chalcidien. Bien que la souche clonale ne soit pas une variable significative pour les cônes disséqués, les données des cônes soumis aux rayons-X ont montré les différences significatives entre taux d’attaque pour quelques clones.

Type
Articles
Information
The Canadian Entomologist , Volume 123 , Issue 6 , December 1991 , pp. 1219 - 1228
Copyright
Copyright © Entomological Society of Canada 1991

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

Annila, E. 1973. Chemical control of spruce cone insects in seed orchards. Comm. Inst. For. Fenn. 78: 1–25.Google Scholar
Anonymous. 1985. Minitab Reference Manual. Minitab, Inc., State College, PA 16801. 209 pp.Google Scholar
Bailey, B.J.R. 1977. Tables of the Bonferroni “t” statistic. J. Am. Stat. Assoc. 72: 469–478.Google Scholar
Dixon, W.J. (Ed.). 1981. BMDP Statistical Software. University of California Press, Berkeley, CA. 725 pp.Google Scholar
Games, P.A., and Howell, J.F.. 1976. Pairwise multiple comparison procedures with unequal N's and/or variances: A Monte Carlo study. J. Educ. Stat. 1: 113–125.Google Scholar
Hedlin, A.F., and Ruth, D.S.. 1978. Examinations of Douglas-fir clones for differences in susceptibility to damage by cone and seed insects. J. ent. Soc. B. C. 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. Canadian Forestry Service, USDA Forest Service, and Secretaria de Agricultura y Recursos Hidraulicos, Mexico (Co-op. Publ., unnumbered). 122 pp.Google Scholar
Ho, R.H. 1980. Pollination mechanism and seed production potential in Douglas-fir. For. Sci. 26: 522–528.Google Scholar
Hussey, N.W. 1955. The life-histories of Megastigmus spermotrophus Wachtl (Hymenoptera: Chalcidoidea) and its principal parasite, with descriptions of the developmental stages. Trans. R. ent. Soc. Lond. Pt. 2: 133–151.CrossRefGoogle Scholar
Hussey, N.W. 1956. The extent of seed loss in Douglas-fir caused by Megastigmus spermotrophus. Scott. For. 10: 191–197.Google Scholar
Jamblinne de Meux, A., and Nanson, A.. 1969. Résistance au Megastigmus chez divers peuplements et arbres semenciers de Pseudotsuga menziesii (Mirb.) Franco. Second World Consultation on Forest Tree Breeding, Washington, August 7–16 1969, FAO and IUFRO. 10 pp.Google Scholar
Keselman, H.J., and Rogan, J.C.. 1978. A comparison of the modified-Tukey and Scheffé methods of multiple comparisons for pairwise contrasts. J. Am. Stat. Assoc. 73: 47–52.Google Scholar
Koerber, T.W., and Markin, G.P.. 1984. Metasystox-R injections increase seed yield of Douglas-fir in California, Oregon, and Washington. pp. 137–146in Yates, H.O. III (Ed.), Proceedings IUFRO Cone and Seed Insects Working Party Conference, Athens, GA, USA.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. thesis, Faculty of Graduate Studies, University of British Columbia, Vancouver, B.C. 179 pp.Google Scholar
Kristek, J. 1967. Die verbreitung der Douglasien-samenschlupfwespe, Megastigmus spermotrophus Wachtl. (Hym., Torymidae). Acta Univ. Agric., Rocz. XXXVI, Sper c. 272: 275–286.Google Scholar
Lessman, D. 1974. Ein beitrag zur verbreitung und lebenweise von Megastigmus spermotrophus Wachtl und M. bipunctatus Swederus (Hymenoptera: Chalcidoidea). Z. Angew. Ent. 75: 1–42.CrossRefGoogle Scholar
Levins, R., and Wilson, M.. 1980. Ecological theory and pest management. A. Rev. Ent. 25: 287–308.CrossRefGoogle Scholar
Miller, G.E. 1984. Biological factors affecting Contarinia oregonensis (Diptera: Cecidomyiidae) infestations in Douglas-fir seed orchards on Vancouver Island, British Columbia. Environ. Ent. 13: 873–877.CrossRefGoogle Scholar
