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Offspring sex ratio of a cereal aphid parasitoid, Lysiphlebus delhiensis (Subba rao & Sharma) in response to maternal crowding

Published online by Cambridge University Press:  19 September 2011

Shilu Biswas
Affiliation:
Aphid Biocontrol Laboratory, Department of Zoology, University of Gorakhpur, Gorakhpur-273 009, UP, India
Rajendra Singh
Affiliation:
Aphid Biocontrol Laboratory, Department of Zoology, University of Gorakhpur, Gorakhpur-273 009, UP, India
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Abstract

The effect of maternal crowding on the offspring sex ratio of a cereal aphid parasitoid Lysiphlebus delhiensis (Subba Rao & Sharma) (Hymenoptera: Braconidae) was examined. Increasing the number of mothers per host-patch always increased the proportion of males in the population (p). The extent of variations in p at different levels of maternal crowding was compared with the prediction of the Hamiltonian LMC model, i.e. p = (n-1)/2n, where n = number of mothers/host-patch. The perception of trace odours of conspecific females induced haploid oviposition. Differential mortality of the larvae by sex in superparasitised hosts, shifting the p towards sons has been discussed. The inversely parasitoid-density-dependent p indicates that for obtaining maximum number of female progeny, the ratio of female parasitoid to the host in mass breeding should not be less than 1:100 at a time.

Résumé

L'effet de la surpopulation maternelle sur le rapport des sexes dans la progéniture d'un parasitoïde du puceron des céréales Lysiphlebus delhiensis (Subba Rao & Sharma) a été examiné. L'augmentation du nombre de mères par hôte s'accompagnait toujours d'une augmentation de la proportion des mâles dans la population (p). Le degré des variations de p à différents niveaux de surpopulation maternelle a été comparé à la prédiction du modèle Hamiltonian LMC, à savoir p = (n-1)/2n, où n = le nombre de mères/hôte. La perception des traces d'odours de femelles conspécifiques induisait la production d'oeufs haploïdes. La mortalité larvaire differentielle par sexe chez les hôtes superparasites, faisant basculer les valeurs de p en faveur des mâles a été discutée. Les valeurs de p en rapport inverse de la densité du parasitoïde montre que pour obtenir un nombre maximal de femelles dans la progéniture, le rapport du parasitoïde femelle par hôte en élevage en masse ne devrait jamais être inférieur à 1:100.

