The Role Of Semiochemicals On Regulating Intraspecific Competition Of Fig Wasp Of Ficus Racemosa

Intraspecific competition for mating opportunities, oviposition sites and food resources is ubiquitous for insects. Semiochemicals-based chemical communications may be vital in the regulation of intraspecific competition. The finding show that interference and intraspecific competition for fighting for limited female flowers resources (for pollinating and oviposition) among individuals of pollinating fig wasps(Ceratosolen fusciceps) of Ficus racemosa occur when the number of wasp introduced into fig is more than3according to Wang et al report, in order to investigate whether the chemical communication based on semiochemicals can regulate the intraspecific competition of wasp, we extracted, isolated, and identified the volatile organic compounds (VOCs) of the wasps and fig in two groups, before the wasps were introduced into the syconium and after, by HS-SPME (head space solid-phase micro-extraction) and GC-MS (gas chromatography coupled with mass spectrum), then identified the differences of VOCs in two groups, finally evaluated the anti-oviposition activity of the VOCs and the survival analysis experiment was carried out in which we verify whether the VOC can affect the longevity of wasp. The results showed that the wasp secrete methyl linolenate when there is intraspecific competition among wasps in fig-pollinating wasp system. As a biological activity compound, methyl linolenate can’t significantly affect the longevity of wasp, but it can deter the pollination and oviposition behavior of wasps, and reduce the amount of galls, seeds and the density of offspring. Thus, wasp and fig can avoid excessive intraspecific competition for short supply resources, the results reduce the competition pressure of offspring and improve the fitness. Thereby, methyl linolenate which has potential function of chemical communication plays an important role in regulating intraspecific competition of wasp.