Speciose nonpollinating wasp community and parasitic pressure: crops without pollinators in figs of Ficus subpisocarpa

Abstract

Wasp communities are often complex and speciose and often associated with plant and herbivorous hosts. Nonpollinating wasps are one example of these communities: these communities can reach 20 species on a single species of Ficus trees. Such diversity implies that the number of interactions is high, and the trophic web may be complicated to disentangle. Some of wasp species may be gall wasps whereas the majority of them are parasitoid wasps feeding on other wasp species larvae. To understand the nonpollinating fig wasp community associated with Ficus subpisocarpa in Northern Taiwan, the oviposition timing of the fig wasps has been monitored and a bagging experiment has been done on several crops. Twenty-one morphospecies were found, and three fig crops type were defined by the wasp composition and fig traits as “typical” crops, “rare NPFWs” crops (RN), and “rare pollinators” (RP) crops. The diversity indexes showed that the typical type has the highest diversity and the RN type, which is the most dissimilar crop from the others, has the lowest diversity. From their oviposition time along the fig development, the nonpollinating fig wasps can be easily divided into two guilds: gall wasps and parasitoid wasps. Moreover, one of the most striking results of this study is the presence of figs that do not produce any pollinator in RP crops. The implications of this type of crops on the mutualism between Ficus subpisocarpa and its pollinator are discussed.