Tabanids in South America

The text provides information on taxonomy, morphological data, distribution, and bionomy on most recorded species of tabanids in South America. The distribution parameters of spe‐ cies according to classification by biogeographical regions are used. An appendix indicating the main studies about tabanids according to the countries of their origin is still offered.


Introduction
The species of family Tabanidae Latreille, 1802, commonly known in South America as " mutucas," "botucas," "mbutú," "colihuacho," and "moscas de los caballos", comprises more than 4400 worldwide species, absent only in the regions of higher altitudes and eternal snows [1,2], with more than 1800 species present in the Neotropics [3]. They are the largest bloodsucking Diptera, reaching up to 25 mm, with a robust body and some with well-developed proboscis, an aspect that causes respect and fear. Females often require blood meal for maturation of eggs, at least after the first posture, so they are considered autogenous, partially autogenous, or nonautogenous [4]. Males are phytophagous, but females, always in search of blood, repeatedly attack humans, domestic and wild animals, among primates, rodents, alligators, snakes, turtles, and birds, especially during the drier seasons [5][6][7][8]. Tabanids are known worldwide for its painful sting and are mechanical and biological vectors of several helminths, viruses, bacteria, and protozoa, etiologic agents of diseases that can affect humans and wild and domestic animals [9][10][11]. Tabanids have the characteristics necessary for a good mechanical vector: interruption of hematophagism, high mobility, and large mouthparts that can carry blood [10]. The painful tabanid sting is recognized as a determining factor to interrupt blood meal. The sting causes reactions in the host,
Tabanids in South America http://dx.doi.org/10.5772/67108 America especially in Chile and Argentina, only the primitive species can be found. Other primitive species occur in eastern Nearctic region, temperate South Africa, Northeast Asia and Japan, and eastern and southeastern Australia. The more specialized representatives occur in the Old World tropical and southern Africa, Madagascar, Seychelles, Indonesia, New Guinea, and Australia with few species in India and Southern China. The South-American species of Bouvieromyiini tribe are species that occur in the temperate regions of central Chile and Southeast Argentina (Chacoan subregion), and belong to the single subgenus of tribe.  [43,44].  (Ricardo, 1915) This genus comprises only three species in the subgenus Coracella (Philip, 1960 (Philip, 1960) Pseudotabanus (Coracella) araucana Coscarón, Pseudotabanus (Coracella) carbo (Macquart), and Pseudotabanus (Coracella) rubricornis (Kröber). The first species occurs in Chile and Argentina [46] and the latter two only in Chile [34]; Pseudotabanus (Coracella) araucana is considered by Coscarón and Papavero [20] as araucanus. Coscarón [47] reviewed the subgenera Coracella, as belonging to the genus Mesomyia Macquart 1850, which continued to appear [46] until the research publication by Fairchild and Burger [34], in which Coracella is considered as subgenus Pseudotabanus; in the same study, Coscarón [47] described Pseudotabanus (Coracella) araucana and provided a key to separate the three species.

Tribe Chrysopsini Blanchard, 1840
This comprises less restrictive species in habitats, and are separated from Bouvieromyiini by first antennal segment longer than width, near always at least twice as long as width, the third with basal plate and four annuli, antennae longer than width of head, callus generally as wide as high or wider, eyes speckled or with a specific pattern of spots and bars [19]. Most species occur in tropics in South America and Africa, but they are well represented in the Nearctic and Palearctic regions, but few eastern, Australian, or Chilean species. Only two genera are present in the Neotropics, Chrysops Meigen, 1803 and Silvius Meigen, 1820, but only the first is present in South America.

The genus Chrysops Meigen, 1803
It is represented worldwide and brings together 75 species in Neotropics, from Mexico to Argentina, of which 52 are South American [20]. In epidemiological and diagnosis of tabanofauna studies, the Chrysops species are more reported in South America. Chrysops variegatus (DeGeer) in Paraguay is a possible vector of the equine disease "mal de caderas," caused by Trypanosoma evansi [48]. It was the most abundant species observed in a survey performed in Aregua, central Paraguay [49]. Rafael and collaborators [50] captured C. variegatus on Maraca Island, Amazonian subregion, Guyana province. Bermúdez and Bermúdez described the larvae and pupae of Chrysops variegatus collected between March and April, in tropical area of high humidity and temperatures, associated with aquatic plants Pondeteria sagitata Presl and Sagittaria sp., in the livestock region of Mexico [51]. The species (as variegata) was the secondmost collected species after Lepiselaga crassipes (Fabricius) in areas of ecotone between secondary forest and pastures, in northern Colombia, Caribbean subregion [52]. The species was also collected in eastern Amazon, in areas of primary forest and pasture [53] and in Brazilian northern Amazon, also in primary forest but at 1200 meters of altitude, border Brazil-Venezuela [50]. In a survey conducted during 1995-1996 in Central Amazon four species of Chrysops were found, and the most abundant species was Chrysops formosus Kröber; the other species were Chrysops incisus Macquart, Chrysops ecuadoriensis (Enderlein), and Chrysops variegatus (DeGeer) [54]. It also occurs in central Amazon, Brazil, in primary forest and "campinaramas" ground level, and in forest canopy, 40 meters high, Amazonian Subregion, Varzea province [55][56][57]; the species was also observed in transition zone between the savannah and the Brazilian Amazon forest [58] and in Caatinga (Limeira-de-Oliveira, in personal communication). Chrysops variegatus also occurs in coastal highlands of southeast Brazilian Parana subregion [59], but was not recorded in Brazilian southern Pampa [60]. Buestán captured Chrysops variegatus in coastal zone of Ecuador, Western and Arid provinces, and Caribbean subregion [61]. Chrysops varians Wiedemann is another wide distributed species and has been captured from savannah of French Guiana [17], in pasture area in western Amazon [53], in the transition zone between the savannah and eastern Brazilian Amazon forest [58], in highlands of southeast Parana subregion [62,63], and in southern Pampa, province of Chaco subregion, in Brazil [60]. On Marambaia Island, southeast Parana subregion, Brazilian Atlantic Forest province, Chrysops variegatus and Chrysops varians were observed flying around the head and curling themselves on the hair of people who walk through forests or sandbanks [64,65].

Subfamily Pangoniinae (Rondani, 1856)
This comprises the more primitive species of tabanids. They are characterized by ninth tergite undivided in both sexes, caudal ends of spermathecal ducts without cup-like expansions, usually with 7-8 annuli in third antennal segment, ocelli and hind tibial spurs present [19]. Species are distributed in four tribes, all represented in Neotropics [20]. (Coscarón and Philip, 1979) This was created from genus Mycteromyia Philippi, 1865, characterized by elongated body, grayish or yellowish to brown, elevated ocelli at vertex, frons about as wide as high, no callus, but some rugosities above subcallus, face conically produced, wing elongated, accentuated clouds on crossveins, first posterior cell closed and petiolate [19]. The tribe is currently divided in four genera. (Kröber, 1930) This was recently placed within this tribe, with small to medium yellowish-brown species, dichoptic eyes in both sexes, widened frons, strong scutal vittae, wings with spotted crossveins, palpi small subcilindrical with reduced apical pits [66]. The genus comprises five species occurring in Central Chile and Midwest Argentina. The former genus comprised three species: Caenopangonia aspera (Philip), Caenopangonia brevirostris (Philipp) and Caenopangonia hirtipalpis (Bigot). Two new species from Chile, Caenopangonia cerdai Krolow, Henriques and González and Caenopangonia coscaroni Krolow, Henriques and González, were recently described and a key for identification of current species was provided [67]. (Philippi, 1865) This appears in Coscarón and Papavero's catalog [20] and comprises three Chilean species: Mycteromyia conica (Bigot), Mycteromyia etcheverryae Coscarón and Philip and Mycteromyia obscuripennis (Philippi). However, in Coscarón and Philip revision [68], Mycteromyia obscuripennis does not appear to be included in the genus, as well as in the tabanid list of Chile of Coscarón and González, in 1991 [46] or in the catalog of Fairchild and Burger [34]. Coscarón and Papavero [20] reported Kröber [31,69] as the reason to keep the species in the genus. Mycteromyia sp. was captured in a survey performed in summer of 1971, in province of Coquimbo, Chile (Andean region, Central Chilean subregion) [70]. González conducted morphological studies of the mouthparts of Mycteromyia conica Bigot using scanning electron microscopy [71]. (Coscarón and Philip, 1979) This brings together nine species, endemic to Chile, mainly in Andean region, Central Chile subregion [20,34,46]. Promycteromyia cinerascens (Bigot), a Chilean species, is the most well studied in the genus (as Mycteromyia) [68,72].

