Tropicohilara, a New Genus of Hilarini (Diptera: Empididae: Empidinae) from Brazil, with Descriptions of Six New Species

Simple Summary A new genus of hilarine dance fly, i.e., Tropicohilara, is described with six new included species. The new genus is recorded from the Amazon and Atlantic Forest biomes. The morphology and distribution of the genus are discussed. Abstract The genus Tropicohilara gen. nov. (Diptera: Empididae: Empidinae: Hilarini) is described and includes the following six new species from Brazil: Tropicohilara amazonensis sp. nov. (type species, Brazil: Amazonas, Manaus); T. bahiensis sp. nov. (Brazil: Bahia, Camacan); T. bella sp. nov. (Brazil: Pernambuco, Jaqueira); T. mineira sp. nov. (Brazil: Minas Gerais, Itamonte); T. paranaensis sp. nov. (Brazil: Paraná, Piraquara); and T. sinclairi sp. nov. (Brazil: Paraná, Morretes). The genus is presently recorded from the Amazonian and Atlantic Forest biomes. It differs from other hilarine genera by the following combination of characteristics: predominantly yellowish specimens; occiput somewhat conical in dorsal view; postpedicel elongate, male first fore tarsomere unmodified; hind tibia slightly shorter than hind femur; wing vein R2+3 with setae on ventral surface; male tergite 7 with a sclerotized band at posterior margin, tergite 8 reduced and upwardly directed so that terminalia can be flexed forward. A key to the species is provided.


Materials and Methods
This study was based on specimens that will be deposited in the following institutions: the Invertebrate Collection of the Instituto Nacional de Pesquisas da Amazônia (INPA), Manaus, Amazonas, Brazil; the Museu Nacional do Rio de Janeiro (MNRJ), Rio de Janeiro, Brazil; the Museu de Zoologia da Universidade de São Paulo (MZUSP), São Paulo, Brazil, and the Muséum national d'Histoire naturelle (MNHN), Paris, France.The specimens were collected with Malaise traps, Shannon traps, and light traps in the Amazonian biome of Amazonas state, and the Atlantic Forest biomes of Bahia, Minas Gerais, Paraná, and Pernambuco states.The registration number in the National System for the Management of Genetic Heritage and Associated Traditional Knowledge (SisGen) is AF8BE54.
The general morphological terminology follows Cumming and Wood (2017) [32].The specimen length was measured in lateral view from the frons (excluding antenna) to the apex of the abdomen.
The male genitalia of the specimens were macerated in hot (150 • C) 85% lactic acid for approximately 30 min, and then examined in glycerin on an excavated slide.After study and illustration, the dissected terminalia were placed in a microvial with glycerin, and then mounted below the specimen on the same pin.
The photographs were taken using a Leica DFC500 digital camera fitted onto a Leica MZ205 stereomicroscope connected to a computer with the Leica Application Suite LAS V3.6 software, including an Auto-Montage module (Syncroscopy software) which combines multiple serial layers of photographs into a single fully focused image.
Label data for the same specimen, but from different labels, are separated by quotation marks ("").The original label data have been given verbatim for the type specimens.Square brackets ([ ]) are used to indicate complementary data not included on the labels.urn:lsid:zoobank.org:act:589E8A8E-CDDE-4035-82B0-FC29CD0A2BCB

