, Volume 83, Issue 3, pp 414–419 | Cite as

Parasitism rates and sex ratios of a parasitoid wasp: effects of herbivore and plant quality

  • Laurel R. Fox
  • Deborah K. Letourneau
  • Jamin Eisenbach
  • Saskya Van Nouhuys
Original Papers


We studied interactions among collards, Brassica oleracea var. acephala, the diamondback moth (DBM), Plutella xylostella (Lepidoptera: Yponomeutidae) and its parasitoid Diadegma insulare (Hymenoptera: Ichneumonidae) by manipulating plant nitrogen (N) concentrations in field and laboratory experiments. Parasitoid abundance strongly reflected DBM abundance and was related to total leaf N. Parasitism rates were high (70.7%) and density-independent. Wasp sex ratios varied markedly (3–93% female) in response to the herbivores, the plants, or both. Higher proportions of female wasps emerged from DBM larvae on plants with high leaf N than on unfertilized plants. More female wasps also emerged from larvae parasitized as larger instars. We suggest that wasps have the potential to control DBM populations through long-term numerical responses mediated by variable sex ratios.

Key words

Sex ratio Host-parasitoid interactions Nitrogen Plutella xylostella Diadegma insulare Brassica oleracea var. acephala 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Allen SE (ed) (1974) Chemical Analysis of Ecological Materials. Wiley, New YorkGoogle Scholar
  2. Anderson RM, May RM (1978) Regulation and stability of hostparasite interactions. I. Regulatory processes. J Anim Ecol 47:219–247Google Scholar
  3. Barbosa P (1988) Natural enemies and herbivore-plant interactions: influence of plant allelochemicals and host specificity. In: Barbosa P, Letourneau DK (eds) Novel Aspects of Insect-Plant Interactions. Wiley, NY, pp 201–229Google Scholar
  4. Barbosa P, Saunders JA (1985) Plant allelochemicals: linkages between herbivores and their natural enemies. In: Cooper-Driver GA, Swain T, Conn EE (eds) Chemically Mediated Interactions between Plants and other Organisms, Plenum, NY, pp 107–137Google Scholar
  5. Bouletreau M (1976) Influence de la photoperiode subie par les adultes sur la sex ratio de la descendance chez Pteromalus puparum (Hymenoptera; Chalcididae). Entomol Exp Appl 19:197–204Google Scholar
  6. Bull JJ (1983) Evolution of Sex Determining Mechanisms. Benjamin-Cummings, Menlo Park CAGoogle Scholar
  7. Campbell BC, Duffey SF (1979) Tomatine and parasitic wasps: potential incompatibility of plant antibiosis with biological control. Science 20:700–702Google Scholar
  8. Campbell BC, Duffey SF (1981) Alleviation of tomatine induced toxicity to the parasitoid, Hyposoter exiguae by phytosterols in the diet of the host, Heliothis zea. J Chem Ecol 7:927–946Google Scholar
  9. Charnov EL (1979) The genetical evolution of patterns of sexuality: Darwinian fitness. Am Nat 113:465–480Google Scholar
  10. Charnov EL (1982) The Theory of Sex Allocation. Princeton University Press, Princeton NJGoogle Scholar
  11. Charnov EL, Skinner SW (1984) Evolution of host selection and clutch size in parasitoid wasps. Florida Entomol 67:5–21Google Scholar
  12. Charnov EL, Hartogh RL, Jones WT, Assem J van den (1981) Sex ratio evolution in a variable environment. Nature 289:27–33Google Scholar
  13. Chua TH, Ooi PAC (1986) Evaluation of three parasites in the biological control of diamondback moth in the Cameron Highlands, Malaysia. In: Talekar NS (ed), Diamondback Moth Management. Proc. First Intl Workshop, Asian Vegetable Research and Development Center. Shan-hua, Taiwan, pp 173–184Google Scholar