The tribe Pangoniini (Rondani, 1856)
This has 130 Neotropical species, more or less restricted in habitats and is considered the most ancestral species between tabanids [19,72]. They have naked eyes, prominent appendix in fork R4 vein, face not produced conically and proboscis rarely exceeding the length of the head, as frequent in Scionini [19]. With the exception of the species of Esenbeckia, specimens of this tribe are rarely collected and do not seem to be very active bloodsuckers [73]. The tribe has 14 genera in which the majority is in South America.

Genus Esenbeckia (Rondani, 1863)
This brings most tribe species, occurring throughout South America and is considered the most specialized among Pangoniini [19]. They are medium to large, slender and robust specimens, usually narrow frons, with or without a slender to clavate callus, bare eyes, usually with long proboscis and small compact labella, body pilosity short to sparse, often pattern wings [19]. The genus Esenbeckia is divided in five subgenera [20].

Subgenus Esenbeckia (Rondani, 1863)
It was reviewed by Wilkerson and Fairchild in 1985 [74], and brings together 51 species in the tropical region: Esenbeckia (Esenbeckia) rafaeli Limeira-de-Oliveira does not appear in Coscarón and Papavero catalog [20,36,75]. From neotropical species, only Esenbeckia (Esenbeckia) illota (Williston) do not occurs in the South America. In Amazonian subregion, Esenbeckia (Esenbeckia) prasiniventris (Macquart) was collected in forest in Roraima province [50], Esenbeckia (Esenbeckia) matogrossensis Lutz, in eastern Amazonian forest, Para province [53], and Esenbeckia (Esenbeckia) clari Lutz (as lemniscata Enderlein) in Pantanal province [76]. Esenbeckia (Esenbeckia) osornoi Fairchild was recorded in Cerrado province of Chacoan subregion, state of Tocantins, Brazil [77]. Esenbeckia (Esenbeckia) lugubris (Macquart) a large, glossy and dark-colored fly, with a powerful flight, and painful sting was by the first time reported in Atlantic Forest, from specimens collected on Marambaia Island, Rio de Janeiro state, Brazil [65]. (Enderlein, 1922) This comprises 38 species distributed in Central America and Mexico and will not be treated here [20]. (Philip, 1943) This comprises 11 species, all occurring in South America and ranging from Panama to Paraguay. Fairchild and Wilkerson [78] provided a key to females of 11 species of Proboscoides. They are not common in collections and there is much interspecific variation. The species mentioned in more recent studies are Esenbeckia (Proboscides) farraginis Fairchild and Wilkerson, collected in Central Brazil, Chacoan subregion, Cerrado province [77]; and Esenbeckia (Proboscoides) suturalis (Rondani), which occur in northern and eastern Amazon forest [50,53]. (Burger, 1999) and Palassomyia (Fairchild, 1969) They are monotypic with both endemic species of Chile. Esenbeckia (Astomyia) media Burger was proposed from a specimen deposited in Arthropod Collection of the State of Florida, with label written by Fairchild reading "Esenbeckia (Astomyia) media n. sp., n. subg.", leading to the conclusion that the author planned to propose these new taxa. However, Fairchild did not accomplish his purpose and Burger, describing the species, preserved the names suggested [79]. Esenbeckia (Palassomyia) fascipennis (Macquart) seems to be the least specialized among the genus Esenbeckia [19]. (Enderlein, 1922) This comprises five species, all occurring in Brazil and is a part of a more primitive group among Pangoniini [19]. They are species smaller in size, with slender, long wings, narrow forehead without callus, short proboscis, naked eyes, and has a third antennal segment with a variable number of segments [19]. The species occur only in Brazil, mainly in southeast Cerrado, Atlantic forest and Parana subregion, with one species in Amazon Basin [38]. There is record of a misidentified specimen of Protosilvius termitiformis Enderlein, in Paraná state [11,38].

Genus Veprius (Rondani, 1863)
This has five species present in Central Chile and Midwest Argentina. They are flies with head almost twice broader than height, black eyes with no band and abundant pilosity, eyespots present, broad forehead with an inconspicuous or absent callus, third antennal segment basal plate and set aside 4-style, big and little labela sclerotized [19,71]. These species occur in Central Chile and West Argentina [80]. Gonzáles described the male and re-described the female of Veprius fulvus Coscarón, Philip and Fairchild [80]. (Enderlein, 1922) This comprises species similar to those in genus Veprius, but with 8-annulate antennae, subulate, the basal plate consolidated, and pilose eyes, sometimes pilosity is sparse [19]. The genus has been reviewed by Coscarón [72] and meets four species in two subgenera.

Subgenus Curumyia (Coscarón 1976)
It has only one species Protodasyapha (Curumyia) lugens (Philippi) occurring in Chile and Argentina [20]. (Enderlein, 1922) This contains three endemic species from Central Chile [72]. González described the larvae and pupae of Protodasyapha (Protodasyapha) hirtuosa (Philippi) and compared with others Pangoniini species from Australia and North America; the larvae were found 3-5 cm beneath the soil surface of a Lithraea forest, on a steep and humid hillside [81]. (Philip and Coscarón, 1971) This comprises only two species that occur in Midwest Argentina. Coscarón considered that this genus and Chaetopalpus Philippi, 1865, form a monophyletic branch in Pangoniini [72]. The species have dark eyes, subulate antennae, frons with a circular-shaped callus, palpi with a short apical segment, sternite 8 of female very wide basally [19]. Chainey and Hall provided a picture of the front view of male head of Fairchildimyia penai Philip and Coscarón, comparing it with Boliviamyia fairchildi Chainey and Hall, the species described in that paper [73].

Genus Fairchildimyia
The other genera of Pangoniini are all monotypic: Archeomyotes Philip and Coscarón, 1971, Austromyans Philip and Coscarón, 1971 Chaetopalpus Philippi, 1865, each with an endemic species of Chile [20]. The recent genus Boliviamyia Chainey and Hall has only one endemic species from Bolivia, Boliviamyia fairchildi Chainey and Hall [73]. (Bequaert, 1930) It has only the genus Scepsis Walker, 1850 with a single Neotropical species, Scepsis appendiculata Macquart, which appears in catalogs as Scepsis nivalis Walker [20,31,34,82]. This is a slender-body fly, with whitish milky wings, atrophied mouthparts, and wide frons without callus in both sexes [19]. The species is found on sand beaches, from coast of Rio de Janeiro state (Brazil) to probably northern Argentina [19]. The species has nonhematophagous habits and can be considered autogenous. Turcatel have reports with specimen coming from Guarapuava, inside the Paraná state, Brazil, plateau region of mixed rain forest, putting in doubt the information of collection [11]. The species was observed on Marambaia Island, Rio de Janeiro, southeastern Brazil, on the white sand beaches, it has a short and low flight, not reaching more than 25 cm height and 1.5 cm away [64,65]. (Enderlein, 1922) This species have robust bodies, well-developed ocelli, no frontal callus, pilose eyes, long proboscis, and short palpi [19]. The tribe comprises over 280 species in 17 genera, austral in distribution, occurring in Australia, New Guinea, New Zealand, and South America [66]. (Enderlein, 1922) First recognized as subgenus of Scaptia [66], it has only the species Pseudomelpia horrens (Enderlein), with little body densely hairy, with robust and cylindrical palp, basal antennal ring, partial and irregularly fused with the basal plate [66]. Both male and female are nectar feeding [83]. The species is endemic to Chile, from Santiago to Maule province, Central Chilean and Subantartic regions [66].

Genus Osca (Walker, 1850)
This comprises 11 species previously placed in subgenus Scaptia, all from southeastern South American, in temperate regions and at high altitudes in Ecuador, Peru, Bolivia, and Chile [20,66]. They are moderately size flies similar to Tabanus, with short proboscis, palpi over half length of proboscis, and antennae with eight annuli [19]. González and Sanhueza using scanning electron microscopy, conducted detailed studies of the morphology and structure of the oral armor of Osca varia Walker (who does not have mandibles), Osca lata (Guérin-Meville), and rufa Osca rufa (Macquart) (all as Scaptia (Scaptia) (the latter two with mandibles with marginal teeth, suggesting bloodsucking habits) [84]. Larvae of Osca lata (Guérin-Méneville) (as Scaptia (Scaptia) were found under fallen logs in Puyehue forest area in the Patagonian, Subantartic subregion, Valdivian Forest province, Chile [85]. Fairchild, 1969 This species have moderate-size body and thick proboscis, small and reduced labella, face bulging and few projected, palpi usually short, broad, with extensive bare area [19]. The genus currently comprises six species [66]: two original species and four transferred from subgenus Scaptia (Pseudoscione) [66]. Pino and colleagues performed a survey during summer of 1971 in province of Coquimbo, Chile (Andean region, Central Chilean subregion) and found Lepmia atra (Philippi), as Scaptia (Pseudoscione), one of the most abundant species [69]. Lepmia seminigra (Ricardo), as Scaptia (Lepmia), was collected in sandbank, during early afternoon, in Parana subregion, southeast Brazilian Atlantic Forest province; the species has a powerful flight that produces loud [65].

