Biodiv Sci ›› 2014, Vol. 22 ›› Issue (2): 189-195.DOI: 10.3724/SP.J.1003.2014.13238

• Orginal Article • Previous Articles     Next Articles

Roles of semiochemicals in regulating intraspecific competition of pollinating wasps of Ficus racemosa

Xiangzong Geng1,2, Bo Wang2, Aiqun Jia1,*(), Ruiwu Wang2,*()   

  1. 1 School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094
    2 Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223
  • Received:2013-11-08 Accepted:2014-03-16 Online:2014-03-20 Published:2014-04-03
  • Contact: Jia Aiqun,Wang Ruiwu

Abstract:

Intraspecific competition for mating opportunities, oviposition sites, and food resources is ubiquitous for insects. Semiochemical-based chemical communication may play important roles in the regulation of intraspecific competition. The aims of this study are (1) to investigate the possible occurrence of intraspecific competition among individuals of pollinating fig wasps (Ceratosolen fusciceps) of Ficus racemosa with manipulative experiments, and (2) to assess the potential function of volatile organic compounds (VOCs) in regulating the behavior of fig wasps to avoid excessive competition using head space solid-phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). The results showed that wasps laid more eggs when they were introduced into the syconium sequentially, compared with simultaneously introduced wasps. A chemical analysis showed that the VOCs differed quantitatively and qualitatively. Several of the 22 identified VOCs functioned to deter oviposition in other insect species. Our results indicated that intraspecific competition at oviposition sites may occur among individuals of C. fusciceps and that semiochemicals may play important roles in regulating the oviposition behavior of this species. These factors could significantly affect the fitness of both fig wasps and the host fig.

Key words: Ficus racemosa, Ceratosolen fusciceps, intraspecific competition, HS-SPME & GC-MS, semiochemicals