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Adaptiveness of sex ratio control by the pupal parasitoid Itoplectis naranyae (Hymenoptera: Ichneumonidae) in response to host size

Abstract

Adaptiveness of sex ratio control by the solitary parasitoid wasp Itoplectis naranyae (Hymenoptera: Ichneumonidae) in response to host size was studied, by examining whether differential effects of host size on the fitness of resulting wasps are to be found between males and females. The offspring sex ratio (male ratio) decreased with increasing host size. Larger hosts yielded larger wasps. Male larvae were less efficient in consuming larger hosts than female larvae. No significant interaction in development time was found between parasitoid sex and host size. Larger female wasps lived longer than smaller females, while longevity of male wasps did not increase with increasing wasp size. Smaller males were able to mate either with small or with large females, while larger males failed to mate with small females. Larger female wasps had a greater number of ovarioles and mature eggs at any one time than smaller females, although the number of eggs produced per host-feeding was not influenced by female wasps. Thus, the differential effect of host size on the fitness of males and females exists in I. naranyae. The basic assumption of the host-size model was therefore satisfied, demonstrating that sex ratio control by I. naranyae in response to host size is adaptive.

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References

  1. Antolin, M.F., Ode, P.J. and Strand, M.R. (1995) Variable sex ratios and ovicide in an outbreeding parasitic wasp. Anim. Behav. 49, 589–600.

    Google Scholar 

  2. Assem, J. van den, Iersel, J.J.A. van and Hartogh, R.L.L. (1989) Is being large more important for female than male parasitic wasps? Behaviour 108, 160–195.

    Google Scholar 

  3. Charnov, E.L. (1979) The genetical evolution of patterns of sexuality: Darwinian fitness. Am. Nat. 113, 465–480.

    Google Scholar 

  4. Charnov, E.L. (1982) The Theory of Sex Allocation. Princeton University Press, Princeton, NJ.

    Google Scholar 

  5. Charnov, E.L., Los-den Hartogh, R.L., Jones, W.T. and Assem, J. van den (1981) Sex ratio evolution in a variable environment. Nature 289, 27–33.

    PubMed  Google Scholar 

  6. Cook, J.M., Rivero Lynch, A.P. and Godfray, H.C.J. (1994) Sex ratio and foundress number in the parasitoid wasp Bracon hebetor. Anim. Behav. 47, 687–696.

    Google Scholar 

  7. Eggleton, P. (1990) Male reproductive behaviour of the parasitoid wasp Lytarmes maculipennis (Hymenop-tera: Ichneumonidae). Ecol. Entomol. 15, 357–360.

    Google Scholar 

  8. Flanders, S.E. (1956) The mechanism of sex-ratio regulation in the parasitic Hymenoptera. Insectes Sociaux 3, 325–334.

    Google Scholar 

  9. Galloway, K.S. and Grant, B. (1989) Reverse sex-ratio adjustment in an apparently outbreeding wasp, Bracon hebetor. Evolution 43, 465–468.

    Google Scholar 

  10. Godfray, H.C.J. (1994) Parasitoids: Behavioral and Evolutionary Ecology. Princeton University Press, Princeton, NJ.

    Google Scholar 

  11. Goldsmith, S.K. (1987) The mating system and alternative reproductive behaviors of Dendrobias mandibularis (Coleoptera: Cerambycidae). Behav. Ecol. Sociobiol. 20, 111–115.

    Google Scholar 

  12. Hamilton, W.D. (1979) Wingless and fighting males in fig wasps and other insects. In Sexual Selection and Reproductive Competition in Insects (M.S. Blum and N.A. Blum, eds), pp. 167–220. Academic Press, New York.

    Google Scholar 

  13. Heinz, K.M. (1991) Sex-specific reproductive consequences of body size in the solitary ectoparasitoid, Dig-lyphus begini. Evolution 45, 1511–1515.

    Google Scholar 

  14. Jones, W.T. (1982) Sex ratio and host size in a parasitoid wasp. Behav. Ecol. Sociobiol. 10, 207–210.

    Google Scholar 

  15. Kazmer, D.J. and Luck, R.F. (1995) Field tests of the size-fitness hypothesis in the egg parasitoid Tricho-gramma pretiosum. Ecology 76, 412–425.

    Google Scholar 

  16. King, B.H. (1987) Offspring sex ratios in parasitoid wasps. Q. Rev. Biol. 62, 367–396.

    Google Scholar 

  17. King, B.H. (1988) Sex-ratio manipulation in response to host size by the parasitoid wasp Spalangia cameroni: A laboratory study. Evolution 42, 1190–1198.

