Summary
Black pineleaf scale insect populations are subdivided into genetically differentiated demes associated with individual pine trees. A comparison of sex ratios early and late in the life cycle demonstrated differences in the mortality experienced by haploid males and diploid females. Hatching ratios were significantly female-biased, and differential mortality increased this bias in ratios estimated just before adult male eclosion. The relative survival of males and females varied with overall mortality, causing a correlation between local densities and the surviving sex ratio. We suggest (a) that the genetic differentiation of scale demes results in part from selection pressures associated with individual pine trees, (b) that this differentiation entails an accumulation of locally adaptive traits within the scale subpopulation on each tree, (c) that expression of these adaptations in the haploid and diploid sexes may vary with their frequencies, and (d) that the surviving sex ratio thus offers a comparative measure of selection and the local adaptation achieved by the insects in individual demes.
Similar content being viewed by others
References
Alstad, D. N. and Corbin, K. W. Allozyme variation associated with local differentiation of scale insect demes on individual host trees (in review, 25 ms pp).
Alstad, D. N., Edmunds, G. F. Jr and Johnson, S. C. (1980) Host adaptation sex ratio, and flight activity in male black pineleaf scale.Ann. Ent. Soc. Amer. 73, 665–7.
Alstad, D. N. and Edmunds, G. F. Jr (1983a) Selection, outbreeding depression, and the sex ratio of scale insects.Science 220, 93–5.
Alstad, D. N. and Edmunds, G. F. Jr (1983b) Adaptation, host specificity and gene flow in the black pineleaf scale.Variable Plants and Herbivores in Natural and Managed Systems. R. F. Denno and M. S. McClure (eds), pp 413–26. Academic Press, New York, USA.
Alstad, D. N. and Edmunds, G. F. Jr (1987) Black pineleaf scale population density in relation to interdemic mating (Hemiptera: Diaspididae).Ann. Ent. Soc. Amer. 7, 532–6.
Brown, S. W. (1958) Haplodiploidy in the Diaspididae — confirmation of an evolutionary hypothesis.Evolution 12, 115–16.
Brown, S. W. and McKenzie, H. L. (1962) Evolutionary patterns in the armored scale insects and their allies.Hilgardia 33, 140–70.
Bull, J. J. (1983)Evolution of Sex Determining Mechanisms. Benjamin/Cummings, Menlo Park, CA, 316 pp.
Bulmer, M. G. and Taylor, P. D. (1980) Dispersal and the sex ratio.Nature 284, 448–9.
Charlesworth, B. and Toro, M. A. (1982) Female-biased sex ratios,Nature 298, 494.
Charnov, E. L. (1982) The theory of sex allocation.Princeton University Press Monographs in Population Biology No. 18, 355 pp.
Colwell, R. K. (1981) Group selection is implicated in the evolution of female-biased sex ratios.Nature 290, 401–4.
Edmunds, G. F. Jr (1973) Ecology of black pineleaf scale (Homoptera: Diaspididae).Envir. Ent. 2, 765–77.
Edmunds, G. F. Jr and Alstad, D. N. (1978) Coevolution in insect herbivores and conifers.Science 199, 941–5.
Edmunds, G. F. Jr and Alstad, D. N. (1981) Responses of Black Pineleaf Scales to host plant variability.Insect Life History Patterns. R. F. Denno and H. Dingle (eds), pp 29–38. Springer-Verlag, New York, USA.
Edmunds, G. F. Jr and Alstad, D. N. (1984) High summer mortality of black pineleaf scale (Homoptera: Diaspididae).Pan. Pac. Ent. 60, 267–8.
Endler, J. A. (1986) Natural selection in the wild.Princeton University Press, Monographs in Population Biology No. 21, 336 pp.
Ferris, G. F. (1937–1955)Atlas of the Scale Insects of North America. Stanford University Press, Stanford, CA, USA.