  14. Clarke C (1984) Upsets in the sex-ratio of some Lepidoptera. In: Vane-Wright RI, Ackery PR (eds) The Biology of Butterflies. Academic Press, Orlando FL, pp 255–258Google Scholar
  15. Comins HN, Wellings PW (1985) Density-related parasitoid sexratio: influence on host-parasitoid dynamics. J Anim Ecol 54:583–594Google Scholar
  16. Compton SJ, Jones CG (1985) Mechanism of dye response and interface in the Bradford protein assay. Anal Biochem 151:369–374Google Scholar
  17. Fischlin A, Baltensweiler W (1979) Systems analysis of the larch bud moth system. Part I: The larch-larch bud moth relationship. Mitt Schweiz Entomol Ges 52:273–289Google Scholar
  18. Goodwin S (1979) Changes in numbers in the parasitoid complex associated with the diamond-back moth, Plutella xylostella (L.) (Lepidoptera). Aust J Zool 27:981–989Google Scholar
  19. Hamilton WD (1967) Extraordinary sex ratios. Science 156:477–488Google Scholar
  20. Harcourt DG (1963) Mortality factors in the population dynamics of the diamondback moth, Plutella maculipennis (Curt.) (Lepidoptera: Plutellidae). Mem Entomol Soc Canada 32:55–66Google Scholar
  21. Harcourt DG (1986) Population dynamics of the diamondback moth in southern Ontario. In: Talekar NS (ed), Diamondback Moth Management. Proc. First Intl Workshop, Asian Vegetable Research and Development Center. Shan-hua, Taiwan, pp 1–15Google Scholar
  22. Hassell MP (1978) The Dynamics of Arthropod Predator-Prey Systems. Princeton University Press, Princeton, NJGoogle Scholar
  23. Hassell MP (1986) Parasitoids and population regulation. In: Waage J, Greathead D (eds). Insect Parasitoids. Academic Press, Orlando FL, pp 201–224Google Scholar
  24. Hassell MP, Waage JK (1984) Host-parasitoid population interactions. Ann Rev Entomol 29:89–114Google Scholar
  25. Hassell MP, Waage JK, May RM (1983) Variable parasitoid sex ratios and their effect on host-parasitoid dynamics. J Anim Ecol 52:889–904Google Scholar
  26. Horn DJ (1987) Vegetational background and parasitism of larval diamond-back moths on collards. Ent Exp Appl 43:300–303Google Scholar
  27. Kfir R, Luck RF (1979) Effects of constant and variable temperature extremes on sex ratio and progeny production by Aphytis melinus and A. lingnanensis (Hymenoptera: Aphelinidae). Ecol Entomol 4:335–344Google Scholar
  28. King BH (1989) Host-size-dependent sex ratios among parasitoid wasps: does host growth matter? Oecologia 78:420–426Google Scholar
  29. Letourneau DK, Fox LR (1989) Effects of nitrogen and parasitism of lepidopterous larvae on cabbage butterflies. Oecologia 80:211–214Google Scholar
  30. Luck RF, Podoler H (1985) Competitive exclusion of Aphytis lingnanensis by A. melinus: potential role of host size. Ecology 66:904–913Google Scholar
  31. May RM, Anderson RM (1978) Regulation and stability of hostparasite interactions. II. Destabilizing processes. J Anim Ecol 47:249–267Google Scholar
  32. Murdoch WW (1979) Predation and the dynamics of prey populations. Fortschr Zool 25:295–310Google Scholar
  33. Murdoch WW, Stewart-Oaten A (1989) Aggregation by parasitoids and predators: effects on equilibrium and stability. Am Nat 134:288–310Google Scholar
  34. Murdoch WW, Reeve JD, Huffaker CB, Kennett CE (1984) Biological control of scale insects and ecological theory. Am Nat 123:377–392Google Scholar
  35. Murdoch WW, Chesson J, Chesson P (1985) Biological control in theory and practice. Am Nat 125:344–366Google Scholar
