A new species group in Megaselia, the lucifrons group, with description of a new species (Diptera, Phoridae).

Sibylle Häggqvist,Sven Olof Ulefors,Fredrik Ronquist

doi:10.3897/zookeys.512.9494

Abstract

With 1,400 described species, Megaselia is one of the most species-rich genera in the animal kingdom, and at the same time one of the least studied. An important obstacle to taxonomic progress is the lack of knowledge concerning the phylogenetic structure within the genus. Classification of Megaselia at the level of subgenus is incomplete although Schmitz addressed several groups of species in a series of monographs published from 1956 to 1981. Another problem is the lack of molecular phylogenetic analyses to support morphology-based conclusions. As a contribution towards addressing these problems, we here circumscribe a previously unrecognized monophyletic lineage of Megaselia consisting of species similar to Megaselia lucifrons. We base this taxonomic decision on morphological study of an extensive phorid material from Sweden, complemented by molecular analyses of select exemplars using two markers (COI and 28S). We name the clade the lucifrons species group, and show that it contains three distinct species. Our results also demonstrate that Megaselia subnitida Lundbeck, 1920, previously treated as a synonym of Megaselia lucifrons Schmitz, 1918, is a separate species, and we remove it from synonymy. The third species in the group was previously unknown; we describe it here as Megaselia albalucifrons sp. n.

Highlights

The Phoridae (Diptera), or scuttle flies, are one of the most diverse families of flies
We have identified approximately 65 species groups within Megaselia based on morphological characters
To encourage additional taxonomic and systematic investigations of Megaselia, we believe it is important to study its phylogenetic structure so that it can be broken down into smaller, natural groups suitable for more detailed study. It will be some time before a clear picture of the deep phylogenetic structure of the entire genus will emerge, whose sufficiently broad sampling of lineages supports a stable subgeneric classification of the genus

Summary

Introduction

The Phoridae (Diptera), or scuttle flies, are one of the most diverse families of flies. Megaselia is by far the largest genus in the family, a truly impressive radiation. With approximately 1,400 described species so far (Disney 2006), and many more expected, it might be the largest genus in the animal kingdom. It is apparently a fairly recent radiation; the oldest confirmed specimens of Megaselia do not show up in the fossil record until approximately 23 Myr from Dominican amber (Brown 1999), whereas the oldest fossil specimens from stem-group Phoridae are approximately 100 Myr, from the Cretaceous (Grimaldi and Cumming 1999)

Methods

Results

Conclusion