Genus Parosca (Enderlein 1922)
This comprises medium-size species, face conspicuously projected, diverging frons, proboscis long and slender with thick labella, broad palpi extensively flattened triangular dorsally rotate [19]. Three species are included in genus, all transferred from Scaptia (Pseudoscione) [66]. The terrestrial larva of austral horsefly Parosca latipalpis (Macquart), as Scaptia (Pseudoscione), was identified by molecular techniques and described from specimens found 2-3 cm below of the soil surface and associated with larvae of Coleoptera, Lepidoptera, and Diptera in southern Chile, Osorno, and subantartic subregion [86]. (Lutz, 1918) This comprises nine species from the former subgenus Scaptia (Pseudoscione) [66]. They are from small to medium size stout species, with pale markings along sutures of scutum (like Scione), with wing cell M 3 open [66]. They are predominantly Patagonian, occurring in Chile, Argentina, also Brazil [87]. Coscarón reviewed the former subgenus Pseudoscione, and offered a key to 15 species (not for the sixteenth species), with its redescriptions and figures [66,88]. The genus Pseudoscione includes the species of former subgenus Scaptia (Pseudoscine), excluding those transferred for Lepmia and Parosca [66]. Pino and collaborators performed a survey during summer of 1971 in province of Coquimbo, Chile (Andean region, Central Chilean subregion) and found Pseudoscione dorsoguttata, as Scaptia (Pseudoscione), one of the most abundant species [70].

Genus Scione (Walker, 1850)
This comprises 41 recognized species uniformly mottled, small and slender body, and wellprojected face, undeveloped labella, slender legs, cloud marks on wing veins, closed R 3 and M 3 cells [19,66]. They are considered typically Andean species [88], occurring mainly in the mountainous regions of northwest South America, Venezuela, and Bolivia. Coscarón reviewed the genus and re-described Scione claripennis Ricardo and Scione flavohirta Ricardo, both the Andean region Argentina, also describing the male of the second species [88]. Scione aurulans (Fairchild), Scione ablusus Fairchild, and Scione flavohirta Ricardo, all were recorded to feed on man, with the latter also recorded to feed on cattle [89,90]. There is no current formally review of the genus over 80 years, and lacks descriptive and uniform descriptive characters [66].

The genus Fidena (Walker, 1850)
This comprises currently 99 species, characterized by medium to large stout body, face shining and snout-like, proboscis extremely long and slender, reduced labella and widely open wing cell M 3 [19,66]. The species of this genus are considered difficult to study, by the large number of taxa, few males have been described, great variability of characteristics and lack studies of immature stages [91]. Fidena species are widely distributed in South America, mainly mountains of southeastern Brazil and just off the subandean region [66]. They are separated into four subgenera.

Genus Pityocera (Giglio-Tos, 1896)
This species has a body from small to medium-size, with antennal flagellum with tufts of hairs on one or more flagellomeres, face projected and shiny, proboscis equal to or longer than body's length [19]. They occur in northern South America [20]. Krolow and collaborators reviewed the genus in 2015, when five new species were also described [37]. The genus comprises 10 species in three subgenera.

Subgenus Elaphella (Bezzi, 1913)
This has only one species from Subcaribbean and north Amazonian subregions, Pityocera (Elaphella) cervus (Wiedemann) [20]. The species has first flagellomere long and finger-like projection, long projections on dorsal surfaces of the second to sixth flagellomeres, and wing with stump vein on M 1 [66].

Subgenus Pityocera (Giglio-Tos, 1896)
This species has pectinate antennae, with first six antennal flagellomeres with long projections on both dorsal and ventral surfaces, seventh and eighth fused, long and finger-like. The single species, Pityocera (Pityocera) festai Giglio-Tos (festai according to Coscarón and Papavero and Fairchild; and festae according to Lessard and Krolow [20,37,66,101] occur from Panama to Ecuador, Caribbean subregion, and feeds on man [19,101]. (Kröber, 1930) This currently has eight species after the review of Krolow and collaborators [37], but only three appear in Coscarón and Papavero's catalog [20]; in these species lack the dorsal projections on antennal segments, but there is a dense dorsal patch of hairs on enlarged first annulus of third segment [19]. They occur in Ecuador, Bolivia, and Brazil, in Amazon basin [66]. The new review of Lessard on Tribe Scionini [66] did not include the new species described by South-American authors, which are not mentioned by Coscarón and Papavero [20]: Pityocera (Pseudelaphella) barrosi Gorayeb and Krolow and Pityocera (Pseudelaphella) gorayebi Limeira-de-Oliveira and Krolow, both described from Brazilian Cerrado [37], Pityocera (Pseudelaphella) pernaquila Gorayeb and Krolow, from Central and Oriental Brazilian Amazon [37] Pityocera (Pseudelaphella) rhinolissa Krolow and Henriques, from Central Brazilian Cerrado and Bolivian eastern plateau [37], and Pityocera (Pseudelaphella) ecuadorensis Buestán and Krolow, from coastal zone of Ecuador [37].

Subgenus Pseudelaphella
According to Lessard, the current genus Scaptia Walker, 1859 comprises only species occurring in Australia [66]. But in this text, the records of species of Scaptia are preserved as in major original references.

Subfamily Tabaninae
Neotropical species can be separated from the other subfamilies species by the absence of hind tibial spurs and functional ocelli, male with genitalia style truncate, ducts of spermathecal with cup-like extensions on caudal ends, eyes plain or with horizontal stripes [19]. Tabaninae are divided in two tribes: Diachlorini Lutz, 1909 and Tabanini Latreille, 1802. In neotropic species, the presence or absence of strong setae on basicosta to separate Tabanini from Diachlorini is often unreliable. In addition, others characters are used, as the sclerotized labella and vestiges of ocelli, which are common in Diachlorini but nearly unknown in Tabanini [19]. (Lutz, 1909) This includes more than half of Neotropical Tabaninae, gathering nearly 600 species in 39 genera [20]. The reading of specialized literature to study this tribe, which has a large variety of species, both primitive and specialized, is strongly recommended. The more primitive species are dull colored, from small to medium size, occurring in colder areas and include species of genera Dasybasis e Stenotabanus; the remaining species are considered more specialized, mostly, are strictly tropical [19]. Trojan [102] published study of South-American Diachlorini distribution and considered that these species "are generally restricted to the northern part of the continent", occupying the Caribbean Archipelagos, limited by Andes in eastern border, and from Santa Catarina state in Brazil to Chaco and Salta in Argentina, in South border. Following some considerations about the main genera, which include the most common species recorded in surveys conducted by South-American researchers.

The genus Acanthocera (Macquart, 1834)
This comprises 28 species resembling wasps (Hymenoptera: Vespidae). They have slender and medium-sized body, antennae very long, first antennal segment at least 1,5 times the length of the second, and third always longer than the first and second together, vestigial or absent ocelli, partially sclerotized labella, palpi slender or swollen, slender abdomen with narrowed second tergite [103,104]. Fairchild redefined the characteristics of the genus and provided a key to 16 species then known [103]. In catalog of Coscarón and Papavero [20] 20 species are listed, and it do not mention the study of Henriques and Rafael [104], where they described Acanthocera (Nothocanthocera) distinta Henriques and Rafael, transferred 11 species from the genus Nothocanthocera to genus Acanthocera, synonymized Acanthocera (Acanthocera) lutzi to Acanthocera (Acanthocera) coarctata, and the subgenus Acanthocera (Mimodynerus) Enderlein to Acanthocera (Acanthocera) Macquart. The species of Acanthocera are difficult to capture because Tabanids in South America http://dx.doi.org/10.5772/67108 they inhabit the canopy of forest [104]. The species of genus Acanthocera are currently distributed in four subgenera.

