165 INTRODUCTION Simulium Latreille, 1802, is the most speciose simuliid genus, comprising almost 75% of the described species of the family Simuliidae (Crosskey & Howard 1997). The genus occurs in all biogeo- graphical regions, although each subgenus is con- fined to one or more regions. The first uncontro- versial fossil assigned to the family is a member of the tribe Prosimuliini (sensu Currie 1988), from the Jurassic/Cretaceous transition, namely: Kovale- vimyia lacrimosa Kalugina, 1991, from Siberia (Currie & Grimaldi 2000). The oldest Southern Hemi- sphere fossil originates from the Cretaceous Koon- warra fossil beds of Australia (135 Mya), and Cross- key & Howard (1997) assigned this species to the African genus Paracnephia Rubtsov, 1962, indicat- ing a Gondwanian origin. Craig et al. (2001) presen- ted a biogeographic analysis of the subgenus S. (Inseliellum) Rubtsov, 1974, and suggested that Simulium ‘evolved’ prior to the separation of New Zealand from Australia/Antarctica (between 80-60 Mya). Crosskey (1990: 58) believed that the family was widespread in Pangea and dated the origin of the family to at least the early Jurassic (200-175 Mya). He considered, however, dispersal to be the main mechanism explaining the current distribution patterns of simuliid genera and subgenera without vicariance playing a crucial rôle. He also proposed that Antarctica would have been habitable by simuliids at that time, and therefore the continent could have acted as a bridge between Australia and New Zealand, and South America. Coscarón & Coscarón-Arias (1995) presented a preliminary biogeographical analysis of the neotropical simuliid fauna, delimiting 16 areas of endemism. These provinces, in a slightly modi- fied form, were later used in a biogeographical analysis by Miranda-Esquivel (2001). In that study, the rôle of dispersal in the distribution of neo- tropical simuliid subgenera was evaluated. Elimi- nating the commonest dispersal events, the gen- eral area cladogram was found to be congruent with terrestrial biota, where two sub-regions arise: the Neotropical Subregion sensu stricto (Cerrado, SE Brasil, Guyana and Amazonia, which is synony- mous with the Guyano-Brasilian Region of Jeannel (1942)), and the Andean Sub-region, which is equivalent to the Andean Region proposed by Morrone (1996). Pacifica and the Mesoamerican Mountains were placed apart from the main Neotropical Region clade (vide Figure 1). Miranda- Esquivel & Coscarón (submitted) present a pre- liminary attempt at a cladistic analysis of the genus at the subgeneric level for the Neotropical/Afro- tropical/Australian-oriental Regions. Distributional patterns of neotropical, afrotropical and Australian-oriental Simulium Latreille subgenera (Diptera: Simuliidae) Daniel Rafael Miranda-Esquivel 1 & Sixto Coscarón 2 1 Laboratorio de Sistemática y Biogeografía, Escuela de Biología, Universidad Industrial de Santander, A. A. 678, Bucaramanga, Colombia; e-mail: dmiranda@uis.edu.co 2 Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, Paseo del Bosque 1900, La Plata, Argentina; e-mail: sixtoco@museo.fcnym.unlp.edu.ar The historical biogeography of Simulium Latreille subgenera of the Neotropical, Afrotropical, and Australian-oriental Regions is reconstructed applying dispersal-vicariance analysis. The results suggest that the genus originated within an area represented by Pangea. This places the origin for the genus in the middle of the Jurassic Period (180-160 Mya). Cimbebasia 19: 165-174, 2003 Proceedings of the workshop ‘African Diptera Biogeography & Gondwanaland’, 5 th International Congress of Dipterology, Brisbane, Australia, 29 Sept. – 4 Oct. 2002.