Argentinomyia fastigata ( Fluke, 1945 )

Montoya, Augusto L. & Wolff, Marta, 2023, Taxonomic revision of the Neotropical genus Argentinomyia Lynch-Arribálzaga, 1891 (Diptera: Syrphidae), with description of 16 new species, Zootaxa 5234 (1), pp. 1-157 : 56-59

Argentinomyia fastigata ( Fluke, 1945)

( Figs 30 , 31 and 92A )

Rhysops fastigatus Fluke, 1945: 4 . Type locality: Brazil, Santa Catarina, Nova Teutonia. HOLOTYPE Male AMNH (Examined).

Refs.: Fluke, 1945: 26 ( Fig. 4 , head, lateral view, female) 28 ( Fig. 37 , male abdomen); 1957: 277 (Figs 99–100, male genitalia); Marinoni & Thompson 2004: 567 Rhysops fastigata . Fluke, 1957: 266 Rhysops fastigatus . Thompson et al. 1976: 43 Argentinomyia fastigatus . Marinoni et al. 2007: 149 Braziliana columbiana Enderlein, 1938: 202 . Type locality: Colombia. Cordillera (ST 1M 1F ZMHU). n. syn.

Type material. HOLOTYPE. Adult Male, BRAZIL. Santa Catarina, Nova Teutonia , 857 m, 4.vii.1937, F. Plaumann ( AMNH) ; PARATYPES. BRAZIL. Label with the same data as Holotype, except: (1♁, 1♀, USNM ENT 01384786 , 01406255 , 1♀, AMNH) . ALLOTYPE. BRAZIL. Label with the same data as Holotype except 17.x1936, F. Plaumann (1♀, AMNH). METATYPE. BRAZIL. Label with the same data as Holotype except 18.vii.1937, F. Plaumann (1♀, AMNH) .

Length (n= 5): Body, 7.4–8.3 mm; Wings, 5.8–6.5 mm.

Diagnosis. Face pubescence punctuate, generally with distinct transverse grooves above tubercle or very weak ones; scape a little longer than basoflagellomere but shorter than pedicel and basoflagellomere together; pro- and mesofemora entirely yellow; metabasitarsus yellow-orange, usually strongly contrasting with the dark color of the tibiae and the rest of the tarsi; abdomen with a pair of oblique yellow macula on 3 rd tergum of the male, a pair of yellow maculae on 2 nd to 3 rd terga of the female; surstylus with dorsal margin slightly concave and ventral margin slightly convex; hypandrium expanded laterally towards the apex; aedeagal lobe circular, apex rounded.

Redescription. MALE. Head ( Fig. 30A ): Face shining black with coppery reflections alongside, mid-vitta bare, shining; pollen on sides of the face white, lightly punctate and with a rather large triangular bare spot dorsal the antennal insertion; facial pollen ripple-like; a heavy white pollinose patch next to the eyes which connect narrowly to a brown pollinose spot in ocular corners of front; this spot of pollen extends toward the antennae as a fine point and is present in a longitudinal groove; tubercle low and with two to three faint transverse grooves, two just dorsal the tubercle and a third near the antennae; the pile of the face and gena whitish, of frontal triangle black. Gena black, almost bare, slightly covered with white pollen. Occiput heavily pollinose. Ocellar triangle blue-black, pile sparse and black. Antennae yellow, long, ratio 1.5:1.0:1.5, dark on apex and dorsal half of basoflagellomere; scape curved, longer than basoflagellomere and shorter than basoflagellomere and the pedicel together; arista longer than pedicel, yellow at base and dark on apical third, with pile short. Thorax ( Figs 30B–C ): Shining greenish-black, mesonotum brownish pollinose anteriorly; with three dark brown vittae, the median one slender and dilated triangularly in front of scutellum, running on its full length; the lateral ones beginning broadly at the transverse suture and narrow to obscurity about half-way to scutellum, pile yellow, long. Pleura mostly shining, pollinosity absent on anterior anepimeron, pile long, yellow with slightly black tips, underhanging hairs long. Scutellum greenish-black shining, slightly rugose on apical 1/2, pile long and yellow, fringe long and yellow. Wing ( Fig. 30C ): Hyaline, faint clouds at the cross-veins, stigma yellow-brownish; membrane microtrichose, except cell c bare basal 1/4, cells bm and r bare, cell cua bare on anterior 1/3; calypter black, the basal corner yellow, border and fringe brownish; plumula white; halter orange-yellow, capitulum slightly brownish-yellow. Legs ( Fig. 30C ): Yellow to brownish; pro- and mesofemora and tibia orange-brown; metafemur yellow on basal 2/3, all metatibia and apical two or three tarsal segments brown, pile brown, long on apical 1/3 of the femur and basal 1/3 of the tibia. Abdomen ( Fig. 30B ): Oval, with a very short and scanty pilosity; except 1 st and 2 nd terga laterally with long pilosity; 2 nd tergum with a pair of small yellow macula on each side; the 3 rd tergum with a pair of oval, yellowish macula, pointed at either end, diagonally placed; suggestions of a similar metallic pollinose macula on 4 th and 5 th terga; sterna yellow; male genitalia: surstylus in lateral view ( Fig. 31A ) with dorsal margin slightly concave and ventral margin slightly convex, shorter than broad; hypandrium in ventral view ( Fig. 31C ) expanded laterally towards the apex; aedeagal lobe in ventral view ( Fig. 31C ) circular, apex rounded.

