Phylogeny of the genus Scathophaga (Diptera : Scathophagidae) inferred from mitochondrial DNA sequences

Scathophaga stercoraria has been used for a large number of studies in anim al ecology and evolution. Morphological phylogenetic work on the relationsh ips among flies of the family Scathophagidae in general, and the genus Scat hophaga in particular, has led to limited or incomplete conclusions. We add ressed these relationships by sequencing 810 base pairs (bp) from the mitoc hondrial cytochrome oxidase subunit I (COI) gene and 738 bp of the mitochon drial cytochrome b (Cyt b) gene in 16 species of Scathophagidae. Phylogenet ic analysis of these two protein-coding genes allows us to resolve relative ly well the relationships within the genus Scathophaga, using both separate and combined (COI + Cyt b) data. Most of the phylogenetic trees generated by our data support the following relationships: (((S. analis + S. inquinat a) + S. lutaria) + S. cineraria + (S. taeniopa + S. suilla + S. incola) + S . furcata + S. tropicalis). The most noteworthy findings are that (i) S. ob scura and S. tinctinervis, which were formerly placed in the genus Conioste rnum, form a sibling species cluster; (ii) S. taeniopa and S. suilla, which are morphologically very similar species, are clearly distinct taxa; (iii) S. analis, considered a doubtful species in the Catalogue of Palearctic Di ptera, could be a synonym of S. inquinata; and (iv) the South American S. t ropicalis and the Old World S. stercoraria are not sister-species.