Summary
We tested predictions of sex allocation theory with a series of field experiments on sex allocation in an herbivorous, haplodiploid, sawfly, Euura lasiolepis. Our experiments demonstrated the following points. 1) Adult females allocated progeny sex in response to plant growth. 2) Population sex ratios varied in response to plant quality, being male-biased where plant growth was slow and female-biased where plant growth was rapid. 3) Family sex ratios varied in response to plant quality, being male-biased on slow-growing plants and female-biased on rapidly-growing plants. 4) Female fitness increased more rapidly as the result of developing on more rapidly-growing plants than male mass. We conclude from these results that there are unequal returns on investment in male and female progeny. This results in facultatively biased sawfly sex ratios as an adaptive response to variation in plant quality.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bull JJ (1981) Sex ratio evolution when fitness varies. Heredity 46:9–26
Carne PB (1969) On the population dynamics of the eucalypt-defoliating sawfly Perga affinis affinis Kirby (Hymenoptera). Aust J Zool 17:113–141
Charnov EL (1982) The theory of sex allocation. Princeton University Press, Princeton
Clausen CD (1939) The effect of host size upon the sex ratio of hymenopterous parasites and its relation to methods of rearing and colonization. J N Y Ent Soc 47:1–9
Craig TP, Mopper S (1993) Sex ratio variation in sawflies. In: Sawfly adaptations to woody plant, Wagner MR and Raffa KF (eds), Academic Press, New York, in press
Craig TP, Price PW, Itami JK (1986) Resource regulation by a stem-galling sawfly on the arroyo willow. Ecology 67:419–425
Craig TP, Price PW, Clancy KM, Waring G, Sacchi CF (1988) Forces preventing coevolution in the three-trophic-level system: willow, a gall-forming herbivore, and parasitoids. In: Spencer KC (ed), Chemical mediation of coevolution. Academic Press, New York, pp 57–80
Craig TP, Itami JK, Price PW (1989) A strong relationship between oviposition preference and larval performance in a shoot-galling sawfly. Ecology 70:1691–1699
Craig TP, Itami JK, Price PW (1990) Intraspecific competition and facilitation by a shoot-galling sawfly. J Anim Ecol 59:147–159
Crespi BJ (1988) Sex-ratio selection in bivoltine thrips. I. Conditional sex-ratio manipulation and fitness variation. Evolution 42:1199–1211
Fisher RA (1930) The genetical theory of natural selection. Oxford Univ. Press, Oxford
Flanders SE (1956) The mechanisms of sex-ratio regulation in the (parasitic) Hymenoptera. Insect Sociaux 3:325–334
Frank SA (1987) Individual and population sex allocation patterns. Theor Pop Biol 31:47–74
Frank SA (1990) Sex allocation theory for birds and mammals. Ann Rev Ecol Syst 21:31–55
Hard JS, Togerson TR (1975) Field and laboratory techniques for evaluating hemlock sawfly infestations. USDA For Serv Res Note PNW-22
King BT (1987) Offspring sex ratios in parasitoid wasps. Quart Rev Biol 62:367–396
King BT (1988) Sex-ratio manipulation in response to host size by the parasitoid wasp Spalangia cameroni: A laboratory study. Evolution 42:1190–1198
Mopper S, Whitham TG (1992) The plant stress paradox: effects on pinyon sawfly sex ratios and fecundity. Ecology 73:515–525
Preszler RW, Price PW (1988) The effects of variable host quality on sawfly populations: a new approach to life table analysis. Ecology 69:2012–2021
Price PW, Craig TP (1984) Life history, phenology, survivorship of a stem galling sawfly, Euura lasiolepis in Northern Arizona. Ann Entomol Soc Am 77:712–719
Price PW, Clancy KM (1986) Multiple effects of precipitation on Salix lasiolepis and populations of the stem-galling sawfly, Euura lasiolepis. Ecol Res 1:1–14
Price PW, Cobb N, Craig TP, Fernandes GW, Itami J, Mopper S, Preszler R (1990) Insect herbivore population dynamics on trees and shrubs: new approaches relevant to latent and eruptive species. In: Bernays EA (ed) Focus on insect-plant interactions, Vol. 2 CRC Press, Boca Raton, pp 1–38
Sandlan K (1979) Sex ratio regulation in Coccygomimus turionella Linnacus (Hymenoptera: Ichneumonidae) and its ecological implications. Ecol Entomol 4:365–378
Wellings PW, Morton R, Hart PJ (1986) Primary sex-ratio and differential progeny survivorship in solitary haplo-diploid parasitoids. Ecol Entomol 11:341–348
Werren JH (1986) Labile sex ratios in wasps and bees. Bioscience 37:498–506
Young SSY, Wrensch DL, Kongchuensin M (1986) Control of sex ratio in female spider mites. Entomol Exp Appl 40:53–60
Zar JH (1984) Biostatistical analysis, 2nd Ed. Prentice Hall Inc., Englewood Cliffs
Zhang ZY, Wagner MR (1991) Cocoon and adult parameters predict fecundity of the pine sawfly Neodiprion fulviceps. Southwestern Entomologist 16:193–198
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Craig, T.P., Price, P.W. & Itami, J.K. Facultative sex ratio shifts by a herbivorous insect in response to variation in host plant quality. Oecologia 92, 153–161 (1992). https://doi.org/10.1007/BF00317357
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00317357