Abstract
Background
The genus Tabanus Linnaeus has a worldwide distribution and is the richest in species; however, it is probably not monophyletic. In the Neotropical Region, its richness is certainly underestimated, mainly due to the large number of species and the absence of recent taxonomic revisions.
New information
We describe Tabanusrondoniensis sp. n. from the State of Rondônia, Brazil, based on a conspicuous tabanid species possibly related to the T.nebulosus species group. Diagnosis, discussion and illustrations are also provided.
Keywords: Tabanini, horseflies, Neotropics, Amazon Region, new taxon
Introduction
Tabanids are flies of medical and veterinary importance because of the haematophagous habit and the potential transmission of pathogens (Baldacchino et al. 2014). It is a large group, with some 4,500 species occupying the most varied regions of the planet. The genus Tabanus is the richest group of species, with about 1,350 described species (Pape and Thompson 2021). The Neotropical Region still holds a reasonable number of unknown Tabanus species, as can be seen from the number of species that have been described in recent decades (Fairchild 1983, Fairchild 1984, Gorayeb and Rafael 1984, Gorayeb and Barros 2006, Carmo and Henriques 2019). This paper aims to describe a new species of Tabanidae, Tabanusrondoniensis sp. n., contributing to the increase in knowledge of this family in Brazil.
Materials and methods
The material studied comes from recent captures in the State of Rondônia. The material will be deposited in the Invertebrate Collection of the National Institute for Amazonian Research (INPA). All specimens (five females) were firstly preserved in alcohol 100% , the thorax and abdomen are somewhat crumpled and the pilosity is partly missing. Traditionally, external characters are sufficient to determine species in Tabanus (Fairchild 1983, Fairchild 1984, Carmo and Henriques 2019) and the use of terminalia has not been very productive below the genus level in Tabanidae (Krolow and Henriques 2009, Krolow and Henriques 2010). For these reasons, the specimens were not dissected. The morphological terminology follows Cumming and Wood (2017).
Specimens were examined and digitally photographed through a stereomicroscope LEICA M205C coupled with a LEICA DFC 295 camera and the images were processed using the software Leica Application Suite LAS V3.6. Frons indices: Frontal index = frons height/ frons width at base; Divergence index = frons width at vertex/ frons width at base.
Taxon treatments
Tabanus rondoniensis
Henriques, Krolow, Zamarchi & Camargo sp. n.
66894B91-994C-5945-B5B2-1ADE54A64588
B66F9CEA-F03D-45CB-80FF-67E66D55A9EF
Materials
Type status: Holotype. Occurrence: recordedBy: T. Zamarchi; individualCount: 1; sex: female; Taxon: scientificNameID: urn:lsid:zoobank.org:act:B66F9CEA-F03D-45CB-80FF-67E66D55A9EF; order: Diptera; family: Tabanidae; genus: Tabanus; specificEpithet: rondoniensis; taxonRank: species; scientificNameAuthorship: Henriques, Krolow, Zamarchi and Camargo; Location: country: Brazil; stateProvince: Rondônia; municipality: Monte Negro; locality: LHC35-Sebastião; locationRemarks: transliteration: "BRAZIL, Rondônia, Monte Negro, LHC35-Sebastião, 10°09'47"S, 63°19'27"W, vii.2018, NZI trap, T. Zamarchi leg."; verbatimCoordinates: 10°09'47"S, 63°19'27"W; decimalLatitude: -10.163055555556; decimalLongitude: -63.324166666667; georeferenceProtocol: Google Earth; Identification: identifiedBy: AL Henriques, TK Krolow, TBO Zamarchi and LMA Camargo; Event: samplingProtocol: NZI trap; eventDate: 2018-07; Record Level: type: Holotype; institutionCode: INPA
