Journal of Comparative Physiology A

, Volume 186, Issue 6, pp 567–574

Sex pheromone mimicry in the early spider orchid (Ophrys sphegodes): patterns of hydrocarbons as the key mechanism for pollination by sexual deception

  • F. P. Schiestl
  • M. Ayasse
  • H. F. Paulus
  • C. Löfstedt
  • B. S. Hansson
  • F. Ibarra
  • W. Francke
ORIGINAL PAPER

DOI: 10.1007/s003590000112

Cite this article as:
Schiestl, F., Ayasse, M., Paulus, H. et al. J Comp Physiol A (2000) 186: 567. doi:10.1007/s003590000112

Abstract

We investigated the female-produced sex pheromone of the solitary bee Andrena nigroaenea and compared it with floral scent of the sexually deceptive orchid Ophrys sphegodes which is pollinated by Andrena nigroaenea males. We identified physiologically and behaviorally active compounds by gas chromatography with electroantennographic detection, gas chromatography-mass spectrometry, and behavioral tests in the field. Dummies scented with cuticle extracts of virgin females or of O.sphegodes labellum extracts elicited significantly more male reactions than odorless dummies. Therefore, copulation behavior eliciting semiochemicals are located on the surface of the females' cuticle and the surface of the flowers. Within bee and orchid samples, n-alkanes and n-alkenes, aldehydes, esters, all-trans-farnesol and all-trans-farnesyl hexanoate triggered electroantennographic responses in male antennae. Most of the alkanes and alkenes occurred in similar patterns both in the bees and orchids. O.sphegodes leaf extracts contained mostly the same compounds but in different proportions. In behavioral tests with synthetic compounds, blends of alkenes triggered significantly more approaches and pounces of the males whereas alkanes were not more attractive than odorless dummies. Since alkanes and alkenes together were most attractive, we conclude they constitute the bees' sex pheromone as well as the pseudocopulation-behavior releasing orchid-odor bouquet.

Key wordsAndrena nigroaenea Sex pheromone Chemical mimicry Orchid pollination Wax compounds 

Copyright information

© Springer-Verlag Berlin Heidelberg 2000

Authors and Affiliations

  • F. P. Schiestl
    • 1
  • M. Ayasse
    • 1
  • H. F. Paulus
    • 1
  • C. Löfstedt
    • 2
  • B. S. Hansson
    • 2
  • F. Ibarra
    • 3
  • W. Francke
    • 3
  1. 1.Institute of Zoology, Department of Evolutionary Biology, Althanstr. 14, A-1090 Vienna, Austria e-mail: a8917722@unet.univie.ac.at Fax: +43-1-31336-778AT
  2. 2.Department of Ecology, Lund University, S-22362 Lund, SwedenSE
  3. 3.Department of Organic Chemistry, D-20146 Hamburg, GermanyDE

Personalised recommendations