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Gender: feminine Etymology: The generic name is derived from Greek tropikus, i.e., a turning or solstice, and the generic name Hilara, and refers to the tropical distribution of the new genus.
Diagnosis: Body slender and predominantly yellow, occiput somewhat conical in dorsal view, postcranium yellow, with sparse grey pruinosity; frons and face shiny yellow without pruinosity; postpedicel elongate; scutum entirely yellow or with dark spots or stripes present; acrostichals, dorsocentrals, and supra-alars reduced to setulae; laterotergite bare; all legs slender; fore tibia without distinct anteroapical comb; hind tibia slightly shorter than hind femur; male first fore tarsomere not swollen, almost equal in length to the length of tarsomeres 2-5 combined; all legs densely covered mostly with short black setae, without strong setae; costal vein circumambient; vein R 1 distinctly swollen before joining costa; vein Sc incomplete; vein R 1 bare; vein R 2+3 with setae on ventral surface; vein R 4+5 branched, with R 4 diverging at 45 • angle and slightly sinuate, and R 5 ending beyond wing apex; abdominal tergites covered with many distinct fine setae dorsally and laterally; male tergite 7 with a sclerotized band at posterior margin and tergite 8 reduced and upward directed so that terminalia can be flexed forward; male cercus divided into a smaller basal plate and cercus, this with an apical sinus and fused laterally with subepandrial sclerite; epandrium with distinct posterodorsal lobe; postgonite sinuous, widened medially; ejaculatory apodeme flattened, plate-like, dorsal lamella wider; phallus elongate and conforming to hypandrium curvature.
Remarks: Tropicohilara gen.nov.comprises six species from the Amazon and Atlantic Forest biomes.Species occur in rainforests, and probably at higher altitudes.The only species collected in the Amazon biome, i.e., T. amazonensis sp.nov., was collected with Malaise and light traps set on a metal tower which was level with the top of the canopy at 32 m in a tropical forest north of Manaus, Amazonas, indicating that this species also inhabits the canopy.
Tropicohilara gen.nov. is easily distinguished from other genera by the combination of the following characteristics: species predominantly yellow having the occiput somewhat conical in dorsal view, the postpedicel elongate, the male first fore tarsomere not swollen, a sclerotized dark band at the posterior margin of male tergite 7, and setae on the ventral surface of vein R 2+3 .This last characteristic is also found in the monotypic Chilean genus Pasitrichotus Collin, 1933, however setae are present on both the ventral and dorsal sides of the vein; in addition to setae on R 2+3 , most veins of Pasitrichotus also have setae, both beneath and above.
In Empidinae, setae on the wing veins are also observed on the dorsal side of vein R 1 of some undescribed species of Hilara from Australia and some Patagonian species of the tribe Empidini (e.g., Empis fulvicollis Collin, 1933), and on the dorsal and ventral sides of vein R 1 in species of the genus Deuteragonista Philippi, 1865 (Collin 1933) [27].-Halter dark brown to black (Figure 10E).Tergite 8 with anterior and posterior margins somewhat straight (Figure 11B).Male postgonite more robust and bifurcated at the tip (Figure 11F) .Diagnosis: Labrum yellow except tip dark brown to black.Scutum, all femora, and tibiae entirely yellow.Wing membrane slightly brown infuscated, pterostigma not visible.Tergite 1, base and posterior margin of tergite 2 and tergite 7 yellow, remaining tergites mostly brown dorsally, yellow on posterior and lateral margins; tergite 7 yellow with dark sclerotized band on posterior margin; terminalia yellow.Description: Male.Length 5.7 mm.Head (Figure 1A-C): Ocellar triangle yellow with whitish ocelli.Postcranium yellow, with sparse grey pruinosity and short pale setae; labrum shiny yellow but dark brown to black at tip; labellum yellow; antennal scape, pedicel and base of postpedicel yellowish brown, remaining of postpedicel black.Thorax (Figure 1A,C) yellowish-orange with pale yellow postpronotal lobe, without distinct pruinosity; mesopleuron yellow with whitish areas ventrally; scutellum with three pairs of brownish marginal setae, some adjacent short setae.Legs (Figure 1A): All legs yellow except hind tarsus whitish.Wing (Figure 1A,D): Length 5.9 mm.Slightly brown infuscate; bc and c cells light brown.Halter whitish yellow.Abdomen (Figure 1A,E): Tergite 1, base and posterior margin of tergite 2 and tergite 7 yellow, remaining tergites mostly brown dorsally, yellow on posterior and lateral margins; tergite 7 light yellow with narrow dark sclerotized band on posterior margin.Tergites 2-7 densely covered with relatively short setae dorsally and laterally.Sternites yellow, covered with short pale setae (Figure 2A,C).Tergite 8 reduced, rectangular, with black setae on posterior margin, slightly lighter anteromedially (Figure 2A,B).Terminalia (Figure 2A-G) mainly yellow.Postgonite with same thickness along most of its length tapered apically, with small sinus at tip (Figure 2G).

