Oecologia

, Volume 93, Issue 3, pp 367–373

Coin-flipping plasticity and prolonged diapause in insects: example of the chestnut weevil Curculio elephas (Coleoptera: Curculionidae)

Authors

  • F. Menu
    • URA CNRS 243, Biométrie, Génétique et Biologie des PopulationsUniversité Claude Bernard Lyon I
  • D. Debouzie
    • URA CNRS 243, Biométrie, Génétique et Biologie des PopulationsUniversité Claude Bernard Lyon I
Original Papers

DOI: 10.1007/BF00317880

Cite this article as:
Menu, F. & Debouzie, D. Oecologia (1993) 93: 367. doi:10.1007/BF00317880

Abstract

Spreading of emergence over several years due to prolonged diapause in some larvae was shown in the chestnut weevil. Depending on the year the larvae buried themselves in the ground, 32–56% of live adults emerged after 2 or 3 years of underground life. Variability in the duration of diapause was assumed to correspond to tactics of adaptative “coin-flipping” plasticity. This plasticity must allow the chestnut weevil to respond to the unpredictability of its habitat as measured by the irregularity of chestnut production and summer drought. Indeed, fecundity and adult longevity did not lessen after 2 years of underground life. No drastic decrease in the population size of weevils occurs after bad years; for instance when the number of chestnuts on the study tree is less than 10 000, passers-by can collect all the fruit and about 95% of larvae developing in chestnuts are destroyed. Diapause nature (simple or prolonged) may be related to moisture and gas rates in the ground from October to December. These factors acting in autumn are not known to be involved in the physiological mechanisms that control the production of chestnuts.

Key words

Demographic tacticsCoin-flipping plasticityProlonged diapauseInsect population dynamicsWeevil
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Copyright information

© Springer-Verlag 1993