FEMALE ( Figs 30D–F ). Similar to male except for usual sexual dimorphism and differing in the frontal triangle with two rounded brown pollinose maculae just ventral to the shining blue ocellar triangle; between them a narrow pollinose streak reaching to the shining arc above the antennae. Abdomen with a pair of yellow oblique maculae on 2 nd to 3 rd terga. Maculae on 2 nd tergum isolated from the base and slender than on 3 rd tergum, maculae on 3 rd tergum connected to the base.

Taxonomic notes. Argentinomyia fastigata is similar to A. longicornis , differing by the following combination characters: Face pubescence punctuate, generally with distinct transverse grooves above tubercle or very weak ones; scape a little longer than basoflagellomere but shorter than pedicel and basoflagellomere together ( Figs 30A, C , DF); pro- and mesofemora entirely yellow; metabasitarsus yellow-orange, usually strongly contrasting with the dark color of the tibiae and the rest of the tarsi ( Figs 30A, C , D-F); abdomen with a pair of oblique yellow macula on 3 rd tergum of the male ( Figs 30B ), a pair of yellow maculae on 2 nd to 3 rd terga of the female ( Figs 30E ). A. longicornis differs externally from A. fastigata by the antenna elongated, scape equal to the pedicel and basoflagellomere together ( Figs 44A, C , D-F); pro- and mesofemora black on basal 1/3 or more; mesotarsus with apical three tarsomeres black ( Figs 44A, C , D-F); abdomen with a pair of yellow maculae on 3 rd tergum ( Figs 44B, E ). Based on males, A. fastigata differs from A. longicornis in having the surstylus in lateral view ( Fig. 31A ) with dorsal margin slightly concave and ventral margin slightly convex [versus surstylus with dorsal and ventral margins approximately of the same width in the whole length in A. longicornis ( Fig. 45A )]; aedeagal lobe in ventral view ( Fig. 31C ) circular, apex rounded [versus aedeagal lobe with acute apex in A. longicornis ( Fig. 45C )] (see “differential diagnosis” under each species or key).

Remarks. In the revision of Melanostomini , Fluke (1945) was unable to recognize the species Braziliana columbiana due to Enderlein’s brief description, however, suggested a possible close relationship to A. longicornis . Following Enderlein, Fluke characterized B. columbiana as a species with pointed bare maculae on the sides of the face, short antenna; pedicel and basoflagellomere of the same length, three to three and a half times as long as wide. Profemur yellowish on basal 1/2, metafemur brown except yellow on basal 1/6. Abdomen with two pairs of large yellow maculae covered with gray pollinosity. According to the description, B. columbiana differed from A. fastigata in the color of the profemur which is yellow in A. fastigata and brown to dark brown on basal 1/2 of B. columbiana . Thompson (personal unpublished notes) reviewed the type specimen of Rhysops columbiana Enderlein (ST ♁ ♀ ZMHU) and pointed out that “the species has the following antennal segment proportions 1.5:1.0:1.5, the wings are bare basomedially; alula microtrichose, elongate and narrow, the second costal cell bare on basal 1/3, basal cell bare and anal cell bare on anterobasal 1/3, pteropleuron shiny; basitarsus orange, contrasting with the metatibia, apical three tarsomeres dark, abdomen with a pair of oblique maculae on 2 nd to 3 rd terga, characters state combination that clearly refers to A. fastigata ”.

Fluke (1945) keyed out the species A. fastigata in two parts of the Rhysops key. He differentiates the species as having both: a) pubescence of face punctate (couplet 6) front femora yellow (couplet 7) and b) pubescence not punctate (lightly punctate and rippled) (couplet 6´and 21) four front femora black or at least mostly dark brown (couplet 9) at most only the apex or narrow base yellow on hind femora (couplet 10’) front tibiae yellow (couplet 12’); hind femora at least one-fourth yellow basally (couplet 16’).

In the USNM collection, we found two males from Venezuela (USNM ENT 01443847–48; Figs 31D–F ) which were consistent with the description of Enderlein, the characterization of Fluke and the notes of Thompson about the type specimen of B. columbiana , where both specimens have the profemur brown. When dissecting the male genitalia and comparing it with those of A. fastigata (profemur yellow) we noted similarities in the genital structures of both morphotypes, with yellow and brown profemur, which led us to conclude that they correspond to the same species, A. fastigata . Therefore, based on the morphological evidence presented above, we conclude that the leg coloration is variable in this species, in consequence, B. columbiana Enderlein is formally proposed as a synonym of A. fastigata Fluke.