Female. Unknown
Etymology: The specific name refers to the state where the specimens were collected, Amazonas, Brazil.
Geographical record: Brazil (Amazonas state, Manaus) (Figure 16).Bionomics: Specimens were collected only in the canopy with Malaise and light traps from March to June.Diagnosis: Labrum reddish brown basally, grading to black on extreme apex.Scutum entirely yellowish orange.Fore and mid legs dark yellow; hind leg yellow except apical two thirds of femur dark brown and basal half of tibia brownish.Wing membrane slightly brown infuscate, pterostigma not visible.Abdominal tergites 1-6 dark brown to black, tergite 7 dark yellow with a dark sclerotized band on posterior margin.Terminalia yellowish.
Etymology: The specific name refers to the state where the specimens were collected, Bahia, Brazil.
Geographical record: Brazil (Bahia state) (Figure 16).Bionomics: Specimens were collected on May using a light trap.Diagnosis: Labrum yellow except tip black.Scutum yellow with two pairs of large black spots laterally, between the dorsocentral rows and notopleuron.All legs yellow except hind femora with dark brown ring apically, hind tarsomeres whitish yellow.Wing membrane hyaline, pterostigma not visible.Abdominal tergites 1-6 and 8 mostly dark brown dorsally, yellowish on posterior and lateral margins; tergite 7 yellow with a dark sclerotized band on posterior margin; terminalia brown.Description: Male.Length 4.6 mm.Head (Figure 6A-D): Ocellar triangle dark brown to black with yellowish ocelli.Postcranium with short yellow setae.Labrum yellow, except tip black; labellum yellow; antennal scape and pedicel yellowish brown, postpedicel yellow at base remaining dark brown to black.Thorax (Figure 6D): Yellow, with two pairs of large black spots laterally on mesoscutum, between the dorsocentral rows and notopleuron; scutellum with fringe of brownish marginal setae.Legs (Figure 6A): All legs yellow except hind femora with dark brown ring apically, hind tarsomeres whitish yellow.Wing: Length 6.1 mm.Membrane hyaline, pterostigma not visible; bc and c cells light brown infuscate.Halter yellow.Abdomen (Figure 6E); Tergites 1-6 mostly dark brown dorsally, yellowish on posterior and lateral margins; tergite 7 yellow with dark sclerotized band on posterior margin (Figure 7A,B).Tergites densely covered with relatively short setae dorsally and laterally.Tergite 8 reduced, brown, with small medial sinus and black setae on posterior margin (Figure 7A,B).Sternites 1-7 yellow, covered with short pale setae; sternite 8 brown (Figure 7A,C).Terminalia with dark brown epandrium and hypandrium, but distinctly yellow cercus (Figure 7A,C-F); epandrium clearer emarginate on dorsal margin (Figure 7E).Postgonite robust, widened medially (Figure 7F).Female.Unknown.
Etymology: The specific name derives from the Latin word bellus = beautiful.Geographical record: Brazil (Pernambuco state) (Figure 16).

