Low Sampling Effort and High Genetic Isolation Contribute to Underdocumented Diversity in Philippine Fig Wasps

Abstract

One of the unique attributes of tropical forests is the diversity of fig-fig wasp interactions. In the Philippines, there is a good estimate of the number of fig species, but none for the pollinating fig wasps. According to our review of the literature, there are only 10 described species of Ceratosolen in the Philippines, eight of which are endemic to the country (80% endemicity) out of a global count of 72 species worldwide. However, most historical collections were only from Luzon island. In this study, because of an increased sampling effort across 10 islands – coupled with morphological comparisons with described species and analysis of genomic data – we identified 29 as yet undescribed Ceratosolen species (which represents an increase of nearly 300% for the Philippine fig wasp fauna). This shows that the major factors contributing to under-documented diversity in Philippine Ceratosolen are low sampling effort and high genetic isolation between lineages. More importantly, this is probably not limited to fig wasps and we suspect underestimated diversity in most Philippine faunal lineages. Building a strong taxonomic foundation is key to the establishment of good conservation practices. It is time to start investing in Philippine biodiversity research before we lose our natural treasures.