Subgenus Acanthocera (Macquart, 1834)
This subgenus has 16 species that have at least a tubercle or dorsal angle on antennal basal plate, usually a fairly long tooth or slender spine, frons rarely as wide as high, generally narrower [104]; the subgenus comprises 10 species in South America. Acanthocera (Acanthocera) longicornis (Fabricius), one of the most recorded species in studies, was captured in an ecotone area between rainforest and sandbanks on Marambaia Island, Rio de Janeiro, and in coastal zone in Parana subregion, Brazilian Atlantic Forest province [59,64,65]. (Fairchild, 1969) This comprises 12 species with short basal antennal segment, bare or partially bare frontoclypeus and gena, not wholly sclerotized labella, usually pale scutellum, without diagonal wing band, often resembling wasps [19,104]; 11 species occurring in South America and one in Central America [104]. Acanthocera (Nothocanthocera) distincta Henriques and Rafael, was omitted by Coscarón and Papavero, from Amazonian forest, Amazonian subregion, Imeri province [36,104]. (Fairchild 1969) This has the single species Acanthocera (Polistimina) politiformis Fairchild, described from a male specimen from Amapa, northern Brazil [104]. The female was also described from Amapa: this red-yellowish species resembles wasps of the genus Polistes (Hymenoptera) [104]. The immature stages of Acanthocera (Polistimina) vespiformis Burger inhabit the tunnels opened by beetles in the trunks of guanandi Callophyllum brasiliense Cambess. The larva transforms sap that flows through these tunnels into a sticky mass with bad smell that attracts flies, which are trapped and are predated by the larvae, which are always found in tunnels less than 2 m above ground [105].  It is accepted by Fairchild [32], Moucha [82], Fairchild and Burger [34], Coscarón and Papavero [20] but is not mentioned by Henriques and Rafael in their revision of the genus [104]. These are species with bare eyes, frons less than twice as high as basal width, with basal callus as wide as frons, antennae with first segment very greatly inflated and shiny, labella extensively sclerotized and shiny, basicosta lacking strong setae [19]. There are two species Acanthocera (Querbetia) chaineyi Fairchild and Burger from Ecuador and Peru, and Acanthocera (Querbetia) inopinata (Fairchild), in Peru and Bolivia [20].

Genus Agelanius (Rondani, 1863)
This comprises 12 species, and it is considered as a part of the most primitive group within the tribe Diachlorini [106]. They are brown medium-size species, narrow frons, frontal callus not touching eyes, which are pilose and without bands, without dorsal prolongation on basal flagellomere, palpi slender and elongate, bare subcallus, and with abundant setae on basicosta, so that is difficult to use keys to separate the group [19]. They are similar to Dasybasis and differ from it by narrower frons, ridge-like or clavate callus and vestigial ocelli at vertex [19]. The genus is endemic to southern South America, Subandean Patagonia province, and occurs in Peru, southern Chile, and Argentina [34,106]. During the last decade, González described Agelanius verai González [106], Agelanius fuscus González [107], Agelanius burger González [108], and Agelanius chiloensis González [109] all from Central Chile, Andean subregion. He also described the immature stages of Agelanius fuscus, which were found 5-10 cm beneath soil surface in forest of roble beech Nothofagus obliqua (Mirb.) Oerst [106] and the immature stages of Agelanius cortesi (González) collected beneath the soil surface near a small stream and with abundant Gunnera chilensis Lam. (giant-rhubarb) [110].

Genus Bolbodimyia (Bigot, 1892)
This comprises 13 species from which nine occurring in South America [20]. They are black or black and yellow, with subcallus and first antennal segment swollen and black shiny, wings wholly black, except the hyaline apex, vein R 4 strongly curved, swollen tibiae [19,111]. Theses species are infrequently collected [112]. Stone reviewed the genus and provided a key to identification of 10 species then known [112]. Gómez and collaborators recorded Bolbodimyia brunneipennis Stone, Bolbodimyia celeroides Stone, Bolbodimyia nigra Stone and Bolbodimyia philipi Stone from Venezuela, and provides a key to the identification of five species reported in the country [111].  This comprises 66 species, characterized by small size body, frons narrow, frontal callus ridge-like or clavate [19]. Kröber [113] reviewed the genus and Barretto [23] provided a key to the females in Brazil and described the males of several species. Coscarón also reviewed the genus, re-described three species and described two new from Argentina [114]. The last reference to genus was made by Turcatel, when reviewed the records of species from Parana region, southeastern Brazil [11]. The species are distributed in six subgenera.  This has seven species resembling to those in Catachlorops, from which are separated by yellow and fuses wings, often darker apical half [19]. All species occur in South America. Catachlorops (Amphichlorops) flavus Wiedemann was collected in area next to marsh and woodland in the evening, on Marambaia Island, Brazilian southeast, Parana subregion, Brazilian Atlantic Forest province [65]. They are well distributed in South America occurring in Colombia, Ecuador, Brazil, Peru, Bolivia, Paraguay, and Argentina [20].  This has 27 species occurring in South America [20]; they have small and medium-sized body, slender, callus usually clavate, brown to black tinted, black wings with a large rounded Tabanids in South America http://dx.doi.org/10.5772/67108 patch in discal cell, and hyaline apex [19]. Catachlorops (Catachlorops) halteratus Kröber and Catachlorops (Catachlorops) rufescens (Fabricius) inhabitat primary Amazonian Forest, Central Amazon subregion, Varzea province and the first was collected in February and from June to December, and the last, in April and from June to October [95]. Catachlorops (Catachlorops) leptogaster Barretto was collected in area next to marsh and woodland after 17:00 h, on Marambaia Island, Parana subregion, Brazilian Atlantic Forest province [65]. (Fairchild, 1969) This consists of six species characterized by large and stout body, hyaline wings faintly tinted, brownish or with dark cross veins margins [19]; they occur in Bolivia, Argentina and Brazil [20]. (Enderlein, 1922) This has 13 species of which 7 occur in South America [20]. They are species with very slender palpi, very long antennal tooth, often curved in apex, first posterior cell closed, coarctate or slightly narrowed discal cell, wings always hyaline at base [19]. Catachlorops (Psalidia) overali Fairchild and Rafael was captured in canopy of "terra firme" Amazonian Forest, Central Amazon, subregion, Varzea province [94]. In the same region, Catachlorops (Psalidia) rubiginosus (Summers) occurs from June to November [95]. (Fairchild, 1969) This has species related to Psalidia, but with the wing pattern reduced to an irregular small band bellow stigma and clouds around cross veins and fork of third vein [19]. This subgenus comprises nine species, and only one does not occur in South America [20]. Catachlorops (Psarochlorops) difficilis (Krober) inhabits the primary Amazonian Forest, Central Amazon subregion, Varzea province, and is collected from September to November [95]. (Enderlein, 1922) This species is characterized by clavate or ridge-like frontal callus, as wide as base frons, flagellum with hook-like projection, labella partially or wholly sclerotized, abdomen with median triangular spots most of tergites, wing with an irregular diagonal dark band [19,115]. Four species occur in southeast South America, in Brazil and one of them, Catachlorops (Rhamphidommia) potator (Wiedemann), also in northern Argentina [20]. Henriques and Krolow described Catachlorops (Rhamphidommia) dubius Henriques and Krolow, the first species of the subgenus in Amazonian subregion, Madeira province, and provided a key to determine the species within subgenus [115]. (Lutz, 1909) This was created to Tabanus mexicanus Linnaeus, without providing a description or point type species, not meeting the rules of the International Code of Zoological Nomenclature [116]. The same paper was reprinted in 1911, keeping the faults [117]. In 1913, Lutz published a paper entitled "On the Systematics of horseflies, subfamily Tabaninae", republished in 1914 [118,119]. This issue was currently discussed by Krolow and Henriques [120] and Guimarães et al. [121]. The date of 1913 was accepted for Chlorotabanus by Borgmeier [122] and Kröber [31], as well Fairchild [32]. Barretto was the first author to question the validity of the name [123]. Fairchild and Burger [34] also elected the year 1913 to designate the date of Chlorotabanus, in which were followed by Coscarón and Papavero [20,33], but not in their last manual [35]. Chlorotabanus species are crepuscular and nocturnal, greenish pale color, without frontal callus, sclerotized labella, and unicolor eyes [19]. Coscarón completed the diagnosis of the genus adding features of gentitalia [72]. The genus appears in Coscarón and Papavero catalog comprising six species [20]; but Krolow and collaborators, in an excellent review, pointed 11 valid species, from which ten occur in South America, and one species in the United States, described three new species, and described the males of Chlorotabanus leucochlorus Fairchild and Chlorotabanus flagellatus Krolow and Henriques [57]. Chlorotabanus inanis (Fabricius) and Chlorotabanus mexicanus Linnaeus occur in savannah in French Guyana [17]. In Central Amazonian, Varzea dominion, Chlorotabanus inanis was observed in two periods of activity: in the morning, between 05:20 and 05:50 h, and at afternoon, between 17:45 and 18:20 h [124]. Chlorotabanus inanis was also captured on Maraca Island, Amazonian subregion, Guyana province, and in the state of Tocantins, Brazilian Chacoan subregion, Cerrado province [50,77]. Guimarães and collaborators reported Chorotabanus inanis on Marambaia Island, Parana subregion, southeast Brazilian Atlantic Forest province; they observed that females prefer to feed on legs of horses, and when feeding, they become seemingly indifferent to the environment and are easily captured [65]. The species seems to be bivoltine, and appears from April to May and from October to December [64].  This consists of five species with one subspecies, greenish color, with reduced or absent frontal callus, antennae with strong dorsal angle or tooth, labella wholly sclerotized and clear wings; they seldom attack man and are crepuscular and nocturnal species [19]. They are present in northern Amazonian subregion and one species in Chacoan subregion, in Paraguay and Argentina [20]. Fairchild provided a good key for species of the genus [125]. Philip and Fairchild reviewed the genus as a subgenus of Chlorotabanus [126]. Coscarón elected the key features for the diagnosis of genus adding feature of genitalia [72]. Gorayeb and Fairchild provided a new key for the genus and described Cryptotylus firkin Gorayeb and Fairchild, from Amazonian subregion, province of Para [127]. Coscarón and collaborators collected larvae of Cryptotylus unicolor (Coscarón and Poi of Neif) on Pistia stratiotes Linnaeus, in ponds in a region of dry forest, northeastern Argentine, province of Formosa, Argentine Chaco [128].