Type status: Paratype. Occurrence: recordedBy: T. Zamarchi; individualCount: 1; sex: female; Taxon: scientificNameID: urn:lsid:zoobank.org:act:B66F9CEA-F03D-45CB-80FF-67E66D55A9EF; order: Diptera; family: Tabanidae; genus: Tabanus; specificEpithet: rondoniensis; taxonRank: species; scientificNameAuthorship: Henriques, Krolow, Zamarchi and Camargo; Location: country: Brazil; stateProvince: Rondônia; municipality: Monte Negro; locality: P1-Argeu; locationRemarks: transliteration: “BRAZIL, Rondônia, Monte Negro, P1-Argeu, 10°28'27"S, 63°15'18"W, viii.2019, biting horse (one female)”; verbatimCoordinates: 10°28'27"S, 63°15'18"W; decimalLatitude: -10.474167; decimalLongitude: -63.255; georeferenceProtocol: Google Earth; Identification: identifiedBy: AL Henriques, TK Krolow, TBO Zamarchi and LMA Camargo; Event: samplingProtocol: biting horse; eventDate: 2019-08; Record Level: type: Paratype; institutionCode: INPA
Type status: Paratype. Occurrence: recordedBy: T. Zamarchi; individualCount: 1; sex: female; Taxon: scientificNameID: urn:lsid:zoobank.org:act:B66F9CEA-F03D-45CB-80FF-67E66D55A9EF; order: Diptera; family: Tabanidae; genus: Tabanus; specificEpithet: rondoniensis; taxonRank: species; scientificNameAuthorship: Henriques, Krolow, Zamarchi and Camargo; Location: country: Brazil; stateProvince: Rondônia; municipality: Monte Negro; locality: P5-Necivaldo; locationRemarks: transliteration: “BRAZIL, Rondônia, Monte Negro, P5-Necivaldo, 10°06'1"S, 63°16'56"W, 2019-07, malaise in the forest (one female)”; verbatimCoordinates: 10°06'21"S, 63°16'56"W; decimalLatitude: -10.105833333333; decimalLongitude: -63.282222222222; georeferenceProtocol: Google Earth; Identification: identifiedBy: AL Henriques, TK Krolow, TBO Zamarchi and LMA Camargo; Event: samplingProtocol: malaise in the forest; eventDate: viii.2019; Record Level: type: Paratype; institutionCode: INPA
Type status: Paratype. Occurrence: recordedBy: D. Mendes, F.F. Xavier, A. Agudelo, J.A. Rafael; individualCount: 2; sex: female; Taxon: scientificNameID: urn:lsid:zoobank.org:act:B66F9CEA-F03D-45CB-80FF-67E66D55A9EF; order: Diptera; family: Tabanidae; genus: Tabanus; specificEpithet: rondoniensis; taxonRank: species; scientificNameAuthorship: Henriques, Krolow, Zamarchi and Camargo; Location: country: Brazil; stateProvince: Rondônia; municipality: Porto Velho; locality: ESEC Três Irmãos; locationRemarks: transliteration: “BRAZIL, Rondônia, Porto Velho, ESEC Três Irmãos, 09°00'09"S, 64°32'40"W, 2017-08, malaise trap, D. Mendes, F.F. Xavier, A. Agudelo, J.A. Rafael leg. (two females)”; verbatimCoordinates: 09°00′09″S; 64°32′40″W; decimalLatitude: -09.0025; decimalLongitude: -64.544444444444; georeferenceProtocol: Google Earth; Identification: identifiedBy: AL Henriques, TK Krolow, TBO Zamarchi and LMA Camargo; Event: samplingProtocol: malaise trap; eventDate: viii.2017; Record Level: type: Paratypes; institutionCode: INPA
Description
Holotype female. Length: 15.2 mm. Wing: 13 mm.
Head. Eyes unicolorous, brown in life, glabrous. Frons moderately narrow (frontal index 5.7), somewhat divergent above (divergence index 1.5) (Fig. 1C). Frontal callus brown; ocellar triangle at vertex vestigial. Subcallus, parafacial, clypeus and gena with brownish-grey pruinescence; hairs of gena yellowish-brown. Antenna brownish, darker towards the apex (Fig. 1D-E). Scape inflated and produced dorsally, cap-like, wider than first flagellomere (basal plate). Palpus yellowish-brown, first segment with long yellowish hairs, second segment predominantly with yellowish hairs and some black. Prementum dark brown. Labellum black, membranous.
Figure 1.
Tabanusrondoniensis sp. n. holotype female. A habitus, dorsal view; B habitus, lateral view; C head, frontal view; D head, lateral view; E left antenna.
