Systematic knowledge of the Neotropical Simuliidae

Systematic knowledge of the Neotropical Simuliidae has been accumulating quickly and there are 351 valid Neotropical species (Coscarón et al. 2008, Adler & Crosskey 2010, Hamada et al. 2010). Over the past 10 years, 67 taxonomic papers involving 20 researchers, as well as two extensive manuals, have been published (Coscarón & Coscarón-Arias 2007, Shelley et al. 2010), resulting in the description of 18 new species (Adler & Crosskey 2010, Hamada et al. 2010). Consequently, the Neotropical black fly became relatively well known and, unlike most of the other Neotropical animal taxa, a basic lack of data no longer is an issue (Rocha & Boerger 2009). Eleven subgenera of Simulium Latreille, 1802 have been found in the Neotropical Region (Adler & Crosskey 2010). Most of the species in these subgenera are well described and well represented in institutional collections. However, knowledge of supraspecific group relationships is very scarce and subgenera diagnoses are unsatisfactory. In addition, there are problems in the delimitation of the identity of some species. As a result of these problems, divergent systematic arrangements exist in the literature (Py-Daniel & Sampaio 1995, Coscarón et al. 2008, Adler & Crosskey 2010, Shelley et al. 2010) and loose synonymies of species are often proposed, which tend to appear and disappear in the literature. In the literature, all systematic decisions were made exclusively based on personal opinions, without any clear methodology or hypothesis; as a result, one cannot rationally reject or accept the changes proposed. There have been a few morphological phylogeny studies, but they have not targeted major subjects such as the monophyly of subgenera, the relationship amongst the subgenera or the species identity (e.g., Coscarón & Coscarón-Arias 1997, Strieder & Py-Daniel 2002). In addition, there are limited molecular, cytogenetic and morphometric works dealing with Neotropical taxa (e.g., Coscarón-Arias 1998, Scarpassa & Hamada 2003, Hamada et al. 2008, 2010). Therefore, the real problem underlying current Neotropical Simuliidae systematics is the organisation of the massive amount of data produced over the years. Simulium (Chirostilbia) Enderlein, 1921 is a good case study because it is a group endemic to the Neotropics and has remained taxonomically stable. For example, no researchers have ever questioned the monophyly of the group; however, as with the other subgenera, the position of the group within Simulium is unknown and the diagnoses made for this group are too broad and are inadequate to clearly identify the subgenus (Coscarón 1981, Coscarón & Coscarón-Arias 2007, Hernandez et al. 2008). In the present study, a cladistic analysis was performed to test the monophyly of Simulium (Chirostilbia) and to evaluate the phylogenetic structure within the subgenus. We also provide comments about the taxonomic problems of some species of Simulium (Chirostilbia).