Genus Dasybasis (Macquart, 184)
This is one of the most numerous in tropical fauna, with 70 valid taxa, all present in South America, and also is well represented in of southeastern Subantartic subregion, Chile and Argentina, along Andean region [19,129]. The genus comprises species that represent part of the most primitive group among Diachlorini [19]. They are species with callus filling the Tabanids in South America http://dx.doi.org/10.5772/67108 generally broad frons, or rarely reduced or absent, no tubercle at vertex, or at least, without vestigial ocelli, antennae without tooth, clear wings or clouded crossveins, and pollinose body [19]. The genus was reviewed by Coscarón and Philip in 1967, when the authors redescribed the female Dasybasis mendozana (Macquart) that occurs in the Andean pre-cordillera region in Argentina [130]; the male was described by Coscarón [131]. Coscarón also described the larva and pupa of Dasybasis nigra (Enderlein), collected at dry season, found in small pits, remaining a dry creek, in Patagonian Subregion, Central Patagonian province [132]. An unidentified species of Daybasis was found during a survey performed during summer of 1971 in province of Coquimbo, Andean region, Central Chilean subregion [70]. Dasybasis fairchildi Coscarón and Philip had described immature stages from specimens collected in cold water streams in the Peruvian Andean highlands, at 1 cm deep in the sand or among the roots of the vegetation [133]. González described the immature stages of Dasybasis (Dasybasis) nigrifrons (Philippi), and Dasybasis bruchi (Brèthes) from moss of wetlands in Central and northern Chile [134]. The same author also described the immature stages of Dasybasis pruinivitta (Kröber) and Agelanius cortesi (González) from the same region [110,135]. (Enderlein, 1922) This consists of nine brown species, with a protuberant face and very long proboscis, tri-or biramous antennae with one or two long and slender dorsal spines with erect hairs and bare eyes [19]; they occur in southeastern South America [20]. Two subgenera are recognized. (Enderlein, 1922) This has six species, five of which occur in South America in Colombia, Ecuador and Brazil [20]. (Bequaert, 1937) This has two species occurring in Ecuador, Peru e Bolivia.

Genus Diachlorus (Osten Sacken, 1876)
This comprises flies usually yellow and black colored, wings with a dark pattern, dark band in apex, colored eyes with patches and bands similar to Chrysops, variable frons, frontoclypeus bare and shiny [19]. These small flies occur in all South America, except in Chile [20]. Diachlorus has 29 species of which only Diachlorus ferrugatus (Fabricius) does not occur in South America (Central and North America). The first key to the genus was Kröber's [136], and currently the most elaborated study of the genus is Fairchild's, in which the author provided a key to identification of 23 species [137]. Coscarón added genitalia characteristics to the key characters for diagnosis of species [72]. Wilkerson and Fairchild provided a revised key and described five new species from South America [138]. Diachlorus jobbinsi Fairchild, Diachlorus bicinctus (Fabricius), and Diachlorus curvipes (Fabricius) are well distributed in northern and central Brazilian Amazonian region, in primary forest or varzea, level ground or canopy forest [50,95]. Diachlorus bivittatus (Wiedemann) is a very aggressive species, and was the most abundant species in survey performed on Marambaia Island, Parana subregion, southeast Brazilian Atlantic Forest province. The species presented two generations per year (bivoltine) [64,65]. Diachlorus distinctus Lutz was also found in that survey and has morphological and ethological similarities with Diachlorus bivittatus [65].

Genus Lepiselaga (Macquart, 1838)
This has four small and robust species of black color, glossy palps, wings with black pattern with contracted discal cell, in two subgenera [19].