Bionomics:
The single known specimen of this species was collected in May using a light trap.Diagnosis: Labrum reddish brown basally, grading to black on distal third.Scutum mostly yellow with two large reddish-brown stripes medially, between the acrostichal and dorsocentral setae.Fore and mid legs dark yellow; hind leg yellow except apical two thirds of femur dark brown and tibia yellowish brown.Wing membrane light brown infuscate except apex of basal costal and costal cells brown, pterostigma brown present under apex of vein R 1 .Abdominal tergites 1-6 and 8 mostly dark brown dorsally, whitish yellow on posterior and lateral margins, tergite 7 yellowish brown with dark sclerotized band on posterior margin.
Description: Male.Length 5.2 mm.Head (Figure 8A-D): Ocellar triangle dark brown to black with yellowish ocelli.Postcranium with brownish setae.Labrum reddish brown basally, grading to black in apical third; palpus dark yellow; labellum yellow; antenna dark brown.Thorax (Figure 8D): Mostly yellow, mesoscutum with two large dark reddish-brown stripes medially, between the acrostichal and dorsocentral setae.Scutellum with two distinct pairs of brownish marginal setae, with some adjacent short setae.Legs (Figure 8A): Fore and mid legs dark yellow; hind leg yellow except apical two thirds of femur dark brown and tibia yellowish brown.Wing (Figure 8E): Length: 7.2 mm.Wing membrane light brown infuscate except basal costal cell and almost entire costal cell brown; pterostigma brown, narrow under apex of vein R 1 .Halter with base whitish yellow, remaining brown.Abdomen (Figure 8F): Tergites 1-6 and 8 mostly dark brown dorsally, whitish yellow on posterior and lateral margins; tergite 7 yellowish brown with dark sclerotized band on posterior margin (Figure 9B).Tergites 2-7 covered with relatively short pale setae dorsally and laterally.Tergite 8 reduced, brownish, darker posteriorly, somewhat rectangular, somewhat straight anteriorly and with narrow sinus on posterior margin (Figure 9B).Terminalia (Figure 9A,C-F) with dark brown epandrium, hypandrium, and cercus.Postgonite bifurcated at tip (Figure 9F).Female.Unknown.
Etymology: Noun in apposition, refers to the state where the material of the new species was collected, Minas Gerais, Brazil.
Geographical record: Brazil (Minas Gerais state) (Figure 16).Bionomics: Specimens were collected in January using Shannon and Malaise traps.Diagnosis Labrum dark brown to black.Scutum entirely yellowish orange.Fore and mid legs yellow with tibiae and tarsomeres darker; hind leg yellow except distal two thirds of femur, entire tibia, and tarsomeres 4 and 5 dark brown to black.Wing membrane light brown infuscate except apex of basal costal and entire costal cells brown, pterostigma brown, narrow, under apex of vein R 1 .Abdominal tergite 1 with base yellow and remaining dark brown dorsally, tergites 2-6 and 8 mostly dark brown to black dorsally, somewhat yellowish laterally, tergite 7 yellow with a dark sclerotized band on posterior margin; sternites 1-7 yellow, sternite 8 brown.
Description: Male.Length 5.3 mm.Head (Figure 10A-D): Ocellar triangle dark brown to black with yellowish ocelli.Postcranium with dark setae dorsally and pale setae ventrally.Labrum entirely dark brown to black; palpus dark yellow, brown at tip; labellum brownish; antenna dark brown to black.Thorax (Figure 10D): Entirely yellowish orange, without distinct pruinosity; scutellum with one stouter pair of median marginal setae, with some adjacent short setae.Legs (Figure 10A): Fore and mid legs yellow, tibiae and tarsomeres darker; hind leg yellow except apical two thirds of femur, entire tibia and tarsomeres 4 and 5 dark brown to black; all legs with coxae and trochanters with yellow setae.Wing (Figure 10A): Length 7.1 mm.Membrane slightly brown infuscate except apex of basal costal and entire costal cells brown; pterostigma brown under apex of vein R 1 .Halter with base yellow remaining dark brown to black.Abdomen (Figure 10D): Tergite 1 with base yellow and remaining dark brown dorsally, tergites 2-6 and 8 mostly dark brown to black dorsally, somewhat yellowish laterally, tergite 7 (Figure 11A,B) yellow with dark sclerotized band on posterior margin; sternites 1-7 yellow, sternite 8 brown (Figure 11A,C).Tergites densely covered with relatively short setae dorsally and laterally.Tergite 8 reduced, with black setae on posterior margin, with anterior and posterior margins somewhat straight (Figure 11A,B).Terminalia (Figure 11A,C-F) with dark brown epandrium, hypandrium, and cercus.Postgonite bifurcated at tip (Figure 11F).Female.Body length 6.6 mm.Similar to the male, thorax and abdomen with similar color pattern (Figure 12A).Terminalia (Figure 12B-E).Tergite 8 with wide sinus on anterior margin, smaller sinus medially and distinct black setae on posterior margin; posterior margin of tergite 9 + 10 and sternite 10 rounded and pointed, respectively; cercus triangular; spermatheca subspherical.
Etymology: The specific name refers to the state where the specimens were collected, Paraná, Brazil.
Geographical record: Brazil (Paraná state) (Figure 16).Bionomics: Specimens were collected in December using a light trap.
Body length 6.6 mm.Similar to the male, thorax and abdomen with similar color pattern (Figure 12A).Terminalia (Figure 12B-E).Tergite 8 with wide sinus on anterior margin, smaller sinus medially and distinct black setae on posterior margin; posterior margin of tergite 9 + 10 and sternite 10 rounded and pointed, respectively; cercus triangular; spermatheca subspherical.Etymology: The specific name refers to the state where the specimens were collected, Paraná, Brazil.
Geographical record: Brazil (Paraná state) (Figure 16).Bionomics: Specimens were collected in December using a light trap.Diagnosis: Labrum yellow basally, grading to dark brown in apical third.Scutum mostly yellow with thin brown stripes extending over dorsocentral and acrostichal rows, and a dark brown spot anteriorly at level of acrostichal row.Fore and mid legs yellow; hind leg yellow except tibia and basal half of femur dark brown, hind tarsomeres whitish.Wing membrane hyaline, pterostigma light yellow.Abdominal tergites 1-6 and terminalia mostly dark brown dorsally, somewhat yellowish laterally, tergite 7 yellow with a dark sclerotized band on posterior margin.
Etymology: The species epithet is in honor of the entomologist Bradley Sinclair for his contribution to the authors and knowledge of the empidids.
Geographical record: Brazil (Paraná state) (Figure 16).Bionomics: Specimens were collected in January, September, and October using Malaise and light traps.