Thorax. Scutum brown with mixed yellowish and black hairs. Notopleuron concolorous with scutum, covered with black hairs, white hairs dorsally. Prescutellum black, surrounded by white hairs that are also distributed throughout the brown scutellum. Pleuron and coxae brown with grey pruinescence and pale hairs; dark hairs in the upper half of the anepisternum. Legs brown predominantly with yellowish hairs; black hairs in the apical half of fore tibia, apex of mid- and hind tibia and all tarsi. Wing with normal venation, a strong angle at fork of R4+5; faintly smoky with brownish shades along of the veins in the anterior half. Pterostigma weakly brown tinted.
Abdomen. Tergites brown with black hairs, except for large white median connected triangles of hairs and pruinescence on tergites 2–5, on tergite 6 a median pale line. Sides of tergites paler with yellowish hairs. Sternites brown with yellowish hairs, except sternite 7, black haired.
Male
Not collected (unknown).
Variations
Length 15 – 17 mm. Frontal index 5.5 – 6. Divergence index 1.5 – 1.8. Although many hairs are absent, variations in the colour pattern were not diagnosed.
Diagnosis
A brownish medium-sized species with unpatterned eyes, a well marked black pilose prescutellar spot framed and margined with white hairs (Fig. 1A-B). Antennal scape inflated, wider than first flagellomere. Abdomen with a median row of large pale pilose and pruinose connected triangles on tergites 2–5, tergite 6 reduced to a narrow stripe.
Etymology
The specific name refers to the State of Brazil where the specimens was recorded, Rondônia.
Distribution
Brazil: Rondônia.
Biology
Haematophagy was confirmed through the capture of a female performing a blood meal in the horse.
Discussion
The new species described here possibly is related to T.nebulosus species-group, which has nine species and one subspecies, all Neotropical with occurrence records for Brazil or neighbouring countries, with the exception of T.punctipleura Hine, 1920, restricted to Costa Rica and Panama. According to Fairchild (1984) T.nebulosus species-group “has species with a moderately narrow and generally nearly parallel sided frons with slender clavate or ridge-like callus and fairly prominent black pilose prescutellar spot”. T.rondoniensis sp. n. can be distinguished from the other species of the T.nebulosus group by the diagnostic characters (unpatterned eyes, antennal scape inflated, wider than first flagellomere, a black pilose prescutellar spot, a median row of large pale pilose and pruinose connected triangles on tergites 2–5) and, additionally, by the wing without contrast marks; abdomen without dorso-lateral pale patches or dark median integumentary markings; palpus not reduced; unpainted costal cell and brown legs. Tabanuscomosus Stone, 1944, which has an enlarged scape and divergent frons above, can be distinguished by the presence of dorsolateral pale patches on the tergites, absent in T.rondoniensis. T.rondoniensis can be confused with T.rubripes Macquart, 1838, which also has a black prescutellum and light median triangles on the abdomen, but it has two-banded eyes, frons narrower (frontal index ca. 9), a long appendix on the fork of vein R4+5, cell r5 narrowed at apex or closed and the median pale triangles in the abdomen are not connected. Currently, 26 species of Tabanus have been registered for the State of Rondônia, of which three belong to the T.nebulosus species-group (Henriques and Gorayeb 1993, Henriques 1997,Coscarón and Papavero 2009, Carmo and Henriques 2019). T.rondoniensis is the 27th species of Tabanus and the fourth of the T.nebulosus species-group for the State of Rondônia.
Supplementary Material
Acknowledgements
To the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financial resources MCTI/CNPq/FNDCT, “Ação transversal: Redes Regionais de Pesquisas em Biodiversidade e Tecnologia”, number 79/2013 (grant 407627/2013-8), project “Biodiversidade de Insetos na Amazônia-Rede BIA”. To POSGRAD FAPEAM (2020 Edition) for financial support. To Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp) for financial resources, “Auxílios à Pesquisa” (grant 2018/09293-4) and Marlon Ferreira de Freitas for the worthy help in the fieldwork. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001”.
Funding Statement
FAPESP (Project number 2018/09293-4, by LMA Camargo)
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