Type
Research Articles
Copyright
Copyright © ICIPE 1995

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References

REFERENCES

Bhatt, N. and Singh, R. (1991a) Bionomics of an aphidiid parasitoid Trioxys indicus Subba Rao & Sharma. 33. Impact of food plants on the behaviour of and sex allocation by the female parasitoid at varying densities. Biol. Agric. Hort. 7, 247259.CrossRefGoogle Scholar
Bhatt, N. and Singh, R. (1991b) Impact of male parasitoid Trioxys indicus on the reproductive strategy of the female on different food plants. Indian J. Ecol. 18, 3640.Google Scholar
Decker, U. M., Powell, P. W. and Clark, S. J. (1993) Sex pheromones in the cereal aphid parasitoids Praon volucre and Aphidius rhopalosiphi. Entomol. Exp. Appl. 69, 3339.CrossRefGoogle Scholar
Fisher, R. A. (1930) The Genetic Theory of Natural Selection. Oxford University Press, London.Google Scholar
Hamilton, W. D. (1967) Extraordinary sex ratios. Science 156, 477488.CrossRefGoogle ScholarPubMed
Holmes, H. B. (1972) Genetic evidence for fewer progeny and higher percent males when Nasonia vitripennis oviposits in previously parasitised hosts. Entomophaga 17, 7988.CrossRefGoogle Scholar
King, B. H. (1987) Offspring sex ratios in parasitic wasps. Q. Rev. Biol. 62, 367396.CrossRefGoogle Scholar
King, B. H. (1989) A test of local mate competition theory with a solitary species of parasitoid wasp, Spalangia cameroni. Oikos 54, 5054.CrossRefGoogle Scholar
Mishra, S. and Singh, R. (1990a) Effect of parasitisation by the cereal aphid parasitoid Lysiphlebus delhiensis (Subba Rao & Sharma) (Hymenoptera: Aphidiidae) at its varying densities. J. Appl. Entomol. 109, 251261.CrossRefGoogle Scholar
Mishra, S. and Singh, R. (1990b) Life-time performance of an aphid parasitoid Lysiphlebus delhiensis (Hymenoptera: Aphidiidae). Entomol. Gen. 15, 173179.CrossRefGoogle Scholar
Mishra, S. and Singh, R. (1991) Sex ratio of the aphid parasitoid Lysiphlebus delhiensis (Subba Rao & Sharma) (Hymenoptera: Aphidiidae) in field population. J. Appl. Entomol. 111, 7277.CrossRefGoogle Scholar
Mishra, S. and Singh, R. (1993) Factors affecting supernumerary egg deposition by the parasitoid Lysiphlebus delhiensis (Subba Rao & Sharma) (Hymenoptera: Aphidiidae) into its host Rhopalosiphum maidis (Fitch). Biol. Agric. Hort. 10, 3945.CrossRefGoogle Scholar
Nunney, L. (1985) Female-biased sex ratios: Individual or group selection? Evolution 39, 349361.CrossRefGoogle ScholarPubMed
Singh, R. and Agarwala, B. K. (1992) Biology, ecology and control efficiency of the aphid parasitoid Trioxys indicus: A review and bibliography. Biol. Agric. Hort. 8, 271298.CrossRefGoogle Scholar
Singh, R. and Sinha, T. B. (1982) Bionomics of Trioxys indicus, an aphidiid parasitoid of Aphis craccivora. 10. Superparasitism caused by confinement with the hosts. Entomol. Exp. Appl. 32, 227231.CrossRefGoogle Scholar
Sinha, T. B. and Singh, R. (1979) Studies on the bionomics of Trioxys (Binodoxys) indicus (Hymenoptera: Aphidiidae). Effect or population densities on the sex ratio. Entomophaga 24, 289294.CrossRefGoogle Scholar
Sinha, T. B. and Singh, R. (1980) Bionomics of Trioxys (Binodoxys) indicus, an aphidiid parasitoid of Aphis craccivora. 3. Numerical aspects of interaction of the parasitoid and its host. Entomol. Exp. Appl. 28, 167176.CrossRefGoogle Scholar
Srivastava, M. and Singh, R. (1994) Sex ratio adjustment by a koinobiotic parasitoid Lysiphlebus delhiensis (Subba Rao & Sharma) (Hymenoptera: Aphidiidae) in response to host size. Biol. Agric. Hort. 12, 1528.CrossRefGoogle Scholar
Suzuki, Y., Tsuji, H. and Sasakawa, M. (1984) Sex allocation and the effects of superparasitism on secondary sex ratios in the gregarious parasitoid, Trichogramma chilonis (Hymenoptera: Trichogrammatidae). Anim. Behav. 32, 478484.CrossRefGoogle Scholar
Tripathi, R. N. and Singh, R. (1991) Progeny and sex allocation by an aphidiid parasitoid Lysiphlebia mirzai (Hymenoptera: Aphidiidae) at different parasitoid-host ratios. Entomol. Gen. 16, 2330.CrossRefGoogle Scholar
Viktorov, G. A. and Kochetova, N. I. (1973) The role of trace pheromones in regulating sex ratio in Trissolcus grandis (Hymenoptera: Scelionidae). Zh. Obsch. Biol. 34, 559562.Google ScholarPubMed
Wylie, H. G. (1966) Some mechanisms that affect the sex ratio of Nasonia vitripennis (Walk.) (Hymenoptera: Pteromalidae) reared from superparasitised housefly pupae. Can. Entomol. 98, 645653.CrossRefGoogle Scholar
Wylie, H. G. (1973) Control of egg fertilisation by Nasonia vitripennis (Hymenoptera: Pteromalidae) when laying on parasitised housefly pupae. Can. Entomol. 105, 709718.CrossRefGoogle Scholar
Wylie, H. G. (1976) Interference among females of Nasonia vitripennis (Hymenoptera: Pteromalidae) and its effect on sex ratio of their progeny. Can. Entomol. 108, 655661.CrossRefGoogle Scholar