Rappaport, N.G., and Volney, W.J.A.. 1986. Resource utilization by insects colonizing Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) cones. pp. 157–166in Roques, A. (Ed.), Proceedings of the Second IUFRO Cone and Seed Insects Working Party Conference, Briançon, France.Google Scholar
Roques, A. 1981. Biologie et répartition de Megastigmus spermotrophus Wachtl. (Hymenoptera: Chalcidoidea Torymidae) et des autres insectes liés aux cônes dans les peuplements forestiers et vergers à graines français de sapin de Douglas Pseudotsuga menziesii [Mirb.] Franco. Acta Oecolog. Oecol. Appl. 2: 161–180.Google Scholar
Roques, A. 1983. Les insectes ravageurs des cônes et graines de conifères en France. Institut National de la Recherche Agronomique, 149 rue de Grenelle, 75341 Paris, France. 150 pp.Google Scholar
Roques, A. 1986. Dynamique d'infestation des nouveaux vergers à graines de Douglas du sud de la France par le chalcidien Megastigmus spermotrophus Wachtl. (Hymenoptère, Torymidae). 18th IUFRO World Congress, Ljubljana, Yugoslavia, Sept. 7–15, 1986. pp. 685–694.Google Scholar
Roques, A. 1987. Interaction between visual and olfactory signals in cone recognition by insect pests. pp. 153–160in Labeyrie, V., Fabres, G., and Lachaise, D. (Eds.), Plant–Insect Relationships. Junk Publishers, Dordrecht.Google Scholar
Roques, A., and Raimbault, J.-P.. 1985. Potentialités déstructices des insectes ravageurs dans les vergers à graines de Douglas du Lot. Station de Zoologie Forestière, Centre de Recherches Forestières (INRA) Ardon 45160 Olivet, France, R.F.F. 37: 26–32.Google Scholar
SAS Institute, Inc. 1982. SAS User's Guide: Statistics, 1982 ed. SAS Institute, Inc., Cary, NC. 584 pp.Google Scholar
Schnaider, Z. 1970. Megastigmus spermotrophus Wachtl. on the territory of Poland during years of 1967–1969. Sylwan Rocz. 165(11): 19–34.Google Scholar
Schneider, I. 1985. Wirtsfindung und Eiablage einiger Megastigmus-Arten, ein Beispiel fur K-orientierte Fort-pflanzungsstrategie bei Bewohnern extremer okologischer Nischen. Z. Angew. Ent. 100: 233–244.CrossRefGoogle Scholar
Schowalter, T.D., Haverty, M.I., Dombrosky, S.A., and Sexton, J.. 1986. Response of Douglas-fir cone gall midge and Douglas-fir seed chalcid to host plant genotype. pp. 217–223in Roques, A. (Ed.), Proceedings of the Second IUFRO Cone and Seed Insects Working Party Conference, Briançon, France.Google Scholar
Schowalter, T.D., Haverty, M.I., and Koerber, T.W.. 1985. Cone and seed insects in Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco, seed orchards in the western United States: Distribution and relative impact. Can. Ent. 117: 1223–1230.CrossRefGoogle Scholar
Shea, P.J. 1989. Interactions among phytophagous insect species colonizing cones of white fir (Abies concolor). Oecologia 81: 104–110.CrossRefGoogle ScholarPubMed
Stein, J.D., and Markin, G.P.. 1986. Evaluation of four chemical insecticides registered for control of the Douglas-fir cone gall midge, Contarinia oregonensis (Diptera: Cecidomyiidae), and the Douglas-fir seed chalcid, Megastigmus spermotrophus (Hymenoptera: Torymidae), in Douglas-fir seed orchards. Can. Ent. 118: 1185–1191.CrossRefGoogle Scholar
Summers, D., and Miller, G.E.. 1986. Experience with systemic insecticides for control of cone and seed insects in Douglas-fir seed orchards in coastal British Columbia, Canada. pp. 267–283in Roques, A. (Ed.). Proceedings of the Second IUFRO Cone and Seed Insects Working Party Conference. Briançon, France.Google Scholar
Volney, W.J.A. 1984. Competition and survival among insects colonizing Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) cones. pp. 77–84in Yates, H.O. III (Ed.), Proceedings IUFRO Cone and Seed Insects Working Party Conference, Athens. GA, USA.Google Scholar