Biodiv Sci ›› 2012, Vol. 20 ›› Issue (3): 324-329.DOI: 10.3724/SP.J.1003.2012.06012

Special Issue: 传粉生物学:理论探讨与初步实践

• Original Papers • Previous Articles     Next Articles

Convergence in host recognition behavior between obligate pollinating fig wasps and non-pollinating fig wasps

Ding Gu1,2, Yanqiong Peng1, Darong Yang1,*()   

  1. 1 Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Mengla, Yunnan 666303
    2 Graduate University of the Chinese Academy of Sciences, Beijing 100049
  • Received:2012-01-12 Accepted:2012-02-23 Online:2012-05-20 Published:2012-05-09
  • Contact: Darong Yang

Abstract:

The highly specific mutualism between fig trees and their obligate pollinating fig wasps is usually exploited by non-agaonid wasps, and some of these wasps can enter and pollinate the figs just like the obligate pollinating wasps. Therefore, the agaonid and non-agaonid wasps have convergently evolved in their morphological characteristics and phenology. However, there are few data about the convergence of host recognition behaviors among these wasps. In Ficus curtipes, there are three internally ovipositing wasps, i.e. one obligate pollinating wasp, Eupristina sp., and two inquiline wasps (Diaziella yangi and Lipothymus sp.), which can also pollinate the figs if they enter the figs. In this study, we carried out several behavioral experiments with a Y-tube olfactometer to test the hypothesis of convergence of host recognition behaviors among these wasps. We observed and recorded the wasps’ behavior of choice among figs at different developmental phases and among 6-methyl-5-hepten-2-ol, 6-methyl-5-hepten-2-one and the mixture of the two chemicals. Our results showed that all three of the wasps were significantly attracted by the receptive F. curtipes figs when presented with choices between receptive figs and figs at other developmental phases and were significantly repelled by the male phase figs of F. curtipes when presented with choices between male phase figs and figs at other developmental phases. In addition, all of them also preferred to the compound 6-methyl-5-hepten-2-ol at the dose level of 1µL. These results provide evidence for the hypothesis of convergence of host recognition behavior among obligate pollinating fig wasps and non-pollinating fig wasps. The role of behavioral convergence in the evolution of non-obligate pollinating wasps into obligate ones is also discussed.

Key words: Ficus, Agaonidae, Ficus curtipes, host recognition, behavioral convergence, obligate pollination system