Simple SummaryNon-pollinating fig wasps (NPFWs) in the genusApocryptamostly interact with fig species belonging to the subgenusSycomorus. However, an instance of theApocryptaspecies associated withFicus pedunculosavar.mearnsiiin the subgenusFicuswas observed. To better understand its parasitism features, we inferred its life history with the fig growth and estimated the parasitism ability using a quantitative and qualitative approach that compared the ovipositor sheath-length ratio to the fig gall+wall thickness among the species inApocrypta. Our results showed that this wasp exhibited a high parasitism ability, more advantageous than that of other congeneric species. In contrast, its parasitism rate was low, suggesting that other ecological factors like oviposition strategy and the severe habitat could affect its efficiency. These findings may provide a reference for the symbiosis between fig trees and fig wasps.AbstractNon-pollinating fig wasps (NPFWs), particularly long-ovipositored Sycoryctina wasps, exhibit a high species specificity and exert complex ecological effects on the obligate mutualism between the plant genusFicusand pollinating fig wasps.Apocryptais a genus of NPFWs that mostly interacts with theFicusspecies under the subgenusSycomorus, and the symbiosis case betweenApocryptaandF. pedunculosavar.mearnsii, aFicusspecies under subgenusFicus, is unique. As fig’s internal environments and the wasp communities are distinct between the two subgenera, we addressed the following two questions: (1) Are the parasitism features of theApocryptawasp associated withF. pedunculosavar.mearnsiidifferent from those of other congeneric species? (2) Is thisApocryptaspecies an efficient wasp that lives in its unique host? Our observation revealed that this wasp is an endoparasitic idiobiont parasitoid, as most congeneric species are, but developed a relatively long ovipositor. Furthermore, the relationships of the parasitism rate versus the pollinator number, the fig wall, and the sex ratio of the pollinator, respectively, showed that it possessed a higher parasitism ability than that of other congeners. However, its parasitism rate was low, and thus it was not an efficient wasp in its habitat. This difference between parasitism ability and parasitism rate might be a consequence of its oviposition strategy and the severe habitat conditions. These findings may also provide insights into the mechanism to maintain the interaction between the fig tree and the fig wasp community.