Subgenus Lepiselaga (Macquart, 1838)
This has the single Lepiselaga (Lepiselaga) crassipes (Fabricius), which occurs from Mexico to northern Argentina [20]. This is a very well-studied species. Lutz observed larvae of Lepiselaga crassipes (Fabricius) on moorhen lettuce, Pistia stratiotes Linnaeus in southeast Atlantic Brazilian Forest [142]. Later, Fairchild suspected that the larvae of the species also found on Pistia in mangroves in Panama Canal Zone, would be dependent on a more complex environment, formed by a maze composed of floating debris, mats of filamentous algae, Salvinia (water fern) and small specimens of Pistia [143]. Lepiselaga crassipes was also found in Central Amazon Subregion, Varzea province [55,95] In a survey conducted in Pantanal, Brazilian Chaco subregion, the species was the fourth most abundant, occurring throughout the year, but more often in September and October [76]. The species also occurs in the transition zone between Cerrado and Pantanal, Brazil [144]. (Barretto, 1949) This comprises three species with forehead as wide as high, or wider, inflated notopleurals lobes [19], which are distributed from Western Colombia to Argentina [20].  This comprises 15 small-to medium-sized species, which have frons narrow to moderate, vertex with prominent tubercle, nearly always with vestiges of ocelli, callus clavate or ridge-like, basicosta sparsely or abundantly setose, usually black and shiny [19]. Eleven species occur in South America [20]. The genus has been well studied by Fairchild: in 1941 [145] he reviewed the genus and provided a key to 11 species with figures of eight; in 1953 [146], he reviewed the genus again and updated the key to 15 species; and, in 1985 [147] he updated the studies with a discussion of genus taxonomic position and offered a key to females of 18 species. Godoi and Rafael [148] described the immature stages of Leucotabanus albovarius (Walker) from specimens collected in rotten wood of the palm Bactris gasipaes Kunth (Arecaceae); they observed the adults active throughout the year in open areas and in primary Amazonian Forest, Central Amazon subregion, Varzea province [95]. Leucotabanus exaestuans (Linnaeus), a widely distributed species, is collected in the same environment all year long; it attacks horses and other animals on the head, near base of the ear [53,95]. Leucotabanus janinae Fairchild is another species collected in the same environment from July to December, as well as Leucotabanus palculus Fairchild, but collected from July to December [95]. Specimens of Leucotabanus sebastianus Fairchild were captured next to marsh and rain forest area, on Marambaia Island, Parana subregion, Brazilian Atlantic Forest province [65]. (Lutz, 1928) This comprises four species, three occurring in South America [20]; they are small species, with unusually long proboscis, small and partly sclerotized labella, inflated and short palpi [19]. They are similar to sarcophagids flies [149]. In 2004, Rafael and Ferreira reviewed the genus and provided a key to known species [148]. Coscarón and collaborators found larvae of Myiotabanus barrettoi Fairchild on Pistia stratiotes Linnaeus, in northeastern Argentine, province of Formosa, Argentine Chaco, region of dry forest [150].  It has 15 medium to large flies, greenish when alive or recently dead, unicolor eyes, narrow frons, slender callus, labella sclerotized, antennal plate with an obtuse dorsal angle, wings with dark markings [19]. The majority of species occurs in Brazil [20]. Phaeotabanus cajennensis (Fabricius), a large widely distributed species in South America, was captured in Trinidad using traps baited with white mice [151]. The same species was captured in canopy of "terra firme" Amazonian Forest, Central Amazon subregion, Varzea province [94]. Phaeotabanus cajennensis was also captured in ecotone between sandbank and rainforest and Phaeotabanus limpidapex (Wiedemann), and Phaeotabanus litigiosus (Walker) (more abundant from 17:00 to 19:00 h) were captured next to marsh and rain forest area on Marambaia Island, Parana subregion, Brazilian Atlantic Forest province [65]. This last species was also captured on Mel Island, coastal zone of Parana subregion, southeast Brazilian [152]. Phaeotabanus limpidapex was also captured at coastal zone of Parana subregion [59]. Phaeotabanus fervens (Linnaeus) feeds on caiman, in Pantanal and Central Amazon [95,153]. The species occur in primary forest in areas of "campinas" and "campinarana", as well as in open areas near rivers and small stream banks, in Central Amazonian subregion, Varzea province [55,95]; but according to Ferreira-Keppler and collaborators, it is active preferentially in "clareira" than forest [56]. The species was found also on Maraca Island, Amazonian subregion, Guyana province [50]. Other species captured in primary Amazonian Forest are Phaeotabanus innotescens (Walker) and Phaeotabanus nigroflavus (Kröber), both commonly collected near surface of water during drier months [95]. (Fairchild, 1943) It comprises 29 species that are small to medium size flies, slender, narrow to very narrow frons, with clavate to threadlike callus, tubercle at vertex, unicolor eyes and palpi nearly always slender [19]. An excellent review with dichotomous key for the three subgenera and eleven species of genus Philipotabanus from records in Amazon was provided by Henriques [154].  This has four species and one subspecies, similar to Philipotabanus, with a solid wing pattern, without fenestrae around cross veins, with the species all black [19]. All species occur in South America: they are largely distributed and can be seen from Panama to Midwest Brazil, in Andean areas, Amazonian Forest, and Cerrado [20]. Gorayeb and Rafael provided a key to females of species and subspecies of the genus and described Philipotabanus (Melasmatabanus) pictus Gorayeb and Rafael, from specimens collected in Pantanal subregion, Rondonia state, Brazil [155].  This comprises nine species with eight occurring in South America, Colombia, Ecuador and Peru; similar to foregoing group, they have solid wing pattern or a reduced shade below stigma, broader frons, clavate callus, and stouter palpi [19,20]. The subgenus was first characterized by Fairchild in 1964 in a key for four species, and in 1975 the author reviewed the genus and provided a key to eight species than known [156]. The last species described for the genus was Philipotabanus (Mimotabanus) tanypterus Wilkerson, 1979. Lima reports the occurrence of Philipotabanus (Mimotabanus) henriquesi Limeira-de-Oliveira, Gorayeb and Rafael, from Brazil, in Chacoan subregion, Cerrado province [77]. (Fairchild, 1943) This comprises 16 species with frons always narrow to very narrow, palpi slender, eyes bronzy in life, dark wing pattern, with hyaline fenestrae around crossveins and fork of third vein [19]. The genus is represented in Central America, but there are eight South-American species seen from Colombia to Bolivia and northern Amazon region [20]. Philipotabanus (Philipotabanus) stigmaticalis Kröber is a widely distributed species in Amazon Basin, more frequently captured in canopy of primary Amazonian Central Forest, Varzea province and is active throughout the year [94,95]. Henriques described Philipotabanus (Philipotabanus) obidensis Henriques, 2006 from eastern Peru and Bolivia, Puna subregion [154].  This comprises 74 very small to medium size species, difficult to characterize, bare eyes with at least two transverse bands, moderate to broad frons, and callus as wide as frons [19]. Seven subgenera are currently recognized [20,157]. Fairchild provided a key to the genera [158]. (Philip, 1941) This has 25 species, but only four in South America [20]. Stenotabanus (Aegialomyia) tobagensis Fairchild occurs in Trinidad, Antillean dominion, and was observed attacking man on beach and caiman [159], Stenotabanus (Aegialomyia) aberrans Philip, described from Ecuador (northwestern South American dominion, Magdalena province), Stenotabanus (Aegialomyia) geijskesi Fairchild, from Suriname (Humid Guyana province) and Brazil (Para province, Amazonian subregion), and Stenotabanus (Aegialomyia) ixyostactes (Wiedemann), from Brazil (Chacoan subregion, Cerrado province) [20,160]. (Fairchild, 1942) This has three South-American species occurring in Colombia, Venezuela, Bolivia and Argentina, with one of them also occurring in Costa Rica and Panama [20].  (Fairchild, 1969) This has only one species, Stenotabanus (Cretotatabanus) cretatus Fairchild, recorded from eastern and central Amazonia, that appears before the rainy season and is collected preferably near the ground [55,95]. (Lutz e Neiva, 1914) This subgenus comprises two species from southeast Brazil: Stenotabanus (Melanotabanus) brunnipes Kröber, 1929 and Stenotabanus (Melanotabans) fuliginosus (Lutz & Neiva), 1914. (Fairchild, 1969) There are four Brazilian species: two from Amazon and two from Cerrado. Stenotabanus (Stenotabanus) bequarti Rafael, Fairchild and Gorayeb, occurs only in Amazon, along Rio Negro and its black water tributaries, flying during drier months [95].  This has 59 species seen from Mexico to Argentina, Antilean and some in USA; 26 species are recorded from South America [156,160]. They are small to very small species, with parallel-sided frons, round or square callus as wide as frons, middle frons with dark hair patch, eyes with two bands; it is the largest subgenera in South America [19,20]. Stenotabanus (Stenotabanus) obscurus Kröber is a widely distributed species, occurring from Costa Rica to Argentina; Coscarón redescribed the female and described the male [161]. (Fairchild and Burger, 1994) This has a single species, Stenotabanus (Stenotabanus) roxannae Wilkerson, from Caribbean subregion, Chocó, Colombia [20].

The genus Stibasoma (Schiner, 1867)
This comprises 19 species that are similar to bees of the genera Centris Fabricius, Bombus Latreille, Xylocopa Latreille and Euglossa Latreille [11]. They have robust bodies, with variable colors, very pilose legs, short antenna with a long dorsal spine, inflated palpi, sclerotized labella and fringed tibiae [19]. The genus was early studied by Ricardo [162] when it comprised six species, and by Knab, in 1913, who provided a key to 10 Neotropical species [163]. Coscarón completed the diagnosis of the genus adding genitalia features [72]. All species of the genus are recorded only from South America [20]. More recently, the genus was reviewed and two new species were described from southeast Brazilian Atlantic Forest: Stibasoma manauensis Turcatel, Rafael and Carvalho, and Stibasoma ruthae Turcatel, Rafael and Carvalho [164]. The larvae of the species in this genus are usually found in water of phytotelmata of bromeliads (Bromeliaceae). Stibasoma flaviventre Macquart and Stibasoma venenata Osten Sacken develop in arboreal bromeliads and Stibasoma fulvohirtum (Wiedemann) in terrestrial bromeliads, as found in Panama [165]. Stibasoma fulvohirtum (Wiedemann), Stibasoma festifestivum (Wiedemann), Stibasoma flaviventre (Macquart), and Stibasoma currani Kröber are the most common species appearing in surveys performed in Amazon [54-56, 94, 95].  This appears in Coscarón and Papavero's catalog [20] as a subgenus of Stibasoma, but Trojan, in 1998, revalidated the genus, based on characteristics of body pilosity and leg structure [166]. The genus comprises four species from which three are recorded from South America, and one has unknown distribution [20]. Rhabdotylus planiventris (Wiedemann) and Rhabdotylus viridiventris (Macquart) were captured in an ecotone area between sandbank and rain forest, on Marambaia Island, Parana subregion, southeast Brazilian Atlantic Forest province [65].  It has only one species, Stigmatophthalmus altivagus Lutz, which occurs in southeast Brazil, and was collected in mountainous region (800-2150 m above sea level), and in an ecotone area between the sandbank and rain forest on Marambaia Island, coastal zone in Parana subregion, and southeast Brazilian Atlantic Forest province [65,167]. (Enderlein, 1914) This comprises 34 species, mostly small and slender, frons near always narrow, callus dropshaped, marked tubercle at vertex, short proboscis, soft labella, palpi somewhat slender, clouds on crossveins, or anterior or posterior infuscation, and third appendiculate vein forked [19,20]. The species can be seen from Nicaragua to Argentina, and only two species do not occur in South America [20]. Fairchild and Wilkerson reviewed the genus in 1986, including 28 species then known and provided a key to 26 of those species [168]. Coscarón elected genitalia features as key characters for define the genus [72]. Stypommisa grandicolor (Lutz) was the third most abundant species in the Central Amazon in a study conducted using Malaise trap in tropical forest [54]. Stypommisa captiroptera (Kröber), Stypommisa glandicolor (Lutz), and Stypommisa modica (Hane) are widely distributed and fairly common species captured in surveys carried out in several environments in Amazon [54-57, 94, 95].

