Oecologia

, Volume 47, Issue 1, pp 16–21 | Cite as

Is the insect or the plant the driving force in the cinnabar moth — Tansy ragwort system?

  • Judith H. Myers
Article

Summary

The interactions between cinnabar moth, Tyria jacobaeae L. and its food plant, tansy ragwort, Senecio jacobaea L. were studied for 4 to 6 years at 9 sites in North America to assess if the herbivore drove the dynamics of the plants or if the plants determined the dynamics of the insects. Cinnabar moth larval density is not closely related to changes in the size and spacing of tansy ragwort plants although high densities of larvae were associated with a high proportion of rosettes the next year. Fluctuating moth populations live in areas where rosettes are small, closely spaced and numerous compared to flowering stem plants. This situation is also associated with greater larval dispersal which may lead to over exploitation of the food supply. The coefficient of variation of both the size of rosettes and the distance between clumps of plants is associated with the coefficient of variation in moth density. This suggests that the plants may be driving the dynamics of the insect populations. The size of the moth egg batches is correlated to the size of the flowering stem plants in the previous year, indicating an adjustment between moth fecundity and food plant size. The conclusion is that environmental factors such as weather and soil type determine to a large degree the characteristics and variation in the plant populations and this in turn controls the dynamics of the insects. The relation of this situation to the biological control of weeds is discussed.

Keywords

Environmental Factor North America Soil Type Biological Control Food Supply 

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References

  1. Dempster JP (1971a) The population ecology of the cinnabar moth, Tyria jacobaeae L. (Lepidoptera, Arctiidae). Oecologia (Berl.) 7:26–67Google Scholar
  2. Dempster JP (1971b) A population study of the cinnabar moth, Tyria (Callimorpha) jacobaeae L. In: PJ den Boer and GR Gradwell (eds) Proc Adv Study Inst Dynamics Numbers Popul. p 380–389Google Scholar
  3. Dempster JP (1975) Animal Population Ecology. Academic Press LondonGoogle Scholar
  4. Dempster JP, Lakhani KH (1979) A population model for cinnabar moth and its food plant, ragwort. J anim Ecol 48:143–164Google Scholar
  5. Green WQ (1974) An antagonistic host/plant system: The problem of persistence. Ph.D. Thesis, Department of Zoology, Univ. British Columbia pp 247Google Scholar
  6. Hawkes RB (1973) Natural mortality of cinnabar moth in California. Ann Entomol Soc Am 66:137–146Google Scholar
  7. Hawkes RB, Johnson GR (1978) Longitarsus jacobaeae aids moth in the biological control of tansy ragwort. Proc 4th Int Symp Bio Control of Weeds, TE Freeman, (ed) 193–196Google Scholar
  8. Harris P, Wilkinson ATS, Thompson LS, Neary M (1978a) Reproductive biology of tansy ragwort, climate, and biological control by the cinnabar moth in Canada. Proc 4th Int Symp Biol Control of Weeds, TE Freeman (ed), p 163–173Google Scholar
  9. Harris P, Wilkinson ATS, Thompson LS, Neary M (1978b) Interaction between the cinnabar moth, Tyria jacobaeae L. (Lep.: Arctiidae) and ragwort, Senecio jacobaea L. (Compositae) in Canada. Proc 4th Int Symp Biol Control of Weeds, TE Freeman (ed), p 174–180Google Scholar
  10. Kitching RL (1976) Animal population ecology — a personal viewpoint. Ecology 57:830–831Google Scholar
  11. Meijden E van der (1971) Senecio and Tyria (Callimorpha) in a Dutch dune area. In: PJ den Boer and GR Gradwell (eds) Proc Adv Study Inst Dynamics Numbers Popul. p 390–404Google Scholar
  12. Meijden E van der (1976) Changes in the distribution pattern of Tyria jacobaeae during the larval period. Neth J Zool 26:136–161Google Scholar
  13. Meijden E van der (1979) Herbivore exploitation of a fugitive plant species: local survival and extinction of the cinnabar moth and ragwort in a heterogeneous environment. Oecologia (Berl) 42:307–323Google Scholar
  14. Myers JH (1976) Distribution and dispersal in populations capable of resource depletion: a simulation model. Oecologia (Berl), 23:255–269Google Scholar
  15. Myers JH (1978a) Biological control introductions as grandiose field experiments: adaptations of the cinnabar moth to new surroundings. Proc 4th Int Symp Biol Control of Weeds, TE Freeman (ed), p 181–188Google Scholar
  16. Myers JH (1978b) Selecting a measure of dispersion. Envir Entomol 7:619–621Google Scholar
  17. Myers JH (1979) The effects of food quantitiy and quality on emergence time in the cinnabar moth. Can J Zool 57:1150–1156Google Scholar
  18. Myers JH, Campbell BJ (1976a) Distribution and dispersal in populations capable of resource depletion: a field study on cinnabar moth. Oecologia (Berl), 24:7–20Google Scholar
  19. Myers JH, Campbell BJ (1976b) Indirect measures of larval dispersal tendency in the cinnabar moth, Tyria jacobaeae. Can Ent 108:967–972Google Scholar
  20. Myers JH, Post B Plant nitrogen and insect population fluctuations: a test with the cinnabar moth-tansy ragwort system. (MS in prep)Google Scholar
  21. Nagel WP, Isaacson DL (1974) Tyria jacobaeae and tansy ragwort in western Oregon. J Econ Ent 67:494–496Google Scholar
  22. Richards LJ, Myers JH (1980) Maternal influences on size and emergence time of the cinnabar moth. Can J Zool 58: In PressGoogle Scholar
  23. Varley GC, Gradwell GR, Hassell MP (1973) Insect Population Ecology: An Analytical Approach. Blackwell Scientific Publications. Oxford p 212Google Scholar

Copyright information

© Springer-Verlag 1980

Authors and Affiliations

  • Judith H. Myers
    • 1
    • 2
  1. 1.Institute of Animal Resource EcologyUniversity of British ColumbiaVancouverCanada
  2. 2.Department of Plant ScienceUniversity of British ColumbiaVancouverCanada

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