Bioges@aaphied History of the Neotropied adNeantmctic Simuliidae (Diptera) 'Institute Argontino de Investigaciones de las Zonas Aridas (MIZA),Casilla Cai-reo 507,5500 Mendoza, Ar- gentina. zDepartamento Cientifico de Entomologia, Musea de La Plats, Paseo del Bosquc sin, 1900 1,a Plata, Buenos Aires, Argentina Ahtrack Using the lineages of taxa and their distribution on different areas of endcmism, and hy cladistic methodology appiiod to biogeography, we try to define the biutic history of the areas of endemism based on Neotropical and Neantarctic Simuliidae. Using tho information of the eladograms of nine Central and South American monophyletic supraspecific taxa of Simuliini and 16 areas of endeminm, we perform a Component Analysis with wmponent 1.5, using the assumption 2. A sccond analysis was mark using Biogeographic Parsi- mony Analysis; the data matrix was ilnalyzed with the prowam NONA. The ciadograms obtained show the pos- sible sequence of historic separation of areas of endemism, evidencing the presence of two large biota: tho aus- tral (Noantaretic) and the tropical (Neotropical),that were maintained in partial isolation. The areas of ende- inism of the austral biota are: Subantarctic. Central Chile. Pataeonian. Puna. Monte and Pamosm: those of the vicariant events that affocted the Simuiiiciae are sea inbvessions,iheemergence of the ~ndesand elimati~han&s. Key words: Neotropical Region, Neant,arctic Rcgion, blackflies, cladistic biogeography, areas of endernism, biogeographic history The similitude between hiotas from different This contribution uses the information avail- areas has called the attention of naturalists, who able on Simuliidae (Diptera). The Simuliidae is a have tried to explain their prohahie relations with well represented group in the Central and South a numher of hypotheses. Many of the hiogeo- America, with 12 genera and approximately 340 graphic schemes are based on the comparison species (Crosskey & Howard, 1997), most of which between different biotas of the world, proposing are endemic to this region (Coscarbn & Coscarbn dispersion hypotheses to explain the observed Arias, 1995). The Simuliidae occur in Central and similitude (Wallace, 1876; Simpson, 1964; South America from southern Mexico to Tierra Darlington, 1965; Raven & Axelrod, 1975). dei hego. They are distrihuted in a large num- The use of cladistic methodology in system- ber of environments rangingfrom sea level to 4700 atics (Hennig, 1965) and its application in hioge- meters of altitude. ography (Brundin, 1966; I-lennig & Wydozinsky, Numerous phylogenetic studies of the Cen- 1966; Rosen, 1978) have provided an operational tral and South American Simuliidae have been tool to analyze the distribution patterns (Platnick made in the last years (Coscarbn & Coscarbn- & Nelson, 1978; Nelson & Platnick, 1981; Arias, 1996,1997;Coscarbn & Miranda-Esquivel, I-Iumphries & Parenti, 1986). 1998; Coscarbn et al., 1996,19991, where possible Cladistic biogeography assumes a correspon- biogeographic infercnces are discussed for each dence between the phylogenetic relations of the one oithe groups analyzed. Coscarbn & Coscarbn- taxa and the relations of the areas they occupy, Arias (1995) identified the areas of endemism for and that organisms have evolved together with the Neotropical and Neantarctic Simuliidae the Earth. This would he why the "history of the which are used in this work, together with the areas of endemism" can he inferred startingfkom Simuliidae phylogenetic analyses, to obtain hy- the cladistic analyses of the several taxa com- potheses on the biogeographic history ofthis fam- posing a biota. ily in Central and South America. 120 Revista del Museo Argentina de Ci.encias Naturales, n. s. 3 12), 2001 MATERW AND METHODS in the humid galleries and piedmonts. It corre- sponds partly to the biogeographic provinces Selection of the areas named Sabana, Guajira, and Venezolana by The area under study comprises the Neotro- Cabrera and Willink (1980). Its their Pduna is pica1 Region and the Neantarctic Region of Cen- related to that of the Guiana and Uungas areas. tral and South America. These two regions are 4. Cerrado (CE):it is a large, diagonally dis- considered by many authors (Ringuelet, 1961; posed area in South America, located between Fittkau, 1969; Mkller, 1973) as only one region, Amazonia and the Mountains region of the Bra- the Neotrnpical. Nevertheless there are two bio- zilian southeast. It corresponds to what Cabrera tas with very dissimilar affinities (Jeannel, 1912; and Willink (1980) called Caatinga, Chaco, 1967; Monros, 1958; Kuschel, 1969; Lfalfter, Cerrado, and part of the Espinal. It is a tropical 1974; Porter, 1991; Roig-Juiient, 1992) which arid area with shrubby vegetation and xeric for- occupy areas that have been considered as dif- ests of Prosopis ('algarrobos') and Aspidosperma ferent biogeopraphic regions. One of them is the ('quehracho'). It constitutes a rich area of ende- tropical biota called Guiano-Brazilian (or rnism for insects (Roig-Jufient, 1998) related to Jeannei's Tnahresic, 1942, or Kuschel's Brasilic, the tropical fauna of Sgi~rthfunerica. 