Furniss, R. L. and Carolin, V. M. (1977) Western Forest Insects.USDA Forest Service Mic. Pub. No. 1339.
Haldane, J. B. S. (1924) A mathematical theory of natural and artificial selection. Part I.Trans. Camb. Phil. Soc. 23, 19–41.
Hamilton, W. D. (1967) Extraordinary sex ratios.Science 156, 477–88.
Harvey, P. H., Partridge, L. and Nunney L. (1985) Group selection and the sex ratio.Nature 313, 10–11.
Herre, E. A. (1985) Sex ratio adjustment in fig wasps.Science 228, 896–8.
Kacser, H. and Burns, J. A. (1981) The molecular basis of dominance.Genetics 97, 639–66.
Linhart, Y. B., Mitton, J. B., Sturgeon, K. B., and Davis, M. L. (1979) An analysis of genetic architecture in populations of ponderosa pine.Pr. Symp. on Isozymes of North American Forest Trees and Forest Insects. USDA Forest Service, 27 July 1979, Berkeley.
Linhart, Y. B., Mitton, J. B., Sturgeon, K. B. and Davis, M. L. (1981) Genetic variation in space and time in a poulation of ponderosa pine.Heredity 46, 407–26.
Maynard Smith, J. M. (1978)The Evolution of Sex. Cambridge University Press, UK, 222 pp.
Merrill, D. J. (1968) The evolutionary role of dominant genes.Genetics Lectures, Vol. I R. Bogart (ed.) Oregon State University Press, Corvallis, USA.
Mitton, J. B. (1983) Conifers.Isozymes in Plant Genetics and Breeding Part B. S. D. Tanksley and T. J. Orton (eds), pp 443–72. Elsevier Science Publishers B. V., Amsterdam.
Mitton, J. B., Linhart, Y. B., Davis, M. L. and Sturgeon, K. B. (1981) Estimation of outcrossing in ponderosa pine,Pinus ponderosa Laws., from patterns of segregation of protein polymorphisms and from frequencies of albino seedlings.Silvae Genetica 30, 117–21.
Nunney, L. (1985a) Female-biased sex ratios: individual or group selection?Evolution 39, 349–61.
Nunney, L. (1985b) Group selection, altruism, and structured-deme models.Amer. Natur. 126, 212–30.
Nur, U. (1967) Reversal of heterochromatization and the activity of the paternal chromosome set in the male mealy bug.Genetics 56, 375–89.
Stoetzel, M. B. and Davidson, J. A. (1974) Sexual dimorphism in all stages of the Aspidiotini (Homoptera: Diaspididae).Ann. Ent. Soc. Amer. 67, 138–40.
Sturgeon, K. B. (1979) Monoterpene variation in ponderosa pine xylem resin in relation to western pine beetle predation.Evolution 33, 803–14.
Taylor, P. D. and Bulmer, M. G. (1980) Local mate competition and the sex ratio.J. Theor. Biol. 86, 409–19.
Tippins, H. H. and Howell, J. O. (1973) A new genus and species of Diaspididae (Homoptera: Coccoidea) from Georgia.Ann. Ent. Soc. Amer. 66, 399–403.
Turner, J. R. G. (1981) Adaptation and evolution inHeliconius: a defense of neoDarwinism.Ann. Rev. Ecol. Syst. 12, 99–121.
Werren, J. H. (1980) Sex ratio adaptations to local mate competition in a parasitic wasp.Science 208, 1157–9.
Wilson, D. S. (1983) The group selection controversy: history and current status.Ann. Rev. Ecol. Syst. 14, 159–87.
Wilson, D. S. and Colwell, R. K. (1981) Evolution of sex ratio in structured demes.Evolution 35, 882–97.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Alstad, D.N., Edmunds, G.F. Haploid and diploid survival differences demonstrate selection in scale insect demes. Evol Ecol 3, 253–263 (1989). https://doi.org/10.1007/BF02270726
Issue Date:
DOI: https://doi.org/10.1007/BF02270726