Argentinomyia lineata ( Fluke, 1937 )

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 : 73-75

Argentinomyia lineata ( Fluke, 1937)

Proposed standard English name: Linear-spotted long-antennae flower fly.

( Figs 42 , 43 and 93A )

Melanostoma lineata Fluke, 1937: 9 . Type locality: Brazil. Santa Catarina, Nova Teutonia. HOLOTYPE Male AMNH (Examined). Refs.: Fluke, 1937: 5 ( Fig. 11 , male abdomen); 1945: 26 ( Fig. 7 , Head, lateral view, male); 1957: 277 (Figs 105–106, male genitalia)

Rhysops lineatus . Fluke, 1945: 7

Rhysops lineata . Fluke, 1957: 266

Rhysops lineata . Thompson et al. 1976: 43

Argentinomyia lineatus . Thompson & Skevington, 2014: 98

Type material. HOLOTYPE. Adult Male, BRAZIL. Santa Catarina, Nova Teutonia , 857 m, 2.ix.1936, F. Plaumann ( AMNH) . ALLOTYPE. BRAZIL. Label with the same data as Holotype except 7.vii.1936, F. Plaumann (1♀, AMNH) . PARATYPE. BRAZIL. Label with the same data as Holotype except 6-7.vii.1936, F. Plaumann (3♁, 2♀, AMNH) ; …, 1-2.ix.1936, F. Plaumann (1♁, 2♀, AMNH) ; ..., 1.vii.1936, F. Plaumann (1♁, 2♀, WIRC) ; Same data, except: (5♀, BMNH) .

Length (n= 4): Body, 7.5–9.2 mm; Wings, 7.3–8.0 mm.

Diagnosis. A shining black aeneous species with relatively short antennae, two faint transversal grooves above tubercle; highly polished mesonotum with two faint vittae anteriorly; abdomen with elongate linear yellow vittae; metafemur yellow on basal 1/5, pro- and mesofemora broadly yellow apically; surstylus square-like, shorter than broad; hypandrium narrowed laterally towards the apex; aedeagal lobe oval, apex rounded.

Redescription. MALE. Head ( Fig. 42A ): Face almost perpendicular with two faint transverse depressions, tubercle elongate, broad and low; mid-vitta shining black, sides white pollinose, heavier next to the eyes; pile pale, sparse. Frontal triangle rough, but shining dorsal antennae, broadly cinereous pollinose along the eyes, more whitish next to orbits, pile black. Gena shining, lightly whitish pollinose. Ocellar triangle black, with black pile; occipital pile fine, short and black. Occiput narrow, even ventral; silvery pollinose ventral. Antennae yellowish, short, ratio 1.8:1.0:1.3, scape only very little longer than pedicel which is longer than wide, basoflagellomere slightly less in length than first two together; yellowish, darker toward the end and dorsal on basoflagellomere, arista yellow at base and dark on apical third, pilose. Thorax ( Figs 42B–C ): Aeneous, mesonotum shining with a slight bronze cast, yellowish-brown pilose; with two very faint pollinose vittae on anterior half, yellow pilose. Pleura lightly coated with brownish to rusty-colored pollen, yellow pilose. Scutellum with long pile, the marginals are blackish-brown; fringe short and yellow. Wing ( Fig. 42C ): Hyaline, stigma yellow, microtrichose, except bare on basal 1/3 of cell bm, cell cua microtrichose, slightly tinged with brown; calypter wholly white-yellowish; plumula white, halter yellow, capitulum slightly brown. Legs ( Fig. 42C ): Black to brownish; metafemur yellow on basal 1/4 and the tip, pro- and mesofemora broadly yellow on apical 1/3 to 1/4, pro- and mesotibiae yellow; metatibia yellow on basal 1/3; basal segment of tarsi yellowish to brownish. Abdomen ( Fig. 42B ): Narrow with nearly parallel sides, shining black, 2 nd and 3 rd terga more opaque, each with a pair of elongate yellow maculae, apically acute, both start basally, on 2 nd tergum reaching apical 1/3, on 3 rd reaching apical 1/2 of segments; sterna yellow, brownish metallic on 2 nd sternum, only yellowish on apical 1/6, 3 rd and 4 th sternum yellow basally on 1/2 and 1/6 respectively; male genitalia: surstylus in lateral view ( Fig. 43A ) square-like, shorter than broad; hypandrium in ventral view ( Fig. 43C ) narrowed laterally towards the apex; aedeagal lobe in ventral view ( Fig. 43C ) oval, apex rounded.

FEMALE ( Figs 42D–F ). Similar to male except for usual sexual dimorphism and differing in Frontal triangle with a broad, very narrowly bisected, brownish pollinose crossband occupying the frontal depression; between this band and the ocelli a somewhat narrow black opaque band. Yellow areas on antennae and legs more extensive than on male. Wings hyaline, the abdomen more shining and there are small elongate maculae on 2 nd tergite.

Taxonomic notes. Argentinomyia lineata is similar in appearance to A. neotropica differing from it by having the face with two faint transversal grooves above the tubercle ( Figs 42A, C , D-F); highly polished mesonotum with two faint vittae anteriorly ( Figs 42B, E ); metafemur yellow on basal 1/5, pro- and mesofemora broadly yellow apically ( Figs 42A, C , D-F); 2 nd to 4 th terga with elongate linear yellow vittae ( Figs 42B, E ). In A. neotropica the face perpendicular without prominent grooves above the tubercle; ( Figs 53A, C , D-F); maculae on basal corners of the 2 nd tergum, reaching over the sides and 1/2 of segment length ( Figs 53B, E ); femora and tarsi black ( Figs 53A, C , D-F). Based on males, A. lineata differs from A. neotropica in having the aedeagal lobe in ventral view, oval, apex rounded ( Fig. 54C ) [versus aedeagal lobe with acute apex in A. neotropica ( Fig. 52C )].

