Sexual differences in the attractiveness of figs to pollinators: females stay attractive for longer

Authors

  • NAZIA SULEMAN,

    1. Faculty of Biological Sciences, University of Leeds, Leeds, U.K.
    Search for more papers by this author
    • Current address: Plant Protection Division, Nuclear Institute of Agriculture (NIA), Tando Jam 70060, Pakistan.

  • SHAZIA RAJA,

    1. Faculty of Biological Sciences, University of Leeds, Leeds, U.K.
    Search for more papers by this author
    • The Institute of Plant and Environmental Protection, National Agriculture Research Centre (NARC), Park Road, Islamabad 44000, Pakistan.

  • YUAN ZHANG,

    1. Key Laboratory of Tropical Forest Ecology, Chinese Academy of Sciences, Kunming, China
    2. Graduate University of the Chinese Academy of Science, Beijing, China
    Search for more papers by this author
  • STEPHEN G. COMPTON

    Corresponding author
    1. Faculty of Biological Sciences, University of Leeds, Leeds, U.K.
    Search for more papers by this author

Stephen G. Compton, Faculty of Biological Sciences, Institute of Integrative and Comparative Biology, University of Leeds, Leeds LS2 9JT, U.K. E-mail: S.G.A.Compton@leeds.ac.uk

Abstract

1. Figs on male dioecious fig trees (Ficus, Moraceae) are breeding sites for pollinator fig wasps (Hymenoptera, Agaonidae), but figs on female plants are traps that produce only seeds. As the short-lived fig wasps cannot reproduce in female figs, natural selection should favour individuals that avoid them. Several studies have failed to detect such discrimination, a result attributed to inter-sexual mimicry and ‘selection to rush’ in the wasps, but their experiments failed to explicitly take into account fig age (how long they had been waiting to be pollinated).

2. We compared the relative attraction of male and female figs of known ages of the South East Asian Ficus montana Burm. f. to its pollina tor Liporrhopalum tentacularis Grandi and examined how the reproductive success of the plant and its pollinator change with the age of the figs.

3. Mean retention time for un-pollinated figs on female plants was 16 days whereas in male figs it was 12 days. Female figs remained attractive for up to 2 weeks, although the wasps were less willing to enter older figs. After pollinator entry, receptivity continued for several days, lasting longer in figs entered by a single wasp. Consistent with abortion rates, attractiveness persisted longer in female figs. Older figs produced fewer fig wasp offspring, but similar numbers of seeds.

4. The sexual differences in floral longevity in F. montana may represent part of a previously un-recognised reproductive strategy in some fig trees that allows male plants to ‘export’ pollinators while also maintaining a resident fig wasp population.

Ancillary