1.969) tha taxa of which are phylogenetically re- 5. Central Chile <%:II):iL includes the Chil- lated with other taxa from the tropical African can area from Coquimbc to Conception (between regions. Thc other biota in South America is the 30" and 37" S latitude), In its septentrional part Patagonian (or Jeannei's Paleantarctic, 2942, or the aridity conditions are higher (Coquimbo re- Monros' Neantarctic, 1958) with taxa more gion of Roig-Juiient, 1994), with small forests closely related to the taxa from other austra: along the creeks close to the coast. The areas, such as Australia, New Zealand, South meridionai part is characLerized by shrubby veg- Mrica, and numerous subantarctic islands. The etation (Cabrera & Wiliinh, 1980). Within this reson occupied by this austral biota of Soutlr Central Chilean area there are relicts of snban- America difSers greatly according to the differ- tarctic forests lilt. Campana) showing that the ent authors. Monriis (1958) considered only the Antardandean forest was much more extended. area occupied by Nolhofagus forests. Most of the 6. Desert (DE): this area extends along the authors considered that it constituted all the area Pacific coast fiom 5" S latitude in Ecuador to south of 30" S iatitude (Jeannel, 1967; Porter, 30" S latitude in Chile. The precipitation is 1991; Crisci el al., 1991). A third position scarce, getting to zero in Arica and Iquique (Morrone, 1996) regards it as the areas south of (Cabrera & Willink, 1980). It has a warm cli- 30" S latitude, including also the Andean regions mate and the vegetation on the coast is almost north of this latitude up to Colombia (PBramo). null, with some vegetation on the Andean slopes The 16 areas of endemism proposed (Fig. I) or bordering the watercourses descending from have been delimited by Coscardn & Coscarbn- the mountains. The region possesses numerous Arias (1995) hased on the distribution ofthe endernisms adapted to the extreme aridity con- species of Simuiiidae (Simulium and eight of the ditions. Its Pauna is quite related to that of Cen- genera of Prosimuliini). The acronyms of the tral Chile and of the Puna. The same as in the areas and their location are given in Figure I. Central Chile area, there are relicts of the I. Amazonia (AM): it is a large area repre- Antarctandean forest like that of Fray Jorge. senting the Amazon basin, It corresponds to the 7. Guiana (GU): this area includes the rain forest. It is constituted by a series of recent Guianan massif, with the Itoraima and Parima fluvial sediments and the remnants of the moun- Tepuis, together with the Orinoco plains tains of' the Brazilian and Guiana shields (CoscarOn & Coscarbn-Arias, 1995). It is an un- (Cabrera & Willink, 1980). dulated plain alternating with plateaus reach- 2. Northern Andes (NA): this is the bio- ing almost 1600 meters of altitude, with nearly geographic province named Piramo by Cahrera vertical walls. The vegetation is characterized by & Willink (1980), located in the hidean region savanna and gallery forests along the rivers. The of Venezuela, Per%, Colombia and Ecuador he- fauna of the region has been considered by some tween 2500 and 3500 meters. authors as very ancient (Jeannel, 1942,1967); it 3. Caribbean (Cia): this area occupies the was called by Ihering (1927) the Arcbiguyana plains and mountain ranges of northern Colom- Region. bia and of Venezuela north of the Orinoco, and 8. MesoamericmMomtains (lilM): it com- the Lesser Antilles. It comprises difrerent envi- prises the highland forests of the Mexican and ronments with xerophytic vegetation, and jungle Central American mountains as far south as Roig Jurie~zt& Cosca?.dn: Biogec graphical history of Simuliidae 121 J '3,, ,,P .P%, ( 11. Panrpean (Pill): this is a plain with a few hills, with steppe vegetation, and moderate precipitation diminishing toward the west. It corresponds to the biogeographic provinces of the Pampa and part or the Espinal of Cabrera & Willink (1980). Its Eauna is considered to be closely related to that of the Brazilian south- east (Rinselet, 1961). 12. Patagonlam (PA):it comprises the aus- tral part of Argentina, from the Rio Colorado to Tierra del Fuego. The Patagonian area as it is here considered includes the meridional part or the Monte of Cahrera & Willink (1980) and their biogeographic province of Patagonia (CoscarSn & Coscar6n-Arias, 1995). The steppe is the pre- vailing vegetation