Remarks. The species Melanostoma limbatum was described by Enderlein (1937) based on two males and one female syntypes collected in northern Argentina , Tucumán Province (ST ZMHU). According to the description of Enderlein (1937), the species is characterized by the pollen of the face white and punctate on female, apparently non-punctate on male. Basoflagellomere is one and two-thirds times as long as wide. Thorax shining black, with thick brownish-yellow pile. Abdomen (male) with three pairs of yellow spots, female with four pairs of yellow spots. Legs yellowish, metalegs brown except the apex and base of the femora. Fluke (1945) pointed out that he was unable to recognize this species, suggesting that M. limbatum could be Rhysops lineata Fluke (= A. lineata ). However, given that we have not accessed the type material of M. limbatum , we refrain from synonymizing it under A. lineata . In consequence, the species’ status remains doubtful.

Comments. The Holotype specimen of M. lineata is currently in the AMNH. Photos are available on their website AMNH: https://sci-web-001.amnh.org/imulive/iz.html?#details=ecatalogue.10020979.

Geographical range. Argentinomyia lineata (n= 89) is an abundant species, distributed in Serra de Fartura in Brazil (Paraná, Santa Catarina) and the Eastern slope of Cordillera Oriental Sur in Bolivia * (La Paz) ( Fig. 93A ). The species is present at low and middle altitudes (400–1274 m) in the following biogeographical domains and provinces: Central Andes : Rondônia (1100 m) ; Paraná (400–1274 m) : Araucaria Forest (1200–1274 m) and Paraná Forest (400–857 m) .

Non-type material examined. BOLIVIA. La Paz, Alto Rio Bendi, South Rio Inicua , -15,162447, -67,865439, 1100 m, 16.i.1976, L.E. Peña (2♀, AMNH) . BRAZIL. Paraná, Refugio de vida silvestre dos campos de Palmas , -26,533807, -51,599362, 1200 m, A. Couto ( DZUP) ; Santa Catarina, Nova Teutonia , -27,183334, -52,383334, 400 m, 7.i.1960, F. Plaumann (3♁, 2♀, AMNH) ; Same data, except: (2♁, 2♀, CNC DIPTERA 112204–07 ; 45♁, 12♀, USNM ENT 01406413–12 ; 01406315–17; 01406264–65; 01406390; 01406364; 01406411; 01406394; 01406279; 01406370; 0140637; 01406334; 01406212–14; 01406250; 01406368; 01406300; 0146306–07; 01406393; 01406344; 01406362; 01406276; 01406365; 01406208; 01406222; 01406406; 01406231; 01406228; 01406215; 01406282; 01406197; 01406241; 01406359; 01406387; 01406382; 01406244; 01406401; 01406335; 01406285; 01406205; 01406309; 01406319; 01406203; 01406216; 01406242; 1406298; 01406280; 01406192; 01406226; 01406200; 01443755; 01406331; 01406294; 01406356; 01406329; 01406353; 01406204; 01406253; 01406221; 01384641; 01406396; 01443760; 2♁, 1♀, FMNH) .

Figures

FIGURE 7. Schematic drawings showing colouration patterns of the posterior leg, lateral view.A. Argentinomyia crenulata; B. Argentinomyia longicornis; C. Argentinomyia ivani sp. nov.; D. Argentinomyia spinifemorata sp. nov.; E. Detail of black ring or smudge on the apical margin of metafemur of Argentinomyia praeusta; F. Argentinomyia occidentalis sp. nov.

FIGURE 11. Argentinomyia agonis (Walker, 1849), male genitalia. A. Whole genitalia including epandrium, cercus and surstylus, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view.Abbreviations used in male genitalia structures are as follows: Ahp = apex of hypandrium (superior lobes); Cer = Cercus; Epd = Epandrium; Hyp = Hypandrium; Led = Aedeagal lobe; Sur = Surstyle. Scale bar: 0.05 mm. D–E. Natural habitus of male and female specimens in Puerto Villamil, Galapagos, Ecuador (iNaturalist catalogue number37254474; https://www.inaturalist.org/observations/37254474). Photo taken by ©Robert Siegel.

FIGURE 42. Argentinomyia lineata (Fluke, 1937), male (USNM ENT 01406413): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 01406353): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 43. Argentinomyia lineata (Fluke, 1937), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 52. Argentinomyia neotropica (Curran, 1937), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. D. Natural habitus of a female specimen in Magdalena Partido, Buenos Aires Province, Argentina (iNaturalist catalogue number 6307133; https://www.inaturalist.org/observations/6307133). Photo taken by ©Gerónimo Martín Alonso.

FIGURE 53. Argentinomyia nigrans (Fluke, 1945), male (USNM ENT 01384670): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 01406441): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 54. Argentinomyia nigrans (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. D–G. Rhysops funerea (Hull, 1949), male Holotype (CNC DIPTERA 169358). D. Latero–frontal view; E. Dorsal view; F. Lateral view; G. Label.

FIGURE 93. Geographical distribution of Argentinomyia species in the North Andes and southeastern South America.