Comments. The Holotype specimen of R. fastigata is currently in the AMNH. Photos are available on their website AMNH: https://sci-web-001.amnh.org/imulive/iz.html?#details=ecatalogue. 10021026.

Geographical range. Argentinomyia fastigata (n= 31) is distributed in Argentina (Tucumán) Iguaçu Falls and Serra de Fartura in Brazil (Paraná, Santa Catarina, S„o Paulo), Colombia * (Antioquia, Risaralda), Eastern Cordillera Sur in Perú * (Cuzco) and Venezuela * (Portuguesa) ( Fig. 92A ). The species is present at low and middle altitudes (164–1426 m) in the following biogeographical domains and provinces: Northern Andes : Sabana (750 m) ; Central Andes: Yungas (2300 m) ; Paraná (164–857 m) : Araucaria Forest (850 m) , Paraná Forest (164–857 m) ; Chacoan: Chaco (1426 m) .

Non-type material examined. ARGENTINA . Formosa, -26.185775, -58.175569, 66m ( Noelia Maza , personal communication) ; Salta, -24.782192, -65.423209, 1194 m ( Noelia Maza ) ; Tucumán, Villa Nougués, -26.849763, - 65.382689, 1426 m, i.1929 , R.K. (1♁, 1♀, WIRC). BRAZIL. Paraná, Parque Estadual de Vila Velha, Ponta Grossa , -25,255591, -50,037399, 850m ; Antonina, Reserva Biológica Estadual Sapitanduva , -25,4667, -48,8333, 60 m, 25.viii.1986, PROFAUPAR (1♁, DZUP 43081 , Det. F.C. Thompson); Jundiaí do Sul, Fazenda Monte Verde , - 23,436 7, -50,2475, 520 m , 8.iii.1987, PROFAUPAR (1♀, DZUP 43145 , Det. L. Marinoni); Foz do Iguaçu ( Iguazú Falls ), -25,544167, -54,586389, 164 m , 3.v.2003, Krise, D.J. (1♀, CESC 7709 ); Santa Catarina, Nova Teutonia , - 27.183334, -52.383334, 857 m , vii.1964, F. Plaumann (1♀, AMNH); 1964–1971, F. Plaumann (3♁, 3♀, USNM ENT 01406314 , 01406357 , 01406262 ) ; iv.1969, F. Plaumann, Det. J.R. Vockeroth (3♁, CNC DIPTERA 112198–200 ) ; …, 29.vii.1938, F. Plaumann (1♁, 3♀, BMNH); …, (1♁, FMNH); São Paulo, Porto Albano, Presidente Epitacio, Rio Paraná , -21.804779, -52.045791, 267 m , x.1954, J. Lane (2♁, WIRC). COLOMBIA. “Rio Ag, 20.vi”, original label data (1♀, BMNH); Risaralda, Pueblo Rico, Cerro Montezuma Tatamá , 5,190 285, -76,058958, 1928m (1♀, CEUA 103448 ) . PERÚ. Cuzco, Machu Picchu, -13.164042, -72.545861, 2300 m , 21-24.x.1972, P. Wygosdzinsky (1♁, AMNH). VENEZUELA. Portuguesa, 10km N Biscucuy , 9.130959, -69.584114, 750 m , 9.iv.1981, A. S. Menke and L. Hollenberg (2♁, USNM ENT 01443847–48 ) .

Figures

FIGURE 4. Differences in head morphology, colouration and pollinosity patterns, frontal view: A. Leucopodella sp. (♁); B. Argentinomyia longicornis (♀);C. Argentinomyia rugosonasa (♀);D. Argentinomyia jamaicensissp. nov. (♀);E. Argentinomyia testaceipes (♀); F. Argentinomyia tropica (♀); G. Argentinomyia nigrans (♀); H. Argentinomyia browni (♀); I. Argentinomyia crenulata (♀); J–K. Argentinomyia norrbomi sp. nov. (♁): J. lateral view, K. frontal view; L. Argentinomyia longicornis (♁), lateral view; M. Platycheirus (Carposcalis) (♁), frontal view; N. Platycheirus (Tuberculanostoma) (♁), lateral view. Scale bar: 5 mm.

FIGURE 30. Argentinomyia fastigata (Fluke, 1945), male (USNM ENT 01406314): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 01406314): D. Head, frontal view; E. Dorsal view (CEUA 103448); F. Lateral view (USNM ENT 01406314). Scale bars: 5 mm.

FIGURE 31. Argentinomyia fastigata (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. Male (USNM ENT 01443847): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 37. Argentinomyia jalcaensis sp. nov., male Holotype (Natural History Museum of Denmark, Copenhagen): A. Head, frontal view; B. Dorsal view; C. Lateral view.

FIGURE 44. Argentinomyia longicornis (Walker, 1836), male (CEUA 47451): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 00007888): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 45. Argentinomyia longicornis (Walker, 1836), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 92. Geographical distribution of Argentinomyia species in South America.