Fernando Farache (Univ. São Paulo) is back in CBGP for one year as a postdoctoral fellow and will be supervised by J.Y. Rasplus and A. Cruaud. He will study the genera Pegoscapus (pollinators of Ficus section Americana) and Idarnes (phytophagous/kleptoparasite wasps associated with these trees).
We will use the high diversity of species belonging to these two neotropical groups (several hundred species) that we already sampled. We plan to reconstruct a phylogenetic hypothesis for Pegoscapus using ultra-conserved elements (UCE) and will use the multigene hypothesis that was achieved during Fernando's PhD on Idarnes.
On a limited sampling, the genus Pegoscapus (Agaonidae) exhibits the higher number of lateral tranfers of pollinators among fig trees. Thus the co-diversification with their fig hosts appears less significant. We will seek to determine if this feature is still observed on a wider sampling. Our first results show that some clades remain associated with closely related fig trees, while other clades pollinate phylogenetically distant fig trees.
Idarnes are divided into three groups, exploiting fig flowers in different ways:
- a group of gall insects laying eggs before pollination,
- a group of late gallers exploiting flowers before or shortly after pollination,
- a group of kleptoparasitic wasps exploiting flowers that the pollinator or other wasps previously galled.
These groups show different levels of specificity, and gallers appear globally more specific than kleptoparasites.
From rebuilt phylogenies we will:
- analyse the relative impact of niche conservatism and host transfer on the diversification of these phytophagous/parasitic groups,
- study the influence of main features of the host plants (fig size, wall thickness, niche, spatial and altitude distribution) on hostshift success,
- compare the diversification patterns between Pegoscapus and Idarnes.
Finally, this work will encompass the revision of the genus Pegoscapus which includes a hundred species.