Improving the taxon sampling for a phylogeny of Cladochaetini, focusing on Diathoneura Duda, 1924 and outgroups (Diptera: Drosophilidae)

Abstract

The tribe Cladochaetini is a particularly interesting clade of Drosophilidae from different perspectives. It presently includes two extant genera (Cladochaeta and Diathoneura) and one extinct genus (Myiomia). From an alpha-taxonomy point of view, it can be considered an "open-ended" taxon-with highly speciose "orphan taxa"-, often uncollected or unsorted, and without clear generic boundaries. From the point of view of natural history, it has some of the most interesting evolutionary questions in biology and behavior. One of its genera, Cladochaeta, is mainly an arthropod parasite, with some few species known to breed on flowers, while Diathoneura mainly breeds on flowers. It is quite likely that living in flowers is a groundplan feature in the tribe, but the shift from phytophagy to parasitism involves specialization not only of behavior, but also changes in digestive enzymes etc. Finally, from a phylogenetic perspective, the tribe has a complicated taxonomic history with phylogenetic implications. Not only there is still not a phylogeny for the genera, but the diagnosis of the genera overlap and is possible that Cladochaeta is nested within Diathoneura. There are additional problems concerning male and female terminalia sclerite homology. The solution of these problems will lead to a better understanding of the phylogenetic relationships within the tribe. This project has as its main goal to improve the taxonomic sampling of a phylogenetic study of the Cladochaetini basically with a wide approach to Diathoneura diversity, deepening the discussion and comprehension of the morphology, with the help of the knowledge of Dr. David Grimaldi, the most indicated researcher on the group. (AU)