Discussion
Tropicohilara gen.nov.comprises six distinct Brazilian species, with only one species occurring in the Amazon rainforest, while the remaining five species are concentrated within the Atlantic Forest biome.The species were collected in different Brazilian states,

Discussion
Tropicohilara gen.nov.comprises six distinct Brazilian species, with only one species occurring in the Amazon rainforest, while the remaining five species are concentrated within the Atlantic Forest biome.The species were collected in different Brazilian states, including Amazonas, Bahia, Pernambuco, Minas Gerais, and Paraná, showcasing the extensive range of this new genus across four of Brazil's five geographic regions.An interesting facet of this distribution is that most of these species have been documented in the Atlantic Forest, a highly threatened biome, predominantly in high-altitude and mountainous regions.Notably, the sole species found in the Amazon, i.e., T. amazonensis sp.nov., was collected using Malaise and light traps set on a metal tower that was level with the top of the canopy at 32 m in a tropical forest north of Manaus, Amazonas, suggesting this species inhabits the canopy.The collection method for the Amazonian species, involving canopy traps on a 32 m tower, highlights the importance of innovative and non-invasive research techniques in studying and conserving high-canopy rainforest species.
Tropicohilara gen.nov. is characterized by an occiput that appears somewhat triangular when viewed dorsally (e.g., Figure 1C) and more or less horizontal when viewed laterally (e.g., Figure 3B), considered a potential synapomorphy for the genus.Another possible synapomorphy is the presence of a highly sclerotized band on the posterior margin of tergite 7, a characteristic that is present in all species.The shape of tergite 7 is sometimes modified in species belonging to other hilarine genera (personal observation), but no significant sclerotization of the posterior margin is clearly observed.However, this remains to be confirmed by studying a representative sample of hilarine species belonging to various genera.The third characteristic to take into consideration is the presence of setae on the ventral surface of vein R 2+3 .This last characteristic is also found in the monotypic Chilean genus, Pasitrichotus.
Tropicohilara gen.nov.and Pasitrichotus share the following characteristics: a thin basal fore tarsomere (sometimes present in species belonging to other genera) and the absence of a set of antero-apical setae on the fore tibia.However, the only characteristic seemingly exclusive to this group is the presence of setae on the ventral vein R 2+3 .In contrast, Pasitrichotus exhibits some unique characteristics that set it apart.For instance, Pasitrichotus exhibits a distinct ventral row of spines on the mid tibia and possesses setae on both R 1 and R 4+5 veins, both characteristics are absent in Tropicohilara gen.nov.
Tropicohilara gen.nov.has hairs on the face, along the margin of the eyes (absent in Pasitrichotus).The presence of hairs on the face is not exclusive to this genus.Many species of Hilarigona Collin, 1933, some species of Hilarempis, and Hilara also exhibit these facial hairs.
In Tropicohilara gen.nov., the hind tibia is shorter than the hind femur, a characteristic that is also found in species of Aplomera Macquart, 1839 and Hilarigona, while Pasitrichotus has hind tibia length equal to hind femur.
In summary, Tropicohilara gen.nov.and Pasitrichotus share certain morphological characteristics, such as the thin basal fore tarsomere and the absence of antero-apical setae on the fore tibia.However, they also exhibit distinct traits unique to each genus, such as the presence of on specific wing veins for Pasitrichotus and the triangular-shaped occiput and shorter hind tibia for Tropicohilara gen.nov.These differences and similarities can be useful for taxonomic classification and evolutionary studies within these genera.

Figure 16 .
Figure 16.Map of South America showing the distribution of the six species of the genus Tropicohilara in Brazil.

Figure 16 .
Figure 16.Map of South America showing the distribution of the six species of the genus Tropicohilara in Brazil.