  36. Nunney L, Luck RF (1988) Factors influencing the optimum sex ratio in a structured population. Theor Pop Bio 33:1–30Google Scholar
  37. Orion (1986) Model 93–07. Nitrate Electrode Instruction Manual. Orion Research, Inc.Google Scholar
  38. Porter K (1984) Sunshine, sex ratio and behaviour of Euphydryas aurinia larvae. In: Vane-Wright RI, Ackery PR (eds), The Biology of Butterflies. Academic Press, Orlando FL, pp 309–311Google Scholar
  39. Reeve JD, Murdoch WW (1985) Aggregation by parasitoids in the successful control of the California red scale: a test of theory. J Anim Ecol 54:797–816Google Scholar
  40. SAS (1988) SAS/STAT Guide for Personal Computers. Version 6 editionGoogle Scholar
  41. Sokal RR, Rohlf FJ (1981) Biometry. 2nd edition, Freeman & Co. San Francisco CAGoogle Scholar
  42. Southwood TR, Comins HN (1976) A synoptic population model. J Anim Ecol 45:949–965Google Scholar
  43. Strong DR (1984) Density-vague ecology and liberal population regulation in insects. In: Price PW, Slobodchikoff CN, Gaud WS (eds), A New Ecology: Novel Approaches to Interactive Systems. Wiley, New York, pp 313–327Google Scholar
  44. Strong DR (1986) Density vagueness: abiding the variance in the demography of real populations. In: Diamond J, Case TJ (eds), Community Biology. Harper & Row, New York, pp 257–268Google Scholar
  45. Vinson SB (1981) Habitat location. In: Nordlund DA, Jones RL, Lewis WJ (eds) Semiochemicals: Their Role in Pest Control, Wiley, New York, pp 51–77Google Scholar
  46. Vinson SB, Iwantsch GF (1980) Host suitability for insect parasitoids. Ann Rev Entomol 25:397–419Google Scholar
  47. Waage JK (1982a) Sib-mating and sex ratio strategies in scelionid wasps. Ecol Entomol 7:103–112Google Scholar
  48. Waage JK (1982b) Sex ratio and population dynamics of natural enemies — some possible interactions. Ann Appl Biol 101:159–164Google Scholar
  49. Waage JK (1983) Aggregation in field parasitoid populations: foraging time allocation by a population of Diadegma (Hymenoptera, Ichneumonidae). Ecol Entomol 8:447–453Google Scholar
  50. Waage JK (1986) Family planning in parasitoids: adaptive patterns of progeny and sex allocation. In: Waage J, Greathead D (eds), Insect Parasitoids. Academic Press, Orlando, FL, pp 63–95Google Scholar
  51. Walde SJ, Murdoch WW (1988) Spatial density dependence in parasitoids. Ann Rev Entomol 33:441–466Google Scholar
  52. Walker TJ (1984) Do populations self-regulate? In: Huffaker B, Rabb RL (eds), Ecological Entomology, Wiley, New York, pp 531–558Google Scholar
  53. Werren JH (1984) A model for sex ratio selection in parasitic wasps: local mate competition and host quality effects. Neth J Zool 34:81–96Google Scholar
  54. Werren JH, Skinner SW, Huger AH (1986) Male-killing bacteria in a parasitic wasp. Science 231:990–992Google Scholar
  55. Williams HJ, Elzen GH, Vinson SB (1988) Parasitoid-host plant interactions emphasizing cotton (Gossypium). In: Barbosa P, Letourneau DK (eds) Novel Aspects of Insect-Plant Interactions. Wiley, NY, pp 171–200Google Scholar

Copyright information

© Springer-Verlag 1990

Authors and Affiliations

  • Laurel R. Fox
    • 1
  • Deborah K. Letourneau
    • 2
  • Jamin Eisenbach
    • 1
  • Saskya Van Nouhuys
    • 1
  1. 1.Department of BiologyUniversity of CaliforniaSanta CruzUSA
  2. 2.Environmental Studies BoardUniversity of CaliforniaSanta CruzUSA

Personalised recommendations