Hostname: page-component-586b7cd67f-r5fsc Total loading time: 0 Render date: 2024-11-28T10:38:15.384Z Has data issue: false hasContentIssue false

EFFECTS OF DENSITY ON THE PROPORTION OF MALE AND FEMALE PUPAE IN GYPSY-MOTH POPULATIONS

Published online by Cambridge University Press:  31 May 2012

Yves Mauffette
Affiliation:
Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, Quebec H3A 1B1
Luc Jobin
Affiliation:
Laurentian Forest Research Centre, PO Box 3800, Sainte-Foy, Quebec G1V 4C7

Abstract

The numbers of larvae and pupae of the gypsy moth, Lymantria dispar L., were monitored in southwestern Quebec from June through August 1980 at 13 sites. In 10 sites, the proportion of male pupae was significantly different from an expected proportion of 0.5. Linear-regression analyses of the proportion of male pupae on larval density showed a significant increase in the number of male pupae with increasing larval density. Changes in the sex ratio could be an important indicator of the dynamic state of a population, and should be considered in modeling the population dynamics of gypsy moth.

Résumé

Les populations larvaires et de chrysalides de Lymantria dispar L. dans 13 sites localisés dans le sud-ouest du Québec ont été évaluées entre le début juin et le mois d'août 1980. Le nombre de chrysalides mâles dans 10 des sites échantillonnés était significativement différents de la valeur normale de 0.5. Les régressions linéaires obtenues de l'analyse du nombre de chrysalides mâles versus la densité larvaire indiquent une augmentation significative du nombre de chrysalides mâles avec l'accroissement de la densité des populations larvaires. Ces changements dans le rapport des sexes pourraient servir d'indices sur l'état et la dynamique des populations de la spongieuse.

Type
Articles
Copyright
Copyright © Entomological Society of Canada 1985

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

Andersen, F.S. 1961. Effect of density on animal sex ratio. Oikos 12: 116.CrossRefGoogle Scholar
Bess, H.A. 1961. Population ecology of the gypsy-moth (Porthetria dispar L.) (Lepidoptera: Lymantriidae). Conn. Agric. Exp. Stn. Bull. 646. 43 pp.Google Scholar
Burley, N. 1982. Facultative sex-ratio manipulation. Am. Nat. 120: 81107.CrossRefGoogle Scholar
Campbell, R.W. 1963. Some factors that distort the sex ratio of the gypsy moth Porthetria dispar (L.) (Lepidoptera: Lymantriidae). Can. Ent. 95: 465474.CrossRefGoogle Scholar
Campbell, R.W. 1967. Studies on the sex ratio of the gypsy moth. For. Sci. 13: 1922.Google Scholar
Campbell, R.W., Hubbard, D.L., and Sloan, R.J. 1975. Location of gypsy moth pupae and subsequent pupal survival in sparse, stable populations. Environ. Ent. 4: 597600.CrossRefGoogle Scholar
Doane, C.C., and McManus, M.L. 1981. The gypsy moth: Research toward integrated pest management. USDA Tech. Bull. 1584. 756 pp.Google Scholar
Goldschmidt, R. 1934. Lymantria. Bibliogr. Genet. 11: 1186.Google Scholar
Helwig, J.T., and Council, K.A. 1979. SAS User's Guide, 1979 ed. SAS Institute Inc., Raleigh, NC. 493 pp.Google Scholar
Leonard, D.E. 1970. Feeding rhythm in larvae of the gypsy moth. J. econ. Ent. 63: 14541457.CrossRefGoogle Scholar
Madrid, F.J., and Stewart, R.K. 1981. The influence of some environmental factors on the development and behavior of the gypsy moth (Lymantria dispar L.) in Quebec. Ann. Soc. Ent. Quebec 26: 191211.Google Scholar
Mason, C.J., and McManus, M.L. 1981. Larval dispersal of the gypsy moth. pp. 161–214 in The gypsy moth: Research toward integrated pest management. USDA Tech. Bull 1584. 756 pp.Google Scholar
Southwood, T.R.E. 1966. Ecological methods with particular references to the study of insect populations. Methuen, London. 391 pp.Google Scholar
Steel, R.G., and Torrie, J.H. 1960. Principles and procedures of statistics. McGraw-Hill Inc., NY. 481 pp.Google Scholar
Trivers, R.L., and Willard, D.E. 1973. Natural selection of parental ability to vary the sex ratio of offspring. Science 179: 9092.CrossRefGoogle ScholarPubMed
Wallner, W.E., and Walton, G.S. 1981. Host defoliation effects upon the gypsy moth. pp. 134–145 in The gypsy moth: Research toward integrated pest management. USDA Tech. Bull. 1584. 756 pp.Google Scholar
Werren, J.H., and Charnov, E.L. 1978. Facultative sex ratios and population dynamics. Nature (Lond.) 272: 349350.CrossRefGoogle ScholarPubMed
Weseloh, R.M. 1974. Relationships between different sampling procedures of gypsy moth Porthetria dispar (Lepidoptera: Lymantriidae) and its natural enemies. Can. Ent. 106: 225231.CrossRefGoogle Scholar
Williams, G.C. 1966. Adaptation and natural selection (A critique of some current evolutionary thought). Princeton Univ. Press, Princeton, NJ. 307 pp.Google Scholar