Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (4): 768-775.DOI: 10.3773/j.issn.1005-264x.2008.04.005

• Original article • Previous Articles     Next Articles

COEVOLUTION BETWEEN TWO INTERNAL OVIPOSITING FIG WASPS AND HOST FICUS CURTIPES

ZHANG Feng-Ping1,2, PENG Yan-Qiong1, YANG Da-Rong1,*()   

  1. 1Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China
    2Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2007-12-13 Accepted:2008-03-28 Online:2008-12-13 Published:2008-07-30
  • Contact: YANG Da-Rong

Abstract:

AimsFig trees (Ficus) and their pollinating wasps (Chalcidoidea, Agaonidae) form a highly obligated mutualism. In addition, Ficus species also host some non-pollinating fig wasps, most of which oviposit from the outside of figs, and only a few have evolved fig-entry behavior. Ficus curtipes hosts an internal ovipositing non-ollinating fig wasp, Diaziella yangi, in Xishuangbanna, and it is similar to the pollinating fig wasp (Eupristina sp.). Our objective was to investigate whether there was coevolution between D. yangi and host F. curtipes in aspects of morphology, behavior and ecology.

Methods Head length and width of the fig wasps, along with length of the ovipositors and styles, were measured using dissecting microscopy. In the field, the behavior of wasp’s entry in female floral phase was observed, and the mating and emerging behavior in male floral phase were observed in the laboratory. Moreover, we recorded a number of foundress in the fig female floral phase, and counted the number of wasps and seeds in the male floral phase.

Important findings The head shape (length:width) of female D. yangi was strongly correlated with that of the female pollinator Eupristina sp., while there was no corresponding correlation in male head shape. The style-length of figs was in the reach ofEupristinasp. and D.yangi. The emergence time for each Eupristina sp. from a gall was usually for 3-5 h, and the mating time lasted 17-19 min. The emergence time for each D. yangi was usually for 18-20 min, and the mating time lasted 20-30 s. In nature, almost 90% of figs at female floral phase averaged only one D. yangi and one Eupristina sp. In the natural community, D. yangi has a significant negative effect on the pollinator, but a positive effect on the number of viable seeds. Both internal ovipositing species entered fig in the same day of female floral phase and left the fig at the same time (figs’ male floral phase). Results suggested thatD.yangi can pollinate the figs, similar to the pollinator Eupristinasp. It has high degree of co-adaptation with the hostF. curtipes. This is possibly an example of evolving from parasitism to mutualism.

Key words: Ficus curtipes, Eupristina sp., Diaziella yangi, coevolution