Genus Stypommisa
Recently, Brazilian researchers proposed the following two new genera within tribe Diachlorini. (Henriques and Krolow, 2013) This has the species Muscotabanus rafaeli, which was proposed from unidentified specimens from Entomological Collection of the National Research Institute Amazon, all collected in the Central Amazon [169].
Others genera in the tribe Diachlorini are under-represented in more current surveys, and have no economic or sanitary importance.

Tribe Tabanini (Latreille, 1802)
With 207 Neotropical species characterized by setose basicosta, labella wholly pollinose, without ocelli [19,36] There are some groups of species of Leucotabanus, Stypommisa e Tabanus (those with long antennal spine) difficult to place because the setose basicosta. These problems can be solved by the study of Fairchild [19]. In Neotropics, Tabanini comprises five genera, but only three with South-American species. (Fairchild, 1961) With two South-American species, this can be seen from Colombia to Argentina [20]. Phorcotabanus cinereus (Wiedemann) occurs in Central Amazon, and was captured in "clareira," being the most abundant among the tabanid species captured in canopy of the forest [56]. (Lutz, 1921) This comprises nine species, all endemic of South America; they are mainly observed in south temperate or Andean region, but not in Chile, although Poeciloderas quandripunctatus (Fabricius) is well distributed from Mexico to Argentina [20]. It is a fairly homogeneous group, with closely related species and very similar to those of genus Tabanus. This group is understudied and lacks higher setting to characterize the species in the genus [19]. Coscarón and Fairchild reviewed the genus in Argentina and provided a key to the four species in that country [171]. The more common species captured in current surveys is Poeciloderas quandripunctatus on Central Amazon and on Maraca Island, Amazonian subregion, Guyana province [50,56]. The species was also captured in Tocantins, Brazil, Chacoan subregion, Cerrado province [77], and in southeastern Brazilian coastal zone and plateau, Parana subregion [59,63]. The species was also collected in open meadows, from 10:00 h until ca. 16:00 h, during the sunniest and hottest hours of the day, on Marambaia Island, Parana subregion, southeast Brazilian Atlantic Forest province [65]. This species is recognized having a wide distribution for all Neotropics.

Genus Tabanus (Latreille, 1802)
This comprises world-wide distributed species with bare eyes, no tubercle at vertex, short proboscis, soft labella, setose basicosta, basal plate of third antennal segment with an acute or obtuse angle, rarely with a tooth or spine; in tropical species the wings can be tinted, spotted on crossveins, margined brown veins, entirely dark or black, but never banded [19]. Coscarón and Papavero [20] listed 191 species in tropical region, of which 110 occur in South America: in their catalog lacks Tabanus bibanda considered nomen nudum [37], recorded in the southeastern Brazilian plateau, Parana Forest province, Parana subregion [61]. Fairchild [172] reported Tabanus nereus Fairchild and Tabanus eldridgei Fairchild in mangrove areas of Colombia and Ecuador, and introduced the measure of "frontal index," as a morphological key feature to tabanid identification. Coscarón reviewed the genus and provided good illustrations to identify 16 Argentine species [173]. In 1983, Fairchild published an excellent study of the Tabanus lineola complex, providing keys to males and females of South America species Tabanus [54,55,57,95]. Tabanus importunus Wiedemann is reputed as the most important vector in the Pantanal, Chaco subregion, Midwestern Brazil, being most abundant in November. It is the most common species in the region, followed by Tabanus occidentalis Linnaeus, a common species found in September and December, by Tabanus claripennis Bigot, more abundant during July to October [76]. A survey performed in Areguá, Paraguay, Chacoan subregion, Pampa province, found Tabanus triangulum Wiedemann, Tabanus secundus Walker (as stenocephalus Hine), Tabanus occidentalis Linnaeus, and Tabanus pungens (Wiedemann) among the most abundant species [49]

Tabanids and diseases
There are few studies concerning transmission of diseases caused by tabanids in South America. Most of the researchers have the scope of knowing the species found in different environments, seasonal fluctuation, and biotic and abiotic factors that affect the behavior of tabanid populations. The first author to relate tabanids with animal disease in South America was Lutz. He pointed the tabanids as the main mechanical vector of Trypanosoma evansi, the etiological agent of "mal-de-caderas" or "surra" of equines [176]. Tabanids have been recorded as an important mechanical vector of Trypanosoma vivax in South America [177]. Raymond found Trypanosoma vivax was transmitted by Tabanus importunus between zebu bulls by interrupted blood meal, in French Guiana [17]. In Colombia, three specimens of tabanid (without identification) were found infected with flagellates morphologically compatible with Trypanosoma vivax [52], and in a livestock region, was found a strong positive correlation between incidence of Trypanosoma vivax in cattle and tabanid population [14]. An experimental essay demonstrated that Tabanus nebulosus is able to transmit Trypanosoma vivax between cattle, when interrupted blodmeal is resumed within 10 minutes or less [14]. Cryptotylus unicolor was able to transmit experimentally Trypanosoma vivax between the livestock [178]. Monzón and collaborators recorded equine trypanosomiases transmitted by Tabanus sp. in Argentina [180]. Tabanids have been recorded as an important mechanical vector of Trypanosoma evansi in Brazilian and Bolivian Pantanal [179]. Outbreaks of the cattle disease Tabanids in South America http://dx.doi.org/10.5772/67108 caused by Trypanosoma evansi have been associated with the rainy season when tabanids are more abundant [15]. The most important vector of trypanosomiasis of cattle in Pantanal is Tabanus importunus and it is more abundant during the rainy season, from September/October to January [181][182][183][184][185].
Due to major environmental changes imposed by human productive activity, new interactions between agents, vectors, and hosts have occurred. A specimen of Tabanus importunus was found infected with a Leishmania sp.: the diagnosis was performed using DNA amplification technique, in São Paulo, Brazil [186]. Borrelia burgdorferi was found naturally infecting tabanids on Marambaia Island, Rio de Janeiro, southeast Atlantic Brazilian Forest (no published data from Guimarães et al). Tabanus sp. was reported as vector of human botfly, Dermatobia hominis Linnaeus Jr., in Rio Grande do Sul, Brazil [187]. In Ecuador it was reported the transmission of the botfly by Chrysops varians [188].
The following is offered as an Appendix, in which the main studies performed in South-American countries are presented.

