Argentinomyia browni ( 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 : 44-46

Argentinomyia browni ( Fluke, 1945)

Proposed standard English name: Browni’s long-antennae flower fly.

( Figs 22 , 23 and 90D )

Melanostoma browni Fluke, 1945: 18 .

Type locality: Ecuador. Bolívar , Hacienda Talahua , 3100m. HOLOTYPE Male AMNH (Examined). Refs.: Fluke, 1945: 27 ( Fig. 27 , antenna, Fig. 28 , head, male, lateral view) 29 ( Fig. 44 , male abdomen); 1957: 276 (Figs 107–108, male genitalia)

Rhysops browni . Fluke, 1957: 266

Rhysops browni . Thompson et al. 1976: 42

Argentinomyia browni . Montoya 2016: 460

Argentinomyia browni . Montoya et al. 2017: 396

Argentinomyia browni . Marín-Armijos et al. 2017: 168

Type material. HOLOTYPE. Adult Male , ECUADOR. Bolívar, Hacienda Talahua , 3100 m, 28.iv.1939, F.M. and H. Brown ( AMNH) . PARATYPE. ECUADOR. Label with the same data as Holotype (12♁, AMNH) ; …, (1♁, CNC DIPTERA 1973 ; 1♁, USNM ENT 00058849 ; 4♁, WIRC) .

Length (n= 3): Body, 9.5–10 mm; Wings, 8.9–9.1 mm.

Diagnosis. Face carinate above tubercle, the sides thickly golden pollinose; pro- and mesolegs entirely yellow; metafemur brown on apical 2/3; Metatibia black to brown apically; abdominal maculae on 2 nd tergum extending laterally from base to apical 5/6, narrow at the base and rounded apically; surstylus with dorsal and ventral margins slightly concave; hypandrium narrowed laterally towards the apex; aedeagal lobe in ventral view with apex acute.

Redescription. MALE. Head ( Fig. 22A ): Face black, nearly perpendicular, projecting forward only slightly, tubercle low yet broad, carinated dorsally, mid-vitta broad, shining and bare; laterally golden pollinose. Frontal triangle dorsal, the shining black arc and a narrow band ventral the antenna thickly golden pollinose; face yellow pilose, frontal triangle black pilose. Gena shining black with thin, more whitish pollen, pile white. Ocellar triangle black with thin yellowish pollen, pile black. Occiput with yellow hairs dorsal, long cilia black, pollen and pile paler ventrally. Antennae reddish yellow, short, ratio 1.0:1.3:2.0, basoflagellomere longer than the scape and pedicel together; scape darker, basoflagellomere darkened on dorsal 1/2 and orange ventrally, basoflagellomere apically rounded, arista long and black, bare. Thorax ( Figs 22B–C ): Black, mesonotum shining obscured by brown pollen, with two median whitish pollinose vittae on anterior half, pile long and yellow becoming black-brown alongside. Pleura also coated with brownish pollen which is whitish posteriorly, yellow pilose. Scutellum with long black hairs with some very short golden hairs intermixed, fringe long and yellow. Wing ( Fig. 22C ): Hyaline, stigma yellow, membrane microtrichose, except bare on basal 1/3 of the anterior edge of cell bm; calypter yellow, border brown, fringe yellow; plumula yellow, halters yellow, capitulum yellow. Legs ( Fig. 22C ): Pro- and mesolegs entirely yellow, metafemur brown on apical 2/3, yellow pilose becoming black apically; metatibia black to brown apically, brown pilose; tarsi brownish apically, pile sparse, long, black on dark areas. Abdomen ( Fig. 22B ): Long and slender, black with three pairs of lineate yellow maculae, maculae on 2 nd tergum separated from the base, sides and apex; maculae on 3 rd tergum reach from base to apical 5/6; maculae on 4 th tergum similar but reaching only to apical 1/2, all isolated from sides; pile long and yellow on sides but black and shorter posteriorly; sterna yellowish, with a broad, median, black vitta, yellow pilose; male genitalia: surstylus in lateral view ( Fig. 23A ) with dorsal and ventral margins slightly concave, shorter than broad; hypandrium in ventral view ( Fig. 23C ) narrowed laterally towards the apex; aedeagal lobe in ventral view ( Fig. 23C ) with apex acute.

FEMALE ( Figs 22D–F ). Similar to male except for usual sexual dimorphism and differing in the low, sharp ridge of the face above the tubercle, which is shorter than in male, abdominal maculae shorter than in male, slightly rounded apically. According to Fluke (1945), the female of A. browni is indistinguishable from A. bolivariensis but differs from it by the presence of a carinate face above the tubercle.