    Google Scholar 

  18. King, B.H. (1993) Sex ratio manipulation by parasitoid wasps. In Evolution and Diversity of Sex Ratio in Insects and Mites (D.L. Wrensch and M. Ebbert, eds), pp. 418–441. Chapman & Hall, New York.

    Google Scholar 

  19. King, B.H. and King, R.B. (1995) Sex ratio manipulation in response to host size in the parasitoid wasp Spalangia cameroni: Is it adaptive? Behav. Ecol. 5, 448–454.

    Google Scholar 

  20. King, B.H. and Lee, H.E. (1994) Test of the adaptiveness of sex ratio manipulation in a parasitoid wasp. Behav. Ecol. Sociobiol. 35, 437–443.

    Google Scholar 

  21. McLachlan, A.J. and Allen, D.F. (1987) Male mating success in Diptera: Advantages of small size. Oikos 48, 11–14.

    Google Scholar 

  22. Partridge, L., Hoffmann, A. and Jones, J.S. (1987) Male size and mating success in Drosophila melanogaster and D. pseudoobscura under field conditions. Anim. Behav. 35, 468–476.

    Google Scholar 

  23. Phelan, P.L. and Baker, T.C. (1986) Male-size-related courtship success and intersexual selection in the tobacco moth, Ephestia elutella. Experientia 42, 1291–1293.

    Google Scholar 

  24. Seidl, S.E. and King, B.H. (1993) Sex-ratio manipulation by the parasitoid wasp Muscidifurax raptor in response to host size. Evolution 47, 1876–1882.

    Google Scholar 

  25. Steele, R.H. and Partridge, L. (1988) A courtship advantage for small males in Drosophila subobscura. Anim. Behav. 36, 1190–1197.

    Google Scholar 

  26. Ueno, T. (1994) Self-recognition by the parasitic wasp Itoplectis naranyae (Hymenoptera: Ichneumonidae). Oikos 70, 333–339.

    Google Scholar 

  27. Ueno, T. (1995) Abdominal tip movements during oviposition by two parasitoids (Hymenoptera: Ichneu-monidae) as an index of predicting the sex of depositing eggs. Appl. Ent. Zool. 30, 590–592.

    Google Scholar 

  28. Ueno, T. (1996) Estimation of host-size-dependent sex ratio in the parasitoid Itoplectis naranyae Ashmead (Hymenoptera: Ichneumonidae). Appl. Ent. Zool. 31, 613–615.

    Google Scholar 

  29. Ueno, T. and Tanaka, T. (1994) Comparative biology of six polyphagous solitary pupal endoparasitoids (Hymenoptera: Ichneumonidae): Differential host suitability and sex allocation. Ann. Entomol. Soc. Am. 87, 592–598.

    Google Scholar 

  30. Ueno, T. and Tanaka, T. (1997) Comparison between primary and secondary sex ratios in parasitoid wasps using a method for observing chromosomes. Entomol. Exp. Appl. 82, 105–108.

    Google Scholar 

  31. Waage, J.K. and Godfray, H.C.J. (1985) Reproductive strategies and population ecology of insect parasitoids. In Behavioural Ecology: Ecological Consequences of Adaptive Behaviour (R.M. Sibley and R.H. Smith, eds), pp. 449–470. Blackwell, Oxford.

    Google Scholar 

  32. Wellings, P.W., Morton, R. and Hart, P.J. (1986) Primary sex ratio and differential progeny survivalship in solitary haplo-diploid parasitoids. Ecol. Entomol. 11, 341–348.

    Google Scholar 

  33. Werren, J.H. (1987) Labile sex ratios in wasps and bees. BioScience 37, 498–506.

    Google Scholar 

  34. White, M.J.D. (1973) Animal Cytology and Evolution. Cambridge University Press, Cambridge.

    Google Scholar 

  35. Yasumatu, K. and Watanabe, C. (1965) A Tentative Catalogue of Insect Natural Enemies of Injurious Insects in Japan. Part 2: Host Parasite-Predator Catalogue. Entomology Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka.

    Google Scholar 

  36. Yuval, B., Wekesa, J.W. and Washino, R.K. (1993) Effect of body size on swarming behavior and mating success of male Anopheles freeborni (Diptera: Culicidae). J. Insect Behav. 6, 333–342.

    Google Scholar 

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Ueno, T. Adaptiveness of sex ratio control by the pupal parasitoid Itoplectis naranyae (Hymenoptera: Ichneumonidae) in response to host size. Evolutionary Ecology 12, 643–654 (1998). https://doi.org/10.1023/A:1006577314205

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  • fitness
  • host-size model
  • mating success
  • parasitoid
  • sex allocation
  • small male advantage