The Primary Research of Sex Ratio Mechanism of Pollinating Fig Wasp in Ficus racemosa

Purpose Fig-pollinating wasp is one of the most well-known model animals to examine the sexual ratio regulation mechanism under the local mating competition and the inbreeding condition. Our aim was to learn more about the sex allocation strategy of fig wasp by foundress manipulating experiment.

Method We investigated the sex ratio, clutch size, broods size of offspring under different foundress density by controlling the number of foundress (1-12) in each syconium and analyzed the data with R.

Results The predicted sex ratio of wasp Ceratosolen fusciceps presented very close to the experiment result under the LMC and inbreeding theory. The predicted value was more consistent with the experiment sex ratio when using the molecular method to estimate the inbreeding coefficient (F=0.21) than using the average foundress number. The average male offspring number was significantly higher in the multiple foundress treatments than single foundress treatment but there was no difference between the multiple foundress treatments (foundress number varies from 3 to 12). As the increase of the foundress number, the average offspring per foundress (clutch size) decreases and there was a significant negative correlation between clutch size and sex ratio.

Conclusion LMC theory predicted the sex ratio adjustment mechanism of fig pollinating wasp C. fusciceps in Ficus racemosa basically. However, by comparing the quantitative LMC model prediction with the experimental results, it was found that there are still errors. We believed that there are two reason for the errors. One is the effect of inbreeding on fig wasp, the other is that there are different cues to assess potential LMC between single foundress or multiple foundress.