Taxonomic notes. Argentinomyia browni is an elongated species, similar in appearance to the highland species A. altissima and A. bolivariensis , but can be differentiated from them by the face carinate above tubercle, the sides thickly golden pollinose ( Figs 22A, C , D-F); pro- and mesolegs entirely yellow; metafemur brown on apical 2/3; metatibia black to brown apically ( Figs 22A, C , D-F); abdominal maculae on 2 nd tergum extending laterally from base to apical 5/6, narrow at the base and rounded apically ( Figs 22B, E ). Based on males, A. browni differs from A. altissima and A. bolivariensis in having the surstylus in lateral view ( Fig. 23A ) with dorsal and ventral margins slightly concave [versus surstylus very elongated and widened ventrally, with a median sized extension in the dorsal margin in A. altissima ( Fig. 13A ); surstylus with dorsal margin slightly concave and ventral margin slightly convex in A. bolivariensis ( Fig. 21A )]; aedeagal lobe in ventral view, with acute apex in A. browni ( Fig. 23C ) and A. bolivariensis ( Fig. 21C ) [versus aedeagal lobe hearth shape, with the apical margin concave in A. altissima ( Fig. 13C )] (see “differential diagnosis” under each species or key).

Comments. The Holotype specimen of M. browni is currently in the AMNH. Photos are available on their website AMNH: https://sci-web-001.amnh.org/imulive/iz.html?#details=ecatalogue. 10021684.

Biology. Label data and field observations suggest that A. browni visits flowers of Pentacalia trianae and Libanothamus humbertii (Asteraceae) . Specimens collected using canopy Malaise trap suggest that A. browni flies in the higher tree canopy (height> 4 m).

Geographical range. Argentinomyia browni (n= 24) is distributed throughout the eastern slope of the Eastern Cordillera in Colombia * (Antioquia) both slopes of the Central Cordillera in Colombia (Antioquia) and Ecuador (Bolivar) and also found in the Cordillera de Mérida in Venezuela (Mérida) ( Fig. 90D ). The species is endemic to the Northern Andes domain, distributed at middle and high altitudes (2470–3150 m) in the provinces: Cauca (3090– 3100 m) and Magdalena (2470–3150 m). Thompson et al. (1976) recorded the species from Colombia; however, no specific locality was provided .

Non-type material examined. COLOMBIA. Antioquia, Bello, San Félix, Las Baldías, 6,330 58, -75,645620, 3150 m, Páramo, Net, 16.vii.2016, A. L. Montoya (2♁, CEUA 93078–79); Belmira, Páramo de Belmira, Páramo, Malaise canopy, 4-14.xii.2016, A. L. Montoya; J. Torres; J. P. Carmona (4♁, 3♀, CEUA 95197, 95536, 95458); …, 25.iii-5.iv.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (2♁, 1♀, CEUA 95585); …, Vereda Río Arriba, Sector Laguna de Sabanas, 6,645 901, -75,670441, 3200 m, Páramo, ex Pentacalia trianae, Net , 25.iii-5.iv.2017, A. L. Montoya; C. Rodríguez; J. D. Carmona (1♀, CEUA 93558); Betulia, Vereda El Indio La Mina Alto de San José, 6,253 434, -76,045072, 3090 m, Transición, Net, 14-18.xii.2013, C. Henao; J. Cogollo (1♁, CEUA 87096); Medellín, Santa Elena, Parque Ecológico Piedras Blancas, 6,295 895, -75,499891, 2470 m, Net, 15.ii.2009, C. Bota (1♀, CEUA 47453); Betulia, Vereda El Indio La Mina Alto de San José, 6,253 434, -76,045072, 3090 m, Net, 14.xii.2013, C. Henao; J. Cogollo (1♁, CEUA 87096); Bello, San Félix, Las Baldías, 6,330 58, -75,645620, 3150 m, Net, 16.vii.2015, A.L. Montoya (2♁, CEUA 93078–79); VENEZUELA. Mérida, Páramo Mucubaji, Laguna Negra, ex flower Libanothamus humbertii Cuatr. (Asteraceae) (89V27) 8,797 016, -70,828651, 3500 m, 29.x.1989, A.L. Norrbom (1♀, USNM ENT 01443719).

Figures

FIGURE 13. Argentinomyia altissima (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm. D–E. Natural habitus of a female specimen in Pumapaccha, Cuzco, Perú (iNaturalist catalogue number# 37168068; https://www.inaturalist.org/observations/37168068). Photo taken by ©Jared Shorma.

FIGURE 21. Argentinomyia bolivariensis (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 22. Argentinomyia browni (Fluke, 1945), male (USNM ENT 00058849): A. Head, frontal view; B. Dorsal view; C. Lateral view. Female (USNM ENT 01443719): D. Head, frontal view; E. Dorsal view; F. Lateral view. Scale bars: 5 mm.

FIGURE 23. Argentinomyia browni (Fluke, 1945), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 27. Argentinomyia crenulata (Williston, 1891), male genitalia. A. Whole genitalia, lateral view; B. Epandrium, dorsal view; C. Hypandrium, ventral view. Scale bars: 1 mm.

FIGURE 28. Argentinomyia currani (Fluke, 1937), male (USNM ENT 01406227): A. Head, frontal view; B. Detail of triangular maculae, dorsal view; C. Lateral view (Detail of black ring or smudge on the apical margin of metafemur). Female (USNM ENT 01406289): D. Head, frontal view; E. Detail of triangular maculae, dorsal view; F. Lateral view. Scale bars: 5 mm.

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 90. Geographical distribution of Argentinomyia species in the Tropical Andes.