Appendix
In this study of South American tabanids, the authors included Trinidad, because of its geographic proximity to South America mainland and by the affinity of its tabanofauna with that of South America, it is considered to be in Caribbean subregion [189]. For this aspect, Panama should also be included, but studies on tabanids in that country are very extensive and we chose to omit them. Still, many species that occur in Panama also occur in South America Caribbean subregion.
The first studies on the tabanofauna Trinidad were from Bequaert, which listed 23 species belonging to the genera Chrysops (five species), Esenbeckia, Selasoma, Stibasoma (two species), Dichelacera, Tabanus (12 species) and Acanthocera [189]. In 1944, Bequaert brought the number of species as 31, 29 in Trinidad and two in Tobago, adding a species of the genus Lepiselaga, four in genus Tabanus and Diachlorus [190]. Callan increased the number of species to 34, registering a species for each genus of Tabanus (Chlorotabanus), Stibasoma, and Fidena [191]. Fairchild and Aitken added 11 species, describing Acanthocera trinidadensis and Stibasoma flaviventre, and corrected previous errors in identification, bringing to 45 species in Trinidad [158]. The record of Phaeotabanus cajennensis on the island rose to 46 species of tabanids in Trinidad [151].
About horseflies in Guyanas, Desquesnes and Rocque published an important compilation of knowledge on biology, sanitary importance, and control of tabanids [192]. In French Guiana, a survey performed by Raymond found some differences in relative abundances of tabanids as the environment: in savannah, the most abundant species were Tabanus importunus, Tabanus occidentalis var. dorsovittatus, Tabanus wilkersoni, and Chlorotabanus mexicanus; in the rain forest the most abundant species were Phaeotabanus cajennensis, Chlorotabanus inanis, Stenotabanus cinereus, and Tabanus occidentalis. Raymond also noted that in ecotone environments, there is a greater variety of species and greater chance of finding rare species [17]. In Surinam the available information on tabanid is the Coscarón and Papavero catalog which list Tabanus antarcticus and Tabanus nebulosus; and the site InsectoidInfo points Chlorotabanus inanis as occurring in that country [20,193]. In Guyana the tabanofauna is very diverse, with species in several genera, but information is restricted to catalogs [30,32,34,82].
Studies on tabanids from Colombia were very profitable after 1940s. In 1946, Bequaert published a catalog of Colombian tabanids listing 129 species with their respective localities, and provided a key to the genera [194]. A list of 39 species of tabanids collected from Valle del Cauca, Pacific Ocean coast, was published in 1969 [195]. In 1979, Wilkerson published a list of 158 species of tabanids from Western Colombian in which are described 31 species, one subspecies and one subgenus; he also provided a checklist of 226 Colombian species [196].  [197]. In studies in Antioquia, Colombia, western region of Andes, Caribbean subregion, were recorded Lepiselaga crassipes, the most abundant species, followed by Chrysops variegatus (as variegata), Tabanus occidentalis, Tabanus claripennis, Tabanus importunus, Tabanus albocirculus, and Tabanus nebulosus. The authors also found three specimens of tabanid (without identification) infected with flagellates morphologically compatible with Trypanosoma vivax [52]. In 2016, Wolf and Miranda-Esquivel published the more currently catalogue in which are listed 256 species of Colombian tabanids [198].
In Venezuela the first list containing 31 species of tabanid was prepared by Pechuman [199]. The list was supplemented by Stone in 1944 which reported 52 species in 18 genera, and provided a key to the species of the genus Cryptotylus [200]. In savannah of the Venezuelan Caribbean subregion it was found the most abundant species Tabanus pungens, Tabanus claripennis, Tabanus antarticus, Tabanus nebulosus, Chrysops venezuelensis and Esenbeckia prasiniventris; the authors also emphasized the importance of tabanids in the transmission of bovine trypanosomiasis in the region [201]. Gorayeb and collaborators recorded 16 species to Venezuela, among the genera Fidena (four species), Catachlorops, Diachlorus (three species), Dichelacera, Dicladocera, Leucotabanus, Philipotabanus Stenotabanus, Stypommisa (three species) from deposited material the Museum of Agricultural Zoology, Institute Francisco Fernández Yépez of the Central University of Venezuela [202]. In 2005, it was published a list of 20 species of tabanids from Caribbean subregion, northern Venezuela [203]. In 2010, Gómez and collaborators reviewed some species of genus Bolbodimyia and provided a key to the recorded five species of this genus in Venezuela [111]. León in 1986 published a revisional list of 81 species of tabanids of Ecuador, providing references of original descriptions, geographical data and a key to determine the genera [205]. In 2005, Cárdenas and Vieira published a list of 42 new records, updating the knowledge of Ecuadorian tabanofauna, with 181 species [206]. In 2007, Buestán and colleagues published a list rising to 204 tabanids species of Ecuador, providing species morphological data and information about the collections environments [207]. In 2009, Cárdenas, Buestán and Dangles published studies on the diversity and distribution of tabanofauna of Ecuador and a catalog listing 198 species; in this study, the authors discussed the distribution of Chrysops varians tardus, Dicladocera macula and Fidena rhinophora using georeferenced localities and niche modeling analyses [99]. More recently, Cárdenas studied the distribution of tabanids according to altitudes and climatic factors, finding that most specimens have their activities limited by extremes temperature and humidity [98,100].
In Peru, the first specific publication on Peruvian tabanofauna was Soukoup's in 1945, which listed 81 species in the country [208], most of them were already mentioned in Kröber's catalog of 1934 [31]. In 1951, Kröber reported the result of the expedition held in southern Peru, adding 14 species to those known [209]. Philip published two lists of species, mostly from Peru, from specimens collected during an expedition of California Academy of Science to west coast of South America [210,211]. Carrasco in 1972, published a list of 163 tabanid species of which 29 were collected from southern Peru, distributed mainly in the genera Esenbeckia (seven species), Fidena (five species), Phaeotabanus (five species), Scaptia (five species), Scione (20 species), Chrysops (12 species), Stenotabanus (12 species), Dasybasis (19 species), Dicladocera (12 species), Stypommisa (eight species), and Tabanus (31 species) [212]. Wilkerson and Fairchild in 1985 provided a checklist of 228 species known from Peru, with a key to subfamilies, tribes and genera. The list includes 73 tabanid species which were collected in lowland forest, southeast Peru, Amazonian subregion, Pantanal province, considered by authors as a site of great diversity in tabanids [74].
In Bolivia, Chainey and colleagues published a preliminary list and a key to 32 genera and 167 species of tabanids, they also report tabanid collections in lowlands and mountainous areas, including grasslands, forests and wetlands, Chacoan subregion, eastern Bolivia; in this region, during August and October, cattle must be gathering in tight groups to reduce tabanid hematophagism impact on beef and milk yields [90]. Chainey and Hall proposed new genus and species, Boliviamyia fairchildi from specimens collected in the forest of the Bolivian southwest, Amazon subregion of Bolivia [73]. Coscarón re-described Dichelacera boliviensis (Brèthes) and Dichelacera micracantha Lutz from Bolivia [217]. Wilkerson provided a key of species of Stenotabanus (Brachytabanus) and described Stenotabanus (Brachytabanus) sphaeriscapus, from Bolivia [218]. Gutiérrez and Rumiz in 2002 conducted a great study to assess the degree of specialization relative to habitat of four groups of insects: among tabanids, Pseudacanthocera brevicorne (cerrado), Tabanus sorbilans (fields), Phaeotabanus fervens (riparian forest), and Tabanus nebulosus (woods gallery) were more specialized as the habitat; Tabanus occidentalis (cerrado, fields, riparian galleries and semi deciduous forests), and Lepiselaga crassipes (cerrado, fields, riparian forests and semi deciduous) were less demanding species as the habitat use [219].
About tabanids from Chile, Macquart, Rondani and Walker were the first researchers of Chilean tabanofauna [46]. They also highlights the work of Philippi, with the publication of a list of Chilean tabanids in 1865 [220]; the catalog "Insects Diptera of Chile," by Reed in 1888, which lists 61 species of tabanids in Chile [221]; and the works of Enderlein and Kröber who reviewed and published studies on the Chilean species [32,69,222]. It should be noted Pine work that offers an excellent review of studies in Chile about tabanids [223]. In 1968, Philip reviewed the types of 28 Chilean species previously described by Philippi in 1865 [221,224]. In 1973, the first study on tabanid ecology in Chile was published, from collections made using Manitoba trap in north coast of Center-Chilean subregion, recording species of the genera Scaptia (three species), Mycteromyia, and Dasybasis [70]. And in 1991, Coscarón and González published a list of 110 species of Chilean tabanids in 16 genera, with geographical distribution, bibliography, and a key to subfamilies, genera and subgenera [46]. The most recent studies on Chilean tabanids concern the description of Dasybasis elquiensis [134]; redescription of male and female of Scaptia (Pseudoscione) varies (Walker) and the male's description of Scaptia (Pseudoscione) atra (Philippi) [91]; description of female and male redescription of Dicladocera hoppi Enderlein [225]; descriptions of adults and immature stages of Agelanius fuscus [107]; adult female of Agelanius verai and Agelanius chiloensis [106,109]; description of immature stages of Scaptia (Scaptia) lata [85], Dasybasis pruinivitta [135], and Agelanius cortesi [110]; and description of Dasybasis antillanca and Dasybasis collagua [40]. Studies in wetlands ("humedales") in Chilean Andes in Centro-Chilean subregion, determined that the order Diptera is the most abundant among insects collected by Malaise trap, and in this Order, Tabanidae is the second group most abundant, after Tipulidae [226].
Tabanids studies in Paraguay are still incipient. The first study of Paraguay tabanofauna was performed by Kröber, who described three species of Poeciloderas, all currently synonymized, and two species transferred to the genus Tabanus [244]. Tabanids were implicated by Russo in transmission of Trypanosoma equinun to equine population in Paraguay since 1954 [245]. In 1977, Coscarón summarized available literature on tabanids in Paraguay [246]. Strickman [48] collected tabanids during 1978-1980, in south-central Paraguayan region, Chaquean subregion: nine species of Tabanus, five species of Chrysops, two Dichelacera, two Diachlorus, two Stypommisa, and one for each genus Acanthocera, Lepiselaga and Poeciloderas. The same author studied the seasonal variation and climatic factors on the bionomics of Chrysops variegatus, in central Paraguay, in an area adjacent to a lake, consisted of a sandy and woody strip, bordered by the lake and a grassy swamp [49]. The author also points the species as a possible vector of the equine disease 'mal de caderas,' caused by Trypanosoma evansi [48]. No other record